STRUCTURE magazine - May 2018

A Joint Publication of NCSEA | CASE | SEI

STRUCTURE

®

May 2018 Masonry Inside: St. Francis of Assisi Church, Virginia

Special Section:

S T R U C T U R E solutions

Clark University Alumni & Student Engagement Center

by Architerra with Odeh Engineers

LeMessurier Calls on Tekla Structural Designer for Complex Projects Interoperability and Time Saving Tools

Tekla Structural Designer was developed specifically to maximize collaboration with other project parties, including technicians, fabricators and architects. Its unique functionality enables engineers to integrate the physical design model seamlessly with Tekla Structures or Autodesk Revit, and to round-trip without compromising vital design data.

“We’re able to import geometry from Revit, design in Tekla Structural Designer and export that information for import back into Revit. If an architect makes geometry updates or changes a slab edge, we’ll send those changes back into Tekla Structural Designer, rerun the analysis and design, and push updated design information back into Revit.”

Tekla Structural Design at Work: The Hub on Causeway

For over 55 years, LeMessurier has provided structural engineering services to architects, owners, contractors, developers and artists. Led by the example of legendary structural engineer and founder William LeMessurier, LeMessurier provides the expertise for some of the world’s most elegant and sophisticated designs while remaining true to the enduring laws of science and engineering.

Known for pushing the envelope of the latest technologies and even inventing new ones, LeMessurier engineers solutions responsive to their clients’ visions and reflective of their experience.

An early adopter of technology to improve their designs and workflow, LeMessurier put its own talent to work in the eighties to develop a software solution that did not exist commercially at the time. Their early application adopted the concept of Building Information Modeling (BIM) long before it emerged decades later.

While LeMessurier’s proprietary tool had evolved over three decades into a powerhouse of capability, the decision to evaluate commercial structural design tools was predicated on the looming effort required to modernize its software to leverage emerging platforms, support normalized data structure integration and keep up with code changes.

After a lengthy and thorough comparison of commercial tools that would “fill the shoes” and stack up to the company’s proprietary tool, LeMessurier chose Tekla Structural Designer for its rich capabilities that addressed all of their workflow needs. According to Derek Barnes, Associate at LeMessurier, ” Tekla Structural Designer offered the most features and the best integration of all the products we tested. They also offered us the ability to work closely with their development group to ensure we were getting the most out of the software.”

One Model for Structural Analysis & Design

From Schematic Design through Construction Documents, Tekla Structural Designer allows LeMessurier engineers to work from one single model for structural analysis and design, improving efficiency, workflow, and ultimately saving time. “Our engineers are working more efficiently because they don’t need to switch between multiple software packages for concrete and steel design. Tekla Structural Designer offers better integration of multiple materials than we have seen in any other product,” said Barnes.

LeMessurier engineers use Tekla Structural Designer to create physical, information-rich models that contain the intelligence they need to automate the design of significant portions of their structures and efficiently manage project changes.

TRANSFORMING THE WAY THE WORLD WORKS

“Tekla Structural Designer has streamlined our design process,” said Craig Blanchet, P.E., Vice President of LeMessurier. “Because some of our engineers are no longer doubling as software developers, it allows us to focus their talents on leveraging the features of the software to our advantage. Had we not chosen to adopt Tekla Structural Designer, we would have needed to bring on new staff to update and maintain our in-house software. So Tekla Structural Designer is not just saving us time on projects, it is also saving us overhead.

Efficient, Accurate Loading and Analysis

Tekla Structural Designer automatically generates an underlying and highly sophisticated analytical model from the physical model, allowing LeMessurier engineers to focus more on design than on analytical model management. Regardless of a model’s size or complexity, Tekla Structural Designer’s analytical engine accurately computes forces and displacements for use in design and the assessment of building performance.

“Tekla Structural Designer offers better integration of multiple materials than we have seen in any other product.”

Positioning a large scale mixed-use development next to an active arena, a below grade parking garage, and an interstate highway, and bridging it over two active subway tunnels makes planning, phasing and engineering paramount. Currently under construction, The Hub on Causeway Project will be the final piece in the puzzle that is the site of the original Boston Garden.

Despite being new to the software, LeMessurier decided to use Tekla Structural Designer for significant portions of the project. “Relying on a new program for such a big project was obviously a risk for us, but with the potential for time savings and other efficiencies, we jumped right in with Tekla Structural Designer. It forced us to get familiar the software very quickly.”

“Tekla Structural Designer allowed us to design the bulk of Phase 1 in a single model,” said Barnes. The project incorporates both concrete flat slabs and composite concrete and steel floor framing. “Tekla Structural Designer has the ability to calculate effective widths based on the physical model which is a big time saver,” said Barnes. “On this project, the integration with Revit, along with the composite steel design features enabled us to work more efficiently. Adding the ability to do concrete design in the same model was a bonus because we had both construction types in the same building.”

“Tekla Structural Designer helped this project run more efficiently, and in the end it was a positive experience,” said Blanchet.

“Tekla Structural Designer gives us multiple analysis sets to pull from, which gives us lots of control. Most programs don’t have the capability to do FE and grillage chase-down. For the design of beam supported concrete slabs, Tekla Structural Designer allows us to separate the slab stiffness from the beam stiffness, so if we choose to we can design the beams without considering the influence of the slab. In the same model we can use a separate analysis set to review the floor system with the beams and slab engaged,” said Barnes.

Barnes also shared similar benefits with concrete column design. “Tekla Structural Designer does grillage take-downs floor-by-floor, finds the reactions and applies them to the next floor. This allows us to view column results both for the 3-dimensional effects of the structure as a whole and from the more traditional floor-by-floor load take-down point of view.

Doing both has always required significant manual intervention, but Tekla Structural Designer puts it all in one place.” “We reduce the possibility for human error because with Tekla Structural Designer less user input is required,” said Barnes. “Tekla Structural Designer automatically computes many of the design parameters, such as column unbraced lengths. The assumptions made by the software are typically correct, but we can easily review and override them when necessary.”

“Tekla Structural Designer provided the best fit for our workflow compared to other commercially available software.”

Want to Evaluate Tekla Structural Designer? tekla.com/TryTekla

CONTENTS Columns and Departments

Cover Feature

BUILDING BLOCKS

20 High-Volume SCM Grouts for Masonry

By Jamie Farny

EDITORIAL

5 Much Will Be Expected

By Thomas A. Grogan, P.E., S.E.

CODE UPDATES

22 TMS 402/602-16

By Richard Bennett, Ph.D., P.E.

STRUCTURAL PERFORMANCE

7 Tornado Debris Impact Testing and Masonry

By Diane B. Throop, P.E., W. Mark McGinley, Ph.D., P.E., and William L. Coulbourne, P.E., SECB

User-Friendly Tables

By Charles Haynes, P.E.

INSIGHTS

67 The Use of Fiber Reinforced Polymer

By John Masek, P.E., S.E.,

STRUCTURAL REHABILITATION

10 Terra Cotta Clad Steel Frame Building Repair Approach

By Gina Crevello and

and Briant Jacobs, P.E.

26 RESTORING HISTORY

By John Grill, P.E., and Rex Cyphers, P.E.

SPOTLIGHT

St. Francis of Assisi Catholic Church, an English Gothic-style

74 Riverfront Revival

structure (circa 1895), recently completed its restoration. Using

By Paul Evans

the best of old and new methods allowed the team to improve

Michelle K. Perez

and restore this 100-plus-year-old façade.

STRUCTURAL FORUM STRUCTURAL SYSTEMS

14 So, You Need to Design a Masonry Infill…

75 Licensure of Structural Engineers

By Edward Major II, E.I.T.

By Charles J. Tucker, P.E., Ph.D.

STRUCTURAL DESIGN

17 Transverse (Confinement) Reinforcement

By Edwin T. Huston, P.E., S.E., and Thomas Young, P.E.

IN EVERY ISSUE 6 Advertiser Index 66 Resource Guide – Steel/CFS 68 NCSEA News 70 SEI Structural Columns 72 CASE in Point

28 SPECIAL SECTION

S T R U C T U R E solutions

Profiling STRUCTURE’s advertising partners – an in-depth look at products and services.

Publication of any article, image, or advertisement in STRUCTURE® magazine does not constitute endorsement by NCSEA, CASE, SEI, the Publisher, or the Editorial Board. Authors, contributors, and advertisers retain sole responsibility for the content of their submissions.

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Editorial

Much Will Be Expected Thomas A. Grogan Jr., P.E., S.E., F.ASCE, NCSEA Past President

A

s I enter the latter phases of my career, I reflect on changes in how structural design documents are developed, recorded, and used for facilities and bridges around the globe. I am a Baby Boomer, so the only constant in my career has been change.

When I first started, we produced drawings on mylar and specifications using a typewriter; there were no electronics involved. We moved from the slide rule to calculators early in my career and ran structural software utilizing punch cards and mainframe computers. I remember when we did preliminary and final analysis using the portal frame and moment distribution techniques. Companies had a computer room where one went to run an analysis. I still remember doing building additions and renovations where the original drawings were on linen; those documents were works of art. Everyone had a drafting board with a T-square, triangles, electric erasers, and erasing shields.

As my career progressed, personal computers came into vogue, and word processors and spreadsheets became the new normal. You could now do all your work at your desk. Can you remember C:>, WordPerfect, MultiMate, and Lotus 123? How about Intel i186, i286, i386, and i486 microprocessors, and finally the Pentium? We had 13-inch screens with green characters, followed by an amber monitor which was so much easier on the eyes. Then one day we woke up and the Windows operating system was born, with colors everywhere! You could have two programs open at the same time.

Monitors gradually became larger and flatter, and today most of us use two or three that are 24-inch or larger.

around, and our phones were hardwired. It feels like just yesterday the mobile phone and laptop computer became the new normal, and suddenly we could work from anywhere. Fortunately – or unfortunately, depending on your viewpoint – we were connected 24/7.

I remember telling my wife that I never wanted to be that connected to work and now, 20 years later it seems as if we all work around the clock. I am not so sure that this is a good thing.

For better or for worse, those who embrace change will reap the rewards. One question we must ask ourselves, has all this made our profession better? I think that the answer is a resounding yes – our analysis tools are much better and how we document our work is more accurate. The different disciplines share the same layers, which reduces drawing errors, and many of our analysis software results can be imported directly into our documents. We even have clash detection to ensure that the different building systems will fit within the same space.

We are producing work at lightning speeds – but are we spending adequate time reviewing it? Here is where I think we need to focus significantly more effort. With ever shorter deadlines, we sometimes forget the adage that an ounce of prevention is worth a pound of cure. How often – be honest – have you seen a set of drawings go out without a thorough review? I am not talking about a senior engineer spending an hour or two, but someone spending a day or two reviewing the plans, details, calculations, and specifications. Those reviewers are checking the design and coordination, not only within the structural drawings but also with the rest of the project documents.

At the beginning of my career, this was the norm; now it happens far less frequently. In many cases, that decision is controlled by the financial condition of the project. As professionals, we are mandated to protect the health, safety, and welfare of the public. While we do this well, I believe that document review is our most significant opportunity for improvement.

Years ago, it was easy to spot the places on design drawings to look more closely – wherever the mylar was most smudged or had lost its film because of various revisions. Now, when we plot electronic drawings, they all look so good that it is much tougher to spot problem areas – it requires the expertise of a seasoned structural engineer. How about specifications – does anyone do more than a cursory review of those these days? Without thorough coordination with the drawings, we could be adding unnecessary cost and schedule impacts or, worse yet, miss something that could negatively impact the design integrity of the structure.

Let me encourage all of us to take a few minutes to evaluate how we review our work to ensure that what we produce truly represents the quality level we intend. This is an awesome profession that has grown much over the years. As the saying goes, from those to whom much has been given, much will be expected. We need to make sure that we do not lose focus on design quality by relying too much on the technology that has significantly improved how we perform our work.▪

With all this new technology came changes in how we documented our work. AutoCAD became the new normal. How awesome was it that we could put our drawings together electronically and plot them without those terrible smelling ammonia printers? Remember drum plotters with multiple pens of different line weights? Those drum plotters gave way to sheet plotters, which gave way to today’s plotters that work like a copier.

As this was happening, how we communicated changed from letters and telephone calls to e-mails. Next came text messaging, followed by social media: Facebook, LinkedIn, Twitter, Instagram, and now Snapchat. It seemed we suddenly started talking to each other less and less. It was much easier to communicate with many people using one of these media options than to pick up the phone to say hello.

The next transformation was mobility. Up to this point, all work was done at the office; we could not very well carry our bulky PCs STRUCTURE magazine

Thomas A. Grogan Jr. is Chief Structural Engineer and Director of Quality at The Haskell Company in Jacksonville, FL. He is also a member of the NCSEA Licensure Committee and past president of NCSEA and FSEA. Tom may be contacted via email at thomas.grogan@haskell.com.

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May 2018

ADVERTISER INDEX

PLEASE SUPPORT THESE ADVERTISERS

American Concrete Institute .............. 50-51 Larsen Products Corp. ..............................59 Anthony Forest.........................................37 MacLean Power Systems...........................23 Cast Connex .................................. 2, 46-47 MAPEI Corp...................................... 34-35 Clark Dietrich Building Systems ........ 32-33 NCEES ....................................................29 CTP Inc. .................................................18 Nordic Structures .....................................63 Dayton Superior Corporation ..................62 Nucor Vulcraft Group ........................ 42-43 Design Data .............................................13 RISA ............................................ 64-65, 76 Dlubal Software, Inc. ........................ 52-53 Simpson Strong-Tie................. 30-31, 56-57 Geopier Foundation Company.................36 Strongwell .......................................... 48-49 GRM Custom Products ...........................60 StructurePoint .................................... 38-39 Hohmann & Barnard, Inc. ......................44 Struware, Inc. ...........................................66 Independence Tube Corporation ..............25 Taylor Devices, Inc. ..................................58 Integrity Software, Inc. ..............................6 Trimble ......................................................3 ITT Enidine Inc. ......................................61 USG Corporation .............................. 40-41 Kinemetrics ..............................................54 Veit Christoph GmbH .............................45 KPFF .......................................................16 Williams Form Engineering .....................55 Erratum In STRUCTURE’s April 2018 Structural Design article, Design of Reinforced Concrete Diaphragms for Wind, one of the expressions should have been squared in the equation below.

The online version has been updated. w ( 21+ w2)(l1 + 12 + l3)2 = R l + R (l + 1 ) + R (l + 1 + l ) A 1 B 1 2 C 1 2 3 3

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Greg Schindler, P.E., S.E. Sammamish, WA Stephen P. Schneider, Ph.D., P.E., S.E. BergerABAM, Vancouver, WA John “Buddy” Showalter, P.E. American Wood Council, Leesburg, VA Diane Throop P.E. Masonry Industry Representative May 2018, Volume 25, Number 5 ISSN 1536-4283. Publications Agreement No. 40675118.

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T

hose of you who have had an opportunity to work in jurisdictions that have adopted the 2015 International Building Code (IBC) should have noticed a significant change related to mandatory tornado shelters in a significant portion of the Central U.S. For areas that use the 2015 IBC, this new requirement will impact the majority of new school and emergency facility construction spanning as far north as central Minnesota, as far south as southern Mississippi, and stretching to western Pennsylvania in the east and western Texas to the west. This area is shown in Figure 1 and is where tornadoes with wind speeds of at least 250 mph have a history of occurrence.

The IBC 2015 requires these tornado shelters be designed to meet the requirements of the 2014 ICC 500, Standard for the Design and Construction of Storm Shelters, and requires each shelter be designed to: 1) be tornado debris impact resistant, 2) resist wind speeds up to 250 mph, 3) accommodate all the building occupants, and 4) meet other requirements described in the ICC 500.

Impact Testing Many schools and emergency facilities are constructed using masonry. This type of construction can be used to provide a safe, practical, and costeffective solution for sheltering from tornados and high wind events. Therefore, it is important to understand what masonry wall configurations can be used to meet the required debris impact test for tornado shelters. It is imperative to note that all portions of the exterior envelope of tornado shelters must be able to meet the tornado

debris impact test defined in the ICC 500 document and that these are more stringent than the requirements for hurricane impact testing.

As described in ICC 500, the exterior walls of all tornado shelters (of all material types) must be able to withstand three test “missile” impacts without penetration of the interior surface of the wall. The prescribed 2x4 wood missiles are 15 pounds in weight and are launched so that they are traveling at a minimum of 100 mph when they impact the wall segment being tested (Figure 2, page 8).

structural

PERFORMANCE

Tornado Debris Impact Testing and Masonry Prior to 2014, only solidly grouted, singlewythe masonry walls systems were known to pass the tornado debris impact test. Designers had the option to use a single-wythe, solidly grouted wall, with or without a veneer. The expectation was the veneer, if used, would not contribute to the impact resistance and would be stripped away during the high wind event. In 2014, however, additional testing was done on partially grouted, cavity wall systems utilizing both the backup wall and the veneer to resist the missile impact. These tests opened additional masonry wall configurations for use in tornado sheltering applications.

New Testing Because schools and emergency facilities frequently use partially grouted, masonry cavity walls (especially in the regions encompassing most of the ICC 500's – 250 mph wind zone), questions were raised as to whether a masonry cavity could provide sufficient debris resistance,

By Diane B. Throop, P.E., FASTM, FTMS, W. Mark McGinley, Ph.D., P.E., FASTM, and William L. Coulbourne, P.E., F.SEI, F.ASCE, SECB Diane B. Throop is the Founder and head of her consulting firm. She served as the Chair of the 2013 and the 2011 Masonry Standards Joint Committee (MSJC). She currently serves as the Chair of the 2022 TMS 402/TMS 602 General Requirements Subcommittee Chair (formerly the MSJC) and is currently active on the ASCE Wind Speed Estimation in Tornados Committee and the NCSEA Wind Committee W. Mark McGinley is Professor and Endowed Chair for Infrastructure Research, Civil and Environmental Engineering, J.B. Speed School of Engineering, University of Louisville. Dr. McGinley currently is Chair of the Flexure, Axial & Shear Subcommittee of the TMS 402/ TMS 602 Building Code Requirements and Specification for Masonry Committee (formerly the MSJC). He has been a primary author of all 7 editions of the TMS Masonry Designers Guide.

Bill Coulbourne is a national expert in wind and flood mitigation and has been involved in FEMA Mitigation Assessment Teams for over 15 years.

Figure 1. 250 MPH (402 Km/hr) tornado shelter zone per ICC 500-2014.

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Figure 2. Tornado missile testing cannon.

even if the backing wall was not fully grouted.

A testing program was developed and executed as described below to answer the question.

Several questions needed to be addressed to arrive at a reasonable number of test specimens to prove the theory that partially reinforced and grouted CMU could effectively resist tornado missiles when covered with a brick veneer.

1) Would the size of the brick veneer units influence impact resistance?

2) Would a veneer of smaller units and more mortar joints behave differently than one with larger units and less mortar?

3) As both modular and utility size brick units are commonly used for school cavity wall construction, these were tested to determine if the face size of the veneer unit and corresponding amount of mortar joints mattered.

4) Would the reinforcing configuration of the partially reinforced CMU backup wall influence impact resistance?

5) Would a closer spacing of the reinforced and grouted sections of wall influence impact resistances?

6) As it is highly unlikely that a partially grouted CMU wall reinforced at vertical spacings of more than 32 inches would be able to resist the mandated ICC 500 tornado wind pressures, one of the test specimens used this reinforcing spacing in its backup wall. The second test specimen used a 24-inch-on-center backup wall reinforcing spacing if the larger spacing did not pass.

Cavity Wall Systems Tested Two different wall configurations were developed and designed to be representative of clay brick and CMU cavity walls used in conventional exterior walls for schools. Figure 3 shows the first configuration. This wall specimen is consistent with common exterior school wall designs, with utility-size clay brick veneer, a

2-inch cavity, and noted. Two additional missiles were fired at an 8-inch partially this specimen; one missile was directed to grouted CMU the lower outer edge of the vertically grouted backup wall. The CMU cores on the right side of the speciCMU backup wall men, and one missile was directed to the was reinforced verti- inner edge of the vertically grouted CMU cally with #5, 60 ksi cores on the left side of the specimen. Similar rebar, at 32 inches behavior was observed in all the impacts on-center. There was – the missile shattering the brick, pushing a bond beam cast at the brick pieces against the CMU face, and the top of the wall rebounding without causing any damage to specimen to tie the the CMU wall. In all three tests, brick veneer specimen together. A was damaged (but repairable) and there was heavy duty, 3⁄16-inch- no visible damage to the CMU backup wall. diameter eye-and-pintel anchor system was Furthermore, upon careful inspection, there used to attach the brick veneer to the backup was no visible cracking or no missile penetrawall; these anchors were spaced at 16 inches tion of the interior face of the CMU wall. both vertically and horizontally. The specimens The above tests were repeated for Cavity were constructed using ASTM C 90 CMU Wall Specimen 2 (modular clay brick veneer units, ASTM C 216 clay units, and ASTM and closer spaced vertical reinforcement).

C 270 Type S Masonry Cement Mortar. Fine The results mirrored those of Cavity Wall grout was used, site-mixed based on the pro- Specimen 1. portion specification of ASTM C 476.

The results of these tests clearly show that Figure 4 shows the second specimen. the brick veneer absorbs a significant amount Recognizing that more than one parameter of the missile’s energy. The shattering of the was changing between the specimens, it clay brick unit, the presence of the air cavity was decided to change both brick size and between the veneer and backup wall, and the reinforcement spacing on each specimen to ductile failure of the 3⁄16-inch diameter wire gather the most information from this limited anchors reduced the backup wall strike energy testing. This specimen was configured the to levels low enough that the ungrouted same as the first, except that modular clay sections of the partially grouted CMU backup brick was used in the veneer and the vertical are able to resist the missile impact with no reinforcing spacing in the CMU backup wall visible interior damage (Figure 6). Thus, was reduced to 24 inches. the two brick-veneer and partially grouted Each of these specimens was tested at the CMU cavity wall configurations tested were Wind Testing Laboratory at Texas Tech deemed to have passed the code-mandated, University in Lubbock, Texas. The first tornado debris impact testing requirement. specimen was placed in a missile testing Even though the outer veneer is damaged in apparatus, and a total of three, 15-pound the location of impact, the missiles did not 2 x 4 wood debris missiles were fired at the penetrate to the interior face. It should be specimen at the prescribed speed required by noted that the veneer damage would be easily the ICC 500. repairable after the wind event.

The first missile strike was aimed at the middle of an ungrouted CMU core near mid-height and mid-width of the specimen.

Figure 5 shows that, upon impact, the 2 x 4 missile shattered the clay brick veneer units at the missile impact location, passed through the brick veneer, and bounced off the cavity-side surface of the CMU backup wall with no damage Figure 3. Cavity Wall Specimen 1 – utility brick.

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Figure 4. Cavity Wall Specimen 2 – modular brick.

noted that the veneer damage would be easily repairable after the wind event.

The behavior of the cavity wall contrasts that of a single wythe masonry wall where the masonry must be grouted solid to provide this same level of missile impact resistance Masonry Options Solidly Grouted, Single Wythe Walls – To be missile impact resistant, singlewythe, solidly grouted systems must be constructed of concrete masonry units that meet ASTM C90, be solidly grouted with vertical reinforcement, and have a minimum thickness of 6 inches (reinforcement options vary). They may also be constructed of clay brick units that meet ASTM C216 or C652, be solidly grouted with vertical reinforcement and have a minimum thickness of 6 inches (reinforcement options vary).

Partially Grouted Cavity Walls – To be missile impact resistant, double-wythe masonry cavity wall systems must be constructed with a backup wall built of CMU that meet ASTM C90 (minimum thickness of

Figure 5. A first missile strike on Cavity Wall Specimen 1.

8 inches), are partially grouted and vertically reinforced at a maximum spacing of 32 inches on-center horizontally with a veneer of utilitysized clay brick units meeting ASTM C216 (4-inch minimum nominal thickness), and anchored per the test configuration described above. Ties must be engineered to withstand the wind speeds prescribed by ICC 500 to prevent the veneer from being stripped away during the tornado. As an alternative, modular size clay brick units meeting ASTM C216 (4-inch minimum nominal thickness) can be used for the veneer.

Shelter Design

While this article primarily describes the tornado debris impact testing of masonry wall systems, it seems prudent to discuss the implications of shelter designs using exterior masonry wall systems. ICC 500 states that, when sheltering is mandated, a set of design requirements must be met. These provisions include structural, civil, and architectural requirements, along with increased documentation and inspection. As an example, tornado shelters must provide a minimum 5-square-feet of usable floor area per building occupant, minimum ventilation, sanitary facilities, fenestration impact resistance, handicap access, and minimum egress requirements.

Structurally, the exterior walls of the shelter and the roof must pass debris impact tests and be designed to resist wind pressures from 250 mph wind events (in addition to the other design loads that are typically much less).

Shelter roofs and walls must also be designed to resist a 100 psf minimum Figure 6. CMU surface behind missile strike on the Utility roof live load. (Note – this is not an Unit Specimen 1 after testing.

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inclusive list of requirements for shelter design, just an overview).

A comparison of typical exterior masonry wall designs, first acting as a shelter wall and second not acting as a shelter, shows that the shelter walls would require an increase in bar size from a #5 bar to a # 6 bar with a decrease in spacing from 64 inches on-center to 24 inches on-center. This design comparison was based on typical State of Ohio design conditions and typical wall geometries.

The results of the missile tests indicated that some partially grouted brick veneer cavity walls could also be used as the exterior shelter walls. For this type of wall, the reinforcing of the CMU backup would be the same, but the backup wall would not have to be fully grouted (a significant consideration for seismic loading and thermal resistance). If partially grouted cavity walls are used, the veneer anchor systems must be engineered for the wind loading produced by 250 mph winds.

Analysis of the typical CMU backed veneer and anchors suggest that a heavy-duty version of typical anchor systems would be adequate for this application.

Conclusions The results of the impact tests show that masonry cavity walls of brick veneer and partially grouted and reinforced CMU backup walls can provide sufficient tornado debris resistance to be considered for exterior shelter walls without the need for solid grouting.

Masonry walls can be used to provide safe, practical and cost-effective solutions for sheltering from tornados and high wind events. Moreover, now, there are options for both solidly grouted and partially grouted masonry shelter walls.▪

structural

REHABILITATION

T

he case to replace terra cotta in-kind with the integration of a corrosion mitigation system, rather than full-scale replacement or replacement with an imitation material, provides clients with a durable, long-term repair and restoration program that retains the original building fabric. This article discusses the history of architectural terra cotta and various repair options in lieu of stripping and replacing.

History and Use Architectural terra cotta is one of the most beautiful, flexible, weather resistant building materials and can last thousands of years.

Archaeological discoveries of terra cotta, or “baked earth,” date back to 3000 BCE. Its first use as a structural building material has been recorded in Italy in the 15th century.

In America, the primary use of Architectural terra cotta in urban centers began in the 1850s and continued to soar throughout the early 20th century.

America was growing by leaps and bounds, adding roughly 35,000,000 immigrants to our nation from 1850 to 1930. Innovations like the elevator, initially invented in 1852, advancements in foundation engineering, and the use of steel frame construction helped to build beyond the typical 5-story walk up. Construction advancements were accommodating the flood of people into our bulging cities.

The new American Bourgeoisie, returning home from their “Grand Tours,” applied a newly learned artistic expression, influenced by the antiquities they discovered throughout Europe, to their corporate headquarters, residential towers, and the hotels ornamenting city skylines. The leading architects of the time, Richard Morris Hunt and H.H. Richardson, both studied at the L’Ecole des Beaux-Arts in Paris. The school was renowned for its neo-classical approach to design.

Upon their return to the United States, Hunt’s and Richardson’s work influenced many leading American architects like Louis Sullivan, Daniel Burnham, and the battery of men who either followed or practiced directly under them.

As urban centers grew, earlier wood frame construction left cities like New York, Boston, Chicago, and San Francisco vulnerable to great fires. Prior to these fires, cast and wrought iron were employed in construction for use in some buildings dating back to 1793. After the great fires of the 1870s, the fireproof quality of steel and masonry construction was elevated.

This social, industrial, and disaster history led to a need for America’s growing, densely populated cities to have taller, fireproof buildings. The engineers and construction teams flexed their

Terra Cotta Clad Steel Frame Building Repair Approach Repair Options and Replacement Materials

By Gina Crevello and Michelle K. Perez

Gina Crevello is a Principal and Founder of Echem Consultants LLC. Ms. Crevello is on the Board of Directors for the Association of Preservation Technology and is active with the National Association of Corrosion Engineers and the International Concrete Repair Institute.

She may be reached at gcrevello@e2chem.com.

Michelle K. Perez is the Northeast Territory Manager for Gladding, McBean. Michelle has extensive knowledge of terra cotta’s historic use, current conditions, the effects alternative materials have on steel corrosion and further degradation to terra cotta, and alternative approaches to the building envelope preservation.

She can be reached at michelle.perez@gladdingmcbean.com.

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10 May 2018

muscles, and the steel industry responded with innovative new materials. As developments in the steel industry occurred, improvements were made to its quality, strength, and manufacturing processes. With steel possessing better tensile qualities, less weight than cast or wrought iron, and competitive manufacturing, it became integral to American construction technology. By 1880, American skyscrapers were self-supporting steel “cages” decorated with classical ornamentation.

It was not always practical or economical for the tall steel frames to support solid, hand-carved stone. Terra cotta was an excellent substitute.

Made of clay, its plasticity allowed it to be formed into any shape; the use of molds made it easier to mass produce high-quality beaux art design. Terra cotta units were hollow and significantly lighter than stone, and its compressive strength could support its own weight. Hence, a new non-load bearing enclosure for the metal skeletal structure, i.e., the curtain wall, was developed (Figure 1).

Historically, manufacturing methods were limited to hand pressing the clay into molds.

Though modern methods of manufacturing such as extrusion, RAM pressing (a machine used to press clay into molded shapes), and slip casting are employed today to expedite the manufacturing process, modern ornamental

Figure 1. The Reliance Building, Burnham and Root/ Atwood. Example of an early steel frame terra cotta clad building. Courtesy of TheArchitecturePost.com.

Figure 2. Terra cotta cornice spot replacement with ICCP in 2004. Two pieces of terra cotta were replaced on the full cornice, and the entire steel outrigger system is protected by Impressed Current Cathodic Protection.

architectural terra cotta still requires the touch of a classically trained sculptor or craftsperson.

In summary, terra cotta became an ideal building material because of its fireproof, light weight (lighter than cast stone), high compressive strength properties, and its ability to be easily molded and manufactured at a faster rate than stone could be carved. It could be used to mimic more expensive stone but became a creative tool for architectural expression in high-rise construction. The use of glazing allowed for a full-color range for material selection, further enhancing terra cotta’s versatility and waterproofing qualities.

Material Degradation With properties similar to brick, the combined use of brick infill and terra cotta cladding became standard in late 19th- and early 20th-century skyscraper design. Terra cotta and brick are both clay-based materials with grog (finely ground pre-fired ceramic) and are fired in a kiln at approximately 2000 degrees Fahrenheit. The materials are compatible and work harmoniously. Terra cotta is held in place to back up wall construction with metallic anchorage and clamps.

Construction detailing became standardized by the National Terra Cotta Society, first in 1914 and again in 1927. By 1927, further details were developed in relation to material performance, accounting for expansion of the terra cotta, structural failure, and water management within the building envelope.

Shelf supports, provisions for movement, freestanding construction, and flashing and drips were the most important principles upon which the standard was revised. It was also noted that “proper care should be exercised to prevent corrosion of all steel supports and ties. Where such protection cannot be permanently secured through mortar or concrete, or with corrosion resistant metallic coatings, non-corrosive metals should be employed.” While terra cotta was found to be a very durable building material, by

Figure 3. Discoloration of GFRC units used in conjunction with original terra cotta.

the 1920s, it was recognized that moisture and corrosion were deleterious agents which would impact material performance if not managed appropriately.

Deterioration Common modes of material failure for terra cotta include glaze and surface erosion, stress cracking from expansion, and deterioration caused by faulty craftsmanship. Most deleterious to the material is corrosion of the anchorage and steel frame. Other than craftsmanship defects, moisture ingress is a leading cause of the pervasive deterioration of terra cotta systems. Moisture penetrates the building system through failed joints, failed glazing, eroded surfaces caused by caustic cleaning or glaze degradation from atmospheric contaminants, or other waterproofing failures of the building envelope.

Moisture migration and movement through the building envelope of glazed terra cotta systems are prone to trapping moisture. This is due to the highly resistive and impermeable surface layer of the vitrified glaze, narrow mortar joints between units, and lack of weeps within the assembly. The material properties of the fired clay terra cotta body can retain moisture, keeping the infill and terra cotta unit damp. Retained moisture can lead to glaze spalling, cyclic freeze/thaw issues, and corrosion of the reinforcing steel.

Moisture and oxygen in the building envelope will incite corrosion of the steel frame and anchorage. This, in turn, cracks the masonry.

As the cracks open, more oxygen and airborne particulates can reach the embedded steel.

This increases rates of oxidation. Cracking caused by the accumulation of corrosion scale can destabilize terra cotta to the point of failure, leading to spalls and falling units.

Repair Options Cracked and unsafe terra cotta units require replacement. Traditional repair options can be

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costly and disruptive to the building envelope.

This entails stripping the terra cotta from the building to expose the frame and painting or waterproofing the steel. Where steel repairs are required, however, the frame itself must be accessed. After stripping and reinstating the masonry, repointing and waterproofing of the envelope are carried out. When making large-scale replacements, it is estimated that up to 30% of the surrounding material will be damaged by the repair. Often, spot replacement is performed instead of large-scale stripping due to cost and disruption to the building. If corrosion is left unmitigated, further damages will arise quickly in adjacent areas.

Replacement in-kind is always the preferable repair option when approaching a historic restoration, for landmark compliance, material compatibility, and durability. Spot repairs and alternate materials have been utilized in the recent past to reduce repair expenditures for full-scale terra cotta replacement.

Spot Replacement and ICCP When conditions allow, a spot replacement program with terra cotta and an integrated impressed current cathodic protection system (ICCP) can provide a 25+ year repair. These systems control corrosion of the embedded steel, not surface erosion of terra cotta. ICCP systems are low-voltage DC systems that provide electrons to the steel from an external anode.

This process controls the corrosion reactions.

All the embedded steel becomes “cathodic” or protected. The systems are installed in the mortar joints and backup masonry material, and are then painted over. This allows for the original material to remain in place, while mitigating corrosion, and only requires “unsafe” cracked or damaged terra cotta units to be removed and replaced. These systems have been successfully used since 1991 in historic restorations. Aside from being sympathetic to the historical integrity of the structure, they ensure that future damages to the building envelope by corrosion are addressed (Figure 2). continued on next page

scheduling concern. When an owner pushes back on these factors, teams often consider alternative materials for wholesale replacement. Although schedule may be slightly shorter, costs to the building, both initial and long-term, are not proven.

Methods such as reduced terra cotta in-kind replacement (replacing only pieces with visible cracks) along with cathodic Figure 4. a) Full cornice replacement with GFRC. Note shrinking of sealant, opening Figure 5. Cast stone at winter protection offer cost savings to owners of joints, water infiltration, and subsequent calcium leaching; b) Detail. lintel suffering from corrosion. and provide the historic building with a long-term solution that honors its historic with inorganic aggregates; the polymer integrity. These systems are sympathetic to the Alternative Repair Materials replaces the lime or cement-based binder. building envelope in that no signs of the system The use of alternative materials on terra cotta These materials have significantly different are visible from the exterior, only the conduit restoration projects has increasingly grown performance attributes when compared to and DC power supplies. since the 1980s. Materials such as GFRC (glass terra cotta. They are lightweight and nonWhen looking for a long-term durable repair fiber reinforced concrete), FRP (fiber rein- structural in nature and are suitable to be for deteriorated terra cotta, terra cotta itself forced plastic), cast stone units, and concrete suspended from anchorage or installed in must be considered the first option when resins are utilized. While these materials may a decorative capacity. Concerns regarding replacing deficient material. When minimizhave successful applications as independent the flammability of earlier systems led to ing replacement pieces, spot replacement building systems, their use as an alternative to the development of newer mix designs to in-kind with cathodic protection will offer a terra cotta warrants on-going evaluation. When meet ASTM E84, “Standard Test Method for 25+ year design. Overall, the long-term benefit considering these materials, it is essential to Surface Burning Characteristics of Building of spot-replacement allows for physical, chemiunderstand the basics of the material compo- Materials,” criteria for flame resistance. cal, aesthetic, and material compatibility. Case nents, how they differ in manufacturing from Conventional wisdom is to replace in- studies demonstrating the success date back terra cotta, and ultimately their performance kind; when this cannot be done, limit the to the 1990s, with many American buildings once installed in buildings. replacement to spot areas. While this is a having been treated in this manner. The tarGFRC is comprised of glass fibers in a conventional approach, the spot replacement geted spot replacement allows for a reduced cementitious matrix. During manufacturing, using alternative materials will create a “Catch expenditure on terra cotta which minimizes the material is spray applied into molds, and 22” situation. Whenever dissimilar materi- corrosion damage to the façade, limits liabilities then a hand roller is used to bond the layers als are adjacent to one another, the stresses and reduces the risks of falling masonry.▪ together. GFRC is not kiln fired; instead, it is of the stronger material will be born upon cured for 24 hours to seven days depending on the weaker material. The use of replacement The online version of this article the manufacturer. GFRC is typically in molded materials should consider that the comprescontains references. Please visit panels, which allows for numerous repetitive sive strength, modulus of elasticity, coefficient www.STRUCTUREmag.org. masonry courses to be replicated in one piece of thermal expansion and contraction, water and supported by hangers (i.e., cornices). absorption, and ultraviolet stability will all FRP is formed by pouring a polyester or resin differ. Often dissimilar materials do not bond into a mold. After this, tack-free layers of glass equally and can allow water to seep into the fabric are added with additional coats of resin. structure, causing further damage. Therefore, These are more lightweight than GFRC and, it is important to recognize the common as non-loadbearing components, are used for alternative materials that are dissimilar to lightweight elements in a building. terra cotta, manufactured differently, and Cast Stone is comprised of a mixture of ultimately perform differently once installed cements, aggregates, and mineral pigments within the building envelope and wall system. using either a dry tamp or a wet cast process.

The observed performance of alternative Cast stone is not kiln fired; it is cured for systems has been documented with a select approximately five days in various degrees number of cases presented here (Figures 3-6 ). of dampness. Like terra cotta, cast stone has The defects illustrate material incompatibilities been used as a decorative element in construc- between existing terra cotta and new materials tion. Cast stone units often replace surface and are not a critique of alternative materials stone and ornamental features. All cementi- on their own. tious materials will shrink in service, thereby pulling the mortar joints into tension. To Conclusions mitigate mortar cracking, control joints are incorporated, and soft joints must be placed Wholesale replacement is often considered between the dissimilar materials. the only alternative for terra cotta repair.

Concrete resins, or polymer concretes, Wholesale replacement can be costly and Figure 6. Full wall replacement cast stone units. are comprised of synthetic polymer resins disruptive to the tenants and can be a Note the shrinkage, water infiltration, and leaching. a)

b)

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structural

SYSTEMS

Y

our client has proposed a building where the exterior steel beams and columns are painted and exposed but the portal space is filled with concrete masonry. Your first thought may be, “Wow, that is a lot of extra building mass to deal with!” Immediately after that thought might come a series of questions. “I wonder if there is a way to use that masonry, instead of it just being along for the ride? Where would I look for design guidance?” The short answers to those questions are yes, you can make use of the masonry and answers are available in the Building Code Requirements for Masonry Structures (TMS 402). This article expands on those answers and additional questions that might arise during the design process.

So, You Need to Design a Masonry Infill…

By Charles J. Tucker, P.E., Ph.D.

Charles Tucker teaches basic engineering courses at FreedHardeman University and serves as the Partitions and Infills Subcommittee Chair for TMS 402/602. He may be reached at ctucker@fhu.edu.

Infill Behavior The proposed system is specifically called a masonry infilled frame, and they are far from new. Thousands of masonry infilled frames have been constructed in the United States and internationally over the last century. Unfortunately, many of those designs did not take into consideration the complexity of the behavior of the masonry when it is bounded by an external frame. First, it would be wise to explore the behavior of masonry infills as they are loaded with in-plane forces.

Several stages of response occur during the inplane loading of a masonry infilled frame. Initially, the system acts as a monolithic cantilever wall.

Figure 1. Equivalent strut.

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Slight stress concentrations occur at the four corners, while the middle of the panel develops an approximately pure shear stress state. As in-plane loading continues, separation occurs at the interface of the masonry and the frame members at the off-diagonal corners. Once a gap is formed, the stresses at the tensile corners are relieved while those near the compressive corners are increased.

As the load continues to increase, further separation between the masonry panel and the frame occurs, resulting in contact only at the frame sections near the loaded corners. This condition of contact results in the composite system behaving as a braced frame. This has led to the concept of replacing the masonry infill with an equivalent diagonal strut when modeling the behavior of the system (Figure 1; gaps are highly exaggerated). The induced stresses in the masonry panel produce various cracking patterns depending on the combination of the shear strength of the mortar joints, the tensile strength of the masonry units, and the relative values of the shear and normal stresses.

Failure of masonry infilled frames can be classified into three basic modes: shear cracking, compression failure, and flexural cracking. Shear cracking can be divided into cracking along the mortar joints, which includes stepped cracks and horizontal cracks, and diagonal tensile cracking.

The compression failure mode consists of the crushing of the masonry in the loaded diagonal corners and the failure of the diagonal strut. The diagonal strut is developed within the panel as a result of diagonal tensile cracking. Flexural cracking failure is rare because separation at the masonry-frame interface usually occurs first; then, the lateral force is resisted by the truss

mechanism of the diagonal strut. Figure 2 shows the development of the diagonal strut using stepped loads in an ANSYS fi nite element analysis investigation. The upper left corner is the application point for the in-plane load with the load increasing from top to bottom in Figure 2. Note that the compressive stresses propagate from the loaded corner to the opposite diagonal corner. As the loading level increases, the compressive stresses in the confined corners also increase.

When loaded out-of-plane, masonry infills develop a three-hinged arch, which resists these out-of-plane loads. Figure 3 shows the development of such an arch. Small gaps (exaggerated in Figure 3) form on the loaded side of the infill between the infill and the bounding frame. Tensile stresses on the opposite face of the masonry cause a longitudinal crack to develop. The out-of-plane load is then resisted by compression in the masonry at the hinge locations. It should be noted that this arching can, and often does, develop as two-way arching. The Code equations presented later are based on two-way arching of the masonry infill material.

TMS 402 Design Guidance The 2011 TMS 402 added Appendix B, “Design of Masonry Infill,” to provide mandatory language to allow the designer to use masonry infill effectively. The 2013 and 2016 TMS 402 further developed those code provisions. These provisions address participating infills and non-participating infills for both in-plane and out-of-plane loading conditions, as well as limitations to the usage of masonry infills. Concrete masonry, clay masonry, and AAC masonry are all permitted as infills. Non-participating infills are required to be isolated from the surrounding frame, so as not to impart additional loads to the frame members that might cause localized failure to occur. For instance, infills that do not extend the full height of the column are prohibited from use as part of the lateral-force-resisting system due to the creation of short columns, which have historically performed poorly in seismic events. Currently, infills with openings are also prohibited; however, the current TMS 402 committee is considering code language to address small openings and their effect on the behavior of the infilled frame system.

TMS 402 Section B.3.5 also gives direction for the design of the bounding frame members. The bounding frame is obviously designed using the appropriate material code; however, TMS 402 recommends a ten percent increase in the design shear and moment loads established from the equivalent strut bracedframe analysis.

Design Example Consider a masonry infilled frame with the following properties. The infill is constructed of nominal 8-inch concrete masonry units, f´m = 2,000 psi, and Type S PCL mortar. Assume hollow units with face-shell bedding only (mortar on the face shells of the units only).

The total wall height measures 14 feet 10 inches to the roof, with the infill 14 feet in height.

The bounding columns are W10x45s oriented with the weak axis in the plane of the infill (Ibc = 53.4 in.4 weak axis and Ibc = 248 in.4 strong axis) and are spaced at 32 feet. The bounding beam above the masonry infill is a W10x39 (Ibb = 209 in.4 weak axis and Ibb = 45 in.4 strong axis) and carries only minimal roof loads. The infill is mortared tight to the bounding frame on all sides. The infilled frame is loaded with a wind load of 35 psf calculated per ASCE 7-10 with a 20-foot tributary area, resulting in a total unfactored in-plane load of 5,191 pounds.

Using the conservative loading case of 0.9D + 1.0W leaves the in-plane load at 5,191 pounds.

In-plane Design Section B.3.1.1 limits the nominal height-tothickness ratio to 30. The ratio for this infill is: hinf 168in. tinf = 8in. = 22.0

Figure 2. Strut development as load increases.

The height-to-thickness ratio is less than the maximum of 30 and is therefore accepted as a participating infill.

Calculation of the equivalent strut width is carried out using TMS 402 Equations B-1 and B-2a for concrete masonry and clay masonry, and TMS 402 Equation B-2b for AAC masonry.

0.3 winf = λstrut cosθstrut where

Emtnet inf sin2θstrut 4Ebc Ibc hinf √ The characteristic stiffness parameter, λstrut, is a measure of the relative stiffness of the bounding frame and the masonry infill. θstrut is the angle of the diagonal of the infill measured with respect to the horizontal, which is 23.6° for this infill. The net thickness of the infill, tnet inf , is 2.5 inches for this ungrouted infill. The characteristic stiffness parameter is then: λstrut =

4

λstrut = (1,800,000 psi)(2.5 in.)(sin(2)(23.6°)) 4 √ (4)(29,000,000psi)(53.4in. )(168in.) = 0.0422in.-1 4

The equivalent strut width is then: 0.3 = 7.8in. winf = (0.0422in.-1)(cos23.6°)

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Figure 3. One-way arching of infill.

TMS 402 Section B.3.4.3 states that the nominal shear strength of the infill shall be the least of Equation B-3, the horizontal component of the force in the equivalent strut at a horizontal racking displacement of 1.0 inch, or the smallest nominal shear strength from TMS Section 9.2.6.1 calculated along a bed joint. TMS 402 Equation B-3 is an empirical equation developed by Flanagan and Bennett in the late 1990s: Vn = ((6.0in.)tnet inf )f ´m TMS Equation B-4 and Section 11.2.5 are used when the infill is composed of AAC masonry. For this example, Vn (based on TMS 402 Equation B-3) is: Vn = (6.0in.)(2.5in.)(2,000psi ) = 30,000lb The stiffness of the equivalent braced frame is determined by a simple braced frame analysis where the stiffness is based on the elastic shortening of the diagonal strut. The strut area is taken as the width of the strut multiplied by the net thickness of the infill.

The equivalent braced frame stiffness is: 2 stiffness = AE cos θ d

where d is the diagonal length of the infill.

For this infilled frame the stiffness is:

stiffness = (7.8in.)(2.5in.)(1,800,000psi)(cos 2 (23.6°)) 419in. = 70,340 lb/in At a horizontal racking of 1.0 inch, the nominal shear strength is the stiffness multiplied by 1 inch and is thus 70,340 pounds.

The applicable sections of TMS 402 Section 9.2.6.1 are Equations a, b, and c. These yield nominal shear values of 163,144 pounds, 288,000 pounds, and 53,760 pounds, respectively, where the compressive force normal to the shear surface was conservatively taken as zero.

The least of these nominal shear values is 30,000 pounds from TMS 402 Equation B-3. Using the strength-reduction factor of 0.6, as mandated by TMS 402 Section B.1.4, results in a design shear capacity of 18,000 pounds, which significantly exceeds the factored design shear of 5,191 pounds and the infill is satisfactory for shear. As previously mentioned, TMS 402 Section B.3.5 requires the designer to consider the effect of the infill on the bounding frame and to increase the shear and moment results from the braced frame analysis by ten percent.

Out-of-plane Design TMS 402 Section B.3.6 provides equations for the nominal out-of-plane flexural capacity.

TMS 402 Equation B-5a requires that the flexural capacity of the infill be: αarch βarch qn inf =105(f´m)0.75t 2inf 2.5 + 2.5 l inf h inf where: 2 0.25 ) < 35 αarch = 1 (EbcIbc h inf hinf

)

(

2 0.25 βarch = 1 (Ebb Ibb l inf ) < 35 linf

If a side gap is present, αarch is taken as zero, while a top gap requires βarch to be taken as zero. In addition, tinf shall not be taken greater than 1/8hinf . TMS 402 Equation B-5b is used for AAC masonry infill. For the example infill: αarch = 1 [(29,000,000psi)(248in.4)(168 in.)2 ]0.25 168in. = 22.5lb 0.25 < 35 βarch = 1 [(29,000,000psi)(45in.4)(384 in.)2 ]0.25 384in. = 9.7lb 0.25 < 35 therefore,

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qn inf = (105)(2000psi)0.75(7.63in.)2 22.5lb 0.25 9.7lb 0.25 = 62.7psf + (384in.)2.5 (168in.)2.5

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Again, using the strength-reduction factor of 0.6 from TMS 402 Section B.1.4, results in a design flexural capacity of 37.6 psf, which exceeds the factored design wind load pressure of 35 psf and the infill is satisfactory for out-of-plane flexure.

Conclusion

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Masonry infills are an efficient structural system for resisting lateral loads. Their construction is simple; the bounding frame is erected first, then the portal space is infilled with masonry resulting in a composite system. This allows for a staged, but rapid, construction sequence. As seen in the design example, masonry infills are capable of withstanding significant loads. So, when your client suggests a masonry infilled frame, you can be ready to take on this design challenge. Be sure to take advantage of the inherent strength of masonry, refer to TMS 402 often, and happy infilling!▪

M

ost designers who engineer reinforced masonry know that code provisions for lap splice lengths have been evolving over the past few code editions. A newer confinement-steel option is available that has the potential to significantly reduce the lap splice lengths, especially for larger diameter bars, through confinement of the structural reinforcement.

Lap Splices and Constructability

confinement steel option described in this article, the horizontal bond beam steel may be used as confinement steel and can reduce the lap splice length required in the vertical reinforcement.

Lap Splices and the Codes

structural

DESIGN

As wall heights, wind pressures, or seismic forces increase, larger reinforcing bars are required and larger bars require longer laps. When walls are taller in areas of higher wind and seismic forces, bars may also need to be offset from the centerline of the wall to increase the internal moment arm between the tension and compression forces. In some cases, this can significantly increase lap splice lengths and impact constructability.

Reinforced masonry typically has vertical bars cast in grouted cells and may have horizontal bars cast in bond beams or joint reinforcement placed in mortar bed joints. In reinforced concrete masonry walls, long vertical bars are problematic for masons if traditional closed-end blocks are used. The mason must lift the blocks over the bar that extends out of the previously grouted masonry, or over dowels extending out of the footing.

The use of lap splices improves the constructability of walls when using traditional, closed-end The reinforced masonry design provisions found block (Figure 1). Lap splices allow the use of in the 2015 International Building Code (2015 shorter vertical bars by transferring stresses from IBC) reference the Building Code Requirements one reinforcing bar to another through the devel- and Specification for Masonry Structures, TMS opment of the splice. However, lap splices increase 402-13/ACI 530-13/ASCE 5-13 (TMS 402-13). the total volume of reinforcement in a wall and The reinforced masonry design provisions found can impact the cost of the project. Masonry con- in the 2018 International Building Code (2018 tractors have estimated that 80% of laps occur IBC) reference the Building Code Requirements at vertical bars. This is because long horizontal and Specification for Masonry Structures, TMS bars can be easily placed in bond beams with 402-16 (TMS 402-16). TMS 402-13 has lap minimal splicing. splice length equations for allowable stress The constructability of a masonry wall and the ease design (ASD) in Section 8.1.6 and lap splice of lap splicing is also impacted by the way the grout length equations for strength design (SD) in is placed. Walls can be grouted without clean-outs Section 9.3.3. In TMS 402-16, these provisions (typically called low-lift grouted) or grouted with have been harmonized between the two design cleanouts (high-lift grouted). In low-lift grouting, a methods and placed in Sections 6.1.5 and 6.1.6. short section of wall, up to 5 feet 4 inches high, is In either edition of the masonry standard, the laid up prior to grouting. The reinforcement being lap splice lengths calculated by these equations lap spliced extends above the section being grouted, depend on the specified steel reinforcement into the next section of wall to be constructed yield strength, the specified masonry compres(Figure 2, page 18 ). In high-lift grouting, the wall sive strength, reinforcement size factor, the bar can be laid to a maximum height of 24 feet prior diameter, and a bar location factor, K. The bar to grouting. In this case, longer vertical bars can location factor, K, is the smallest of the minibe placed before grouting and the number of lap mum cover, the clear spacing between adjacent splices is minimized. bar splices, or nine times the bar diameter. Since Horizontal reinforcing bars, placed in bond the bar location factor is in the denominator of beams, may limit which grouting method is uti- the lap splice length equations of the masonry lized due to grout flow concerns in partial-grouted standard, decreasing the bar location factor walls. However, bond beams are mandated for increases the lap length. For large bars placed areas of high seismicity and may be required for some designs in areas of low to moderate seismicity, especially if portions of the wall need to span horizontally. This may have the effect of negating the ability to use Figure 1. Concrete masonry units are manufactured with different web configurations. the higher grout pours. Closed-end units are most common, but open-end (“A”) or double open-end (“H”) units However, with the new are available in some areas.

Transverse (Confinement) Reinforcement

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May 2018

Optimizing Lap Splice Lengths of Masonry Reinforcement

By Edwin T. Huston, P.E., S.E., and Thomas Young, P.E. Edwin T. Huston is a Principal with the structural engineering firm of Smith & Huston Inc. in Seattle, WA. He has received numerous awards for his work and is a Past President of NCSEA. Thomas Young is the Executive Director of the Northwest Concrete Masonry Association located in Mill Creek, WA. Young is a Fellow of The Masonry Society and co-chair of the Structural Design Task Group of the Masonry Alliance for Codes and Standards. He may be reached at tcyoung@nwcma.org.

strength of masonry, per the unit strength method, to 1,900 psi. TMS 402-16 further increased this minimum specified compressive strength of masonry walls to 2,000 psi. Since the specified masonry compressive strength is in the denominator of the lap splice length equations of the masonry standard, increasing the specified masonry compressive strength decreases the required lap length.

Section 2107.2 of the 2015 IBC allows an alternative determination of lap splice lengths for ASD for No. 9 Figure 2. A new section of wall is getting Figure 3. Confinement of the started after grouting of the section splice must include transverse bars and smaller. This equabelow. The reinforcement being lapped reinforcement placed within tion was originally printed in extends into the next section of wall.

8 inches of each end of the lap. the Uniform Building Code.

The lap splice lengths calcuoff the centerline of the wall, these equations lated by this equation are dependent on the bar can produce large lap lengths. diameter and the stress in the reinforcement.

For typical ASTM C90 masonry units and The 2015 IBC permits a 72-bar-diameter Type M or S mortar, TMS 402-13 increased cap on SD lap splice lengths. The 2018 IBC the minimum specified compressive includes this same cap for ASD. ADVERTISEMENTâ&#x20AC;&#x201C;For Advertiser Information, visit www.STRUCTUREmag.org

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Lap Splices with Confinement The TMS 402-11 introduced a confinement factor for masonry lap splices calculated by either ASD or SD. When small diameter reinforcement is placed transversely, to cross both the top and bottom ends of a lap splice, the lap lengths calculated by either the ASD or SD sections of the masonry standard may be reduced due to confinement of the splice.

The reduction can be significant but in no case can the reduced lap length be less than 36 bar diameters.

This confinement factor was developed after extensive testing of lap splices with confining reinforcement by the National Concrete Masonry Association. The research found that the transverse, or confinement, reinforcement increases the lap performance significantly.

The transverse bar must be No. 3 or larger placed within the last 8 inches of each end of the lap (Figure 3). Additionally, the clear space between the transverse bars and lapped bars may not exceed 1.5 inches, and the transverse bars must be fully developed in grouted masonry at the point where they cross the lapped reinforcement. Horizontal reinforcement in bond beams can be used to satisfy this requirement.

The authors have participated in masonry industry focus groups to discuss the implementation of this potentially beneficial confinement provision. It requires detailing the masonry lap splices and the location of the transverse confining bar on the design drawings. Even in masonry walls with closely spaced bond beams, most vertical bars only have a crossing horizontal bar at one or the other end of the splice, so an additional horizontal bar may need to be located at the top or bottom of the splice.

The confining reinforcement does not have to consist of continuous horizontal bars; however, the confining reinforcement does have to be developed on each side of the spliced bars and grouted solid.

Some proposed details have suggested short “pigtail” bars in grouted cells. While this would only need attention to placement in fully grouted reinforcement, it is more problematic in partially grouted masonry because it requires additional consideration of blocking off cells to grout occasional adjacent horizontal cells. Details have been produced which have double bond beams at the tops of grout placements. This provides horizontal bars, in adjacent horizontal courses, at the top of one end of a splice and the bottom of the end of the adjacent

Figure 4. Double-height bond beams can be used as one option to properly confine a lap splice and reduce the required lap splice length.

splice (Figure 4). The implication is that all splice lengths need to be the same length and bond beam spacing is set by the splice length or vice versa. Because reinforced masonry walls typically have different sized bars at the ends of shear walls than those that are present in the field of the wall, this approach also requires additional detailing.

If the splice lengths can be standardized and set to a single length, another alternative would be to place intermediate bond beams between typically spaced bond beams to confine the upper end of all the spliced bars (Figure 5). The reduction in lap lengths can be significant. The reduction in the amount of vertical reinforcement required for laps, as well as the ease of construction with shorter laps and the resulting cost savings, can offset the additional horizontal confining steel and grout, especially with the thoughtful use of required bond beams.

Which Approach Should You Use?

Figure 5. The use of intermediate bond beams is another option to confine a lap splice properly. The splice length can be standardized for various bar sizes depending upon the bond beam spacing.

So what approach should be used to determine lap splice lengths? The authors have several observations: • The most economical masonry construction typically uses the shortest laps.

• Keep the lap length shorter than or equal to the grout placement height.

Otherwise, there will be three vertical bars in the lap region in some locations, potentially causing grouting congestion.

• If open-ended units are available, they may improve constructability.

• When solid grouting walls, consider using more frequent, smaller vertical bars with shorter laps.

• If you are using the 2015 IBC and TMS 402-13 for concrete masonry design, standardize on a specified masonry compressive strength, f´m, of 2,000 psi now, rather than increasing to 1,900 psi now and 2,000 psi in the next cycle. That way, in most cases, you will only need to update your structural notes, typical details, and splice length tables once.

• For reinforcing bars centered in 8-inch CMU or thicker walls of typical strengths, with bar sizes up to No. 6, the equations from either the 2013 or 2016 edition of TMS 402 will produce the shortest lap lengths.

• For offset bars up to No. 5 in typical 8-inch CMU walls, try to use a minimum cover of 2.0 inches and the equations from either the 2013 or 2016 edition of TMS 402.

• For No. 6 offset bars in CMU walls, try to use a minimum cover of 2.5 inches, the maximum grout lift height of 5 feet 4 inches, and the equations from either the 2013 or 2016 edition of TMS 402.

• If the minimum cover of 2.0 inches for No. 5 bars and 2.5 inches for No. 6 bars isn’t feasible, or if the bar size is equal to or larger than No. 7, you can either use the lap splice equations from the IBC or use the confinement equations from TMS 402 with special job specific detailing.

• If you are using the confinement equations from TMS 402 and have bond beams, use a bond beam spacing of 48 inches on-center, 32 inches on-center, or 24 inches on-center.

Splicing of reinforcement in masonry walls allows for efficient construction. If low-lift grouting is being used, the use of shorter length vertical reinforcing bars (7 to 10 feet) saves on labor costs. Reinforcing bars may be spliced by lapping, as discussed in this article, by mechanical splices, or by welding. Lapping bars is the most common splicing method and using confinement reinforcement is the latest design option.

Since the use of confinement of lap splices is still a relatively new provision, the authors welcome feedback on specific job details developed and information on how the mason contractor responded to the detail, as well as how the use of confined lap splices impacted the project.▪

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Building Blocks High-Volume SCM Grouts for Masonry

By Jamie Farny

M

asonry has a long performance history as a durable, economical, and attractive building system. It has been used successfully in all climates and can serve as both the structural system and architectural finish. Construction today requires materials that are easy to use and have dependable performance, so manufactured masonry units that have uniform size and properties are much more common than natural (stone) units. Similarly, portland cement-based mortars and grouts are preferred for their consistent setting and strength characteristics.

Portland cement is found in mortar, in grout (when used), and may be an ingredient in units.

With the push toward sustainability, materials such as fly ash are increasingly finding their way into masonry materials, especially by reformulating grout mixtures to include both portland cement and fly ash. Targeted research was undertaken to learn whether mixtures containing high volumes of supplementary cementitious materials (SCMs) could still produce the required strength for grout. This article summarizes the results of many years of research on this topic.

SCMs for Masonry Grout Grout is a fluid mixture of cementitious materials and aggregate for use in fully or partially grouted masonry construction. The cementitious materials typically include portland or blended cement, fly ash, and slag cement.

Conventional grout is made fluid by the addition of water, whereas self-consolidating grout (SCG) relies on chemical admixtures (and sometimes high powder contents) to achieve a highly flowing state. Grout fluidity is important to ensure uniform filling of block cells, which often contain reinforcing bars that may impede the flow of material. There is little distinction between conventional grout and SCG in the hardened state. The standard that guides the production of both conventional grout and SCG is ASTM C476, Standard Specification for Grout for Masonry.

TMS 402/602, Building Code Requirements and Specification for Masonry Structures, requires that grout compressive strength (at 28 days) be a minimum of 2000 psi or equal the compressive strength of masonry, whichever is greater (TMS 402/602 2016).

This article focuses on conventional grouts formulated with portland cement plus high

volumes of fly ash and slag cement, both of which are considered SCMs. Replacing a portion of cement with SCMs helps reduce the environmental impact of the grout. For concrete masonry systems, grout mixtures are the best opportunity to introduce SCMs; the most common SCMs for this purpose are fly ash and slag cement. Prescriptive requirements of ASTM C476 allow for fly ash to be used up to the limit specified for an ASTM C595 portland-pozzolan cement (Type IP), which is 40% by mass of cement. For ASTM C595 portland blast-furnace slag cement (Type IS), the limit for slag is 70% by mass of cement.

Researchers believed they could exceed those limits (which C476 allows by the specified compressive strength method) and still produce an appropriate grout strength.

Impacts on Fresh and Hardened Properties Fly ash and slag cement typically impact both fresh and hardened properties of concrete and grout. The effects of SCMs on hardened properties depend on several factors, including the composition and amount of SCM, the chemistry of the cement, the mixture proportions, and temperature during construction and curing. Each of these considerations should be well understood so that specifiers make informed decisions about SCM usage.

There are two classes of fly ash; Class C has both pozzolanic and cementitious properties, and Class F has only pozzolanic properties.

The research described in the studies noted here all used Class F fly ash. Because Class F and C fly ashes behave differently in certain aspects, it is important to know whether you are using Class F or Class C when formulating grout mixtures.

All fly ashes and slag cements improve the workability of grout. Class F typically delays setting time and results in slower strength gain at early ages. Class C may increase or decrease setting time but does not have much impact on early-age strength gain. Both Class F and C contribute to better long-term strength.

Slag cement also increases setting time. In concrete, Class F is often dosed at 15% to 25% and Class C is used at dosages of 15% to 40% by mass of cementitious material.

The pozzolanic and cementitious properties of SCMs influence the temperature during

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Fly ash is a by-product of the combustion of pulverized coal in electric power generating plants. Fly ash for use in grout must meet requirements of ASTM C618, Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete. Slag cement, previously known as ground, granulated blast-furnace slag (GGBFS), is the glassy material formed from molten slag produced in blast furnaces as a byproduct of the production of iron used in steelmaking. Slag cement must meet requirements of ASTM C989/C989M, Standard Specification for Slag Cement for Use in Concrete and Mortars.

construction and curing. Class F fly ashes are likely to be more affected by cold temperatures, further slowing strength development.

Class C fly ashes and slag cement are less affected by cold temperatures. It is imperative to understand the effects of the fly ash on the curing of the grouted masonry wall, as the potentially slower strength gain needs to be factored into the construction sequencing.

It is also possible that cold weather protection may need to be extended, although there is no code requirement mandating this.

Performance of Grouts with SCMs For grouted masonry, researchers wondered if it would be possible to add much higher dosages of SCMs to grout (known as “high-volume” substitutions of fly ash or slag cement) to reduce the environmental footprint of the wall while maintaining its performance. Researchers looked at varying dosages of SCMs (including by weight and by volume percentages), different combinations of fly ash and slag cement, the influence of dry and wet curing, and age at testing to determine limits at which effective performance could still be maintained. Fonseca and Siggard (2012) found that grouts with up to 40% Class F fly ash, and 80% Class F fly ash plus slag cement, perform as well as conventionally proportioned masonry grouts. The same study also found that 60% fly ash and 85% fly ash-slag mixtures can achieve the minimum required compressive strength of the grout mixture at 56 days, which can be an option for structures that will not be loaded until later ages.

Fonseca and Siggard described five phases of research into SCM replacement grout: • Phases I and II: 0% – 60% fly ash (Figure 1)

Figure 1. Phase I and II grouts that contained up to 60% replacement of portland cement with Type F fly ash. All mixtures that contained up to 50% replacement with Type F fly ash developed a compressive strength of at least 2000 psi at 28 days.

• Phase III: 50% – 80% fly ash plus slag cement (Figure 2) • Phase IV: 45% – 65% fly ash (Figure 3) • Phase V: 65% – 85% fly ash plus slag cement (Figure 4) As part of their research, grout was cured under both wet and dry conditions for the Phase I mixes (CMACN 2009). With little-observed difference between wet- and dry-cured strengths, grout mixtures for Phase II and subsequent Phases were only wet cured. The results show that grout with replacement of 50% (by volume) of the portland cement with a Type F fly ash meets the minimum requirements of the building code at 28 days (2,000 psi). At between 42 and 56 days, all mixture proportions with up to 50% replacement equaled or exceeded the strength of the baseline mixture that contained 100% portland cement. It is interesting to note the significant drop-off in the strength of the

Figure 2. Phase III grouts achieved the required minimum compressive strength of 2000 psi by 28 days. Note: FA = fly ash; GGBFS = ground granulated blast furnace slag.

fly ash mixture that replaced 60% of the portland cement, which indicates the importance of knowing local materials and doing testing so that grout properties are well understood.

Phase III grouts were also wet cured (Figure 2). Here, fly ash was dosed at 25% replacement of cement by weight, with fly ash plus slag at 50%, 60%, 70%, and 80% portland-cement replacement. All of these mixtures were able to achieve the minimum 2000 psi grout compressive strength at 28 days.

that we also protect property in the face of many types of disasters.

High-volume SCM grouts, described in the research discussed here, achieved the required compressive strength within typical construction ages. The key benefit of this approach is to enhance masonry’s environmental footprint by replacing a portion of the portland cement in the grout with SCMs. No matter how masonry is built, it is a cost-effective, safe, and attractive system for a wide range of applications.▪

Summary

The online version of this article contains detailed references. Please visit www.STRUCTUREmag.org.

Masonry construction offers numerous benefits. Properties include long life, durability, and strength. Resilience has been growing in importance as people recognize that the current focus of building codes is life safety and that it is possible to strengthen codes so

Figure 3. Phase IV. High-volume fly ash grouts for masonry, containing up to 65% replacement of portland cement with Type F fly ash, can achieve appropriate grout strength of 2000 psi, but that this may not occur before the age of 28 days.

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Jamie Farny is the Director of Building Marketing with the Portland Cement Association.

He can be reached at jfarny@cement.org.

Figure 4. Phase V. High-volume fly ash plus slag cement grouts for masonry, containing up to 85% replacement of portland cement with Type F fly ash and slag cement, can achieve appropriate grout strength of 2000 psi, but that this may not occur before the age of 28 days.

May 2018

Code Updates TMS 402/602-16 Changes to the Masonry Code

By Richard Bennett, Ph.D., P.E.

A

new edition of Building Code Requirements for Masonry Structures and Specification for Masonry Structures was published in 2016 (Figure 1). In addition to technical updates, there were four nontechnical changes. The first is that the code and specification are now solely sponsored by The Masonry Society (TMS) and are known as TMS 402 (formerly also designated as ACI 530 and ASCE 5) and TMS 602 (formerly also designated as ACI 530.1 and ASCE 6), respectively. ASCE and ACI graciously relinquished their rights to the document in recognition of the maturity of The Masonry Society. The second change is that the code has six fewer pages than the 2013 edition, being one of the few structural codes that have fewer pages than the previous edition (Figure 2). The third change was to incorporate userfriendly tables rather than text throughout the document. The fourth change is not a direct revision to the 2016 edition; TMS has approved a six-year code cycle, so the next TMS 402 code will be the 2022 edition.

Shear Friction Provisions A significant technical change was the addition of shear friction provisions. Masonry shear walls that have a low axial compressive load and a low height-to-length ratio are

Figure 1. The 2016 TMS 402/602.

vulnerable to shear sliding, which normally occurs at the base. Shear sliding can cause damage to the masonry due to the simultaneous actions of the shear stress, compressive stress, and dowel action. There are similar shear friction provisions for Figure 2. Code facts – historical page counts.

Allowable Stress Design (ASD) and Strength Design (SD). One ASCE 7-16 that reduces the minimum design set of equations is for low height-to-length strength of anchors not governed by tensile shear walls, while the provisions for flexurally- yielding or shear yielding from 2.5 times the dominated walls account for the fact that not factored force to 2.0 times the factored force all the reinforcement crossing the horizontal for seismic applications, will result in more shear plane will contribute to the clamping efficient use of anchor bolts in masonry. force and provides a reduced coefficient of friction. Although shear friction will govern Veneer Cavity Width in a few cases, the reduction in the capacity of the wall is small, in general. Shear friction can Increased energy requirements for building govern with shear-dominated walls. However, envelopes has resulted in wider cavities in these long walls (big box structures) are gener- brick veneer walls to accommodate increased ally governed by architectural requirements and insulation thicknesses. The code was changed not structural requirements; there is usually to allow an increased cavity width from more than sufficient structural strength. Figure 4½ inches to 65⁄8 inches for the prescrip3 provides Shear Friction Design equations. tive design of veneer anchors under certain conditions. The increase was primarily to allow for increased thicknesses of insulation Anchor Bolt Provisions and secondarily to recognize that ⅝-inch There were two major changes to the anchor sheathing is typically used instead of ½-inch bolt provisions. One was to increase the nomi- sheathing. The requirements for anchors nal shear masonry crushing strength from Bvnc are adjustable anchors with two pintles, a = 1050 4√f´mAb to Bvnc = 1750 4√f´mAb. This maximum span of the adjustable portion of increase was based on examining 345 anchor 2 inches, and either ¼-inch barrel anchor, a bolt tests. The average ratio of experimen- plate or prong anchor at least 0.074-inchtal strength to nominal strength was 2.33 thick and 1¼ inches wide, or a tab or two with the previous equation. The change still eyes formed of minimum size W2.8 wire results in a conservative prediction of nominal welded to joint reinforcement. Joint reinstrength, with the average ratio of experi- forcement with cross and longitudinal wires mental strength to nominal strength being of size W2.8 are also permitted. Anchor 1.49. A similar change was made to Allowable capacities of adjustable anchors are primarStress Design. The second change was to the ily controlled by bending of the pintles at interaction between the tensile and shear a maximum allowed offset of 1.25 inches. strength of anchor bolts. Previously, there This capacity is independent of cavity width was a linear interaction diagram. This was and is not affected by the code change. The changed to an elliptical interaction equation requirements for anchors for increased cavity with an exponent of 5/3, based on testing. widths have compression capacity that equals These two changes, coupled with a change in or exceeds current requirements.

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Concentrated Loads TMS 402 has provisions for distributing concentrated loads in walls based on a 2 vertical to 1 horizontal dispersion terminating at half the wall height, or the edge or opening of a wall. This resulted in very small distribution lengths for concentrated loads near the edge of a wall and no dispersion for loads at the edge of a wall or an opening. This could result in unconservative designs as the axial load generally increases the moment capacity.

A provision was added that a concentrated load could be distributed at 3 vertical to 1 horizontal on one side of an opening. This steeper dispersion will continue away from the opening up to one-half the height of the masonry below the load so that the dispersions can be truncated independently on each side of the bearing (Figure 4).

Additional Changes Other technical changes include deleting the prescriptive requirements for masonry piers in strength design, as most of the requirements were redundant with the current prescriptive seismic design. The requirement that the nominal bar diameter does not exceed one-eighth of the least nominal member dimension that

Figure 3. Shear friction design equations.

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Figure 4. Load distribution at openings.

was in strength design was also added to allowable stress design. This provision minimizes the chances of splitting of the masonry. The tables for the prescriptive design of partitions in Chapter 14 were expanded to include out-ofplane loadings from 5 psf to 50 psf. Cast stone (ASTM C1364-16 Standard Specification for Architectural Cast Stone) and manufactured stone (ASTM C1670-15 Standard Specification for Adhered Manufactured Stone Masonry Veneer Units) were added as approved materials in TMS 602.

There were several organizational, format, and editorial changes. Reinforcement requirements, particularly development and splice length requirements, had been scattered across three chapters: Chapter 8 – Allowable Stress Design, Chapter 9 – Strength Design, and Chapter 11 – AAC Masonry.

These requirements were consolidated and moved to Chapter 6 – Reinforcement, Metal Accessories, and Anchor Bolts.

The 2013 TMS 402/602 had three quality assurance tables (Quality Assurance Level A,

B, and C) and the tables were repeated in both the code (TMS 402) and the specification (TMS 602). The tables were removed from TMS 402; TMS 402 now references TMS 602. The tables were also modified so that there are now two tables, one table for Minimum Verification Requirements and one table for Minimum Special Inspection Requirements.

This approach segregates minimum test requirements from the inspection tables.

Some formatting changes include combining requirements that were in multiple sections, and challenging to follow, into tables. This is for the ease of users (see the sidebar for further information). Definitions were added for beams and pilasters, and other definitions were modified and clarified. In particular, there were inconsistencies in definitions of loads. TMS 402 now just refers to either allowable stress design level loads or strength level loads.▪ Richard Bennett is a Professor of Civil and Environmental Engineering at the University of Tennessee, Knoxville. He was chair of the 2016 TMS 402/602 Committee and is currently 2nd Vice-Chair of the 2022 TMS 402/602 Committee.

User-Friendly Tables

By Charles Haynes, P.E., LEED AP The author is a principal at one of the Southeast’s largest structural engineering firms and has participated in the TMS 402/602 code development for over 10 years. During the 2013 TMS 402/602 code cycle, Charles was actively involved in efforts to simplify the organization and layout of the code to make it more designer-friendly – provisions that would be easier for the user to locate and reduce flipping back and forth between chapters during design. The result was an entirely new layout to the code based on the way a project is engineered.

Bolstered by the positive response to the designer focused efforts in the 2016 TMS402/602 code cycle, further efforts were launched to help the user by unpacking some specific sections into user-friendly tables to quickly identify needed information.

As the saying goes, a picture is worth a thousand words. That may be a stretch in this case, but a table is worth several words and, more importantly, your time and sanity. Time demands on everyone in this industry have seemed to skyrocket, and codes have become much more complex and harder to follow.

Consider the example herein from a provision in the 2013 TMS 402 for the Effective Flange Width when designing the intersection of a wall. You might read the 2013 code language several times and then your phone rings, and you think, “What did I just read?” Now consider the same provision shown as it is presented in the 2016 TMS 402. The implementation of a table format allows users to identify necessary information quickly.

As a user, the author applauds the efforts of the committee to simplify the TMS 402/602. The new, user-friendly tables are one example of this. As the committee has now moved to a 6-year code cycle, the next release will be the 2022 TMS 402, and we can look forward to more user-friendly updates.

Charles Haynes is a Principal with Structural Design Group (SDG) in Nashville, TN. Charles is a member of the Board of Directors for The Masonry Society (TMS) and on several TMS 402 committees, including TMS 402 Main Committee, and is actively involved in developing and maintaining masonry building codes (TMS 402/602) adopted by the International Building Code.

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Excerpt – 2013 TMS 402

Excerpt – 2016 TMS 402

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T

he deterioration of the masonry façade at St. Francis of Assisi Catholic Church, an English Gothic-style structure originally constructed in 1895 and located in Staunton, Virginia, presented a life-safety issue for parishioners and necessitated the evaluation of the historic structure. Significant water infiltration, cracking, and spalling of the original greenstone façade had progressed to the point that overhead protection was installed to serve as a shield against falling debris. Cracking and staining of the limestone elements and missing copper elements also contributed to the life-safety concerns, as well as diminished the aesthetic appearance of the church. While previous restoration efforts to address ongoing issues had been conducted, such as repointing and replacement of the stone in the bell tower with bluestone, the problems persisted. In 2012, WDP & Associates (WDP) was retained to provide an evaluation of the façade and to develop a comprehensive repair and restoration program.

The field investigation revealed that the original construction of the walls, from exterior to interior, consisted of six- to eight-inch thick blocks of Pennsylvania ashlar greenstone, or serpentine stone, followed by a rubble masonry infill and two full wythes of brick masonry. The window surrounds were comprised of limestone, which was also employed at capstones and other decorative pieces.

Copper elements appear on the church structure as well, most noticeably on the bell tower. Generally, the limestone was in good condition, but the serpentine stone had experienced significant distress.

Restoring History

19th Century Stone Church Receives New Façade Balancing Safety with Historic Integrity From the beginning, the parish’s primary objective was to ensure that the design would fully resolve the problems while remaining true to the historic integrity of the building. Additionally, the execution of the work could not interfere with the daily parish activities or impact the nave’s interior finishes. A successful restoration would provide a safe, reliable structure which would serve the parish for another 100 years.

Several restoration methods were evaluated, including consolidation treatments or using cast concrete to match the existing greenstone as outlined in historic preservation briefs. However, neither of these methods met the parish’s long-term criteria, as the serpentine stone is typically not a good candidate for consolidation treatments and the stone deterioration was far too extensive and widespread.

Replicating the Façade with Granite

Deterioration of serpentine stone.

Ultimately, the parish decided on a comprehensive overhaul of the entire exterior wall system. The existing greenstone and rubble masonry would be removed, the remaining brick would be repointed, and a new brick wythe and grouted collar joint would be installed behind new four-inch-thick granite stone. To ensure full integration of the new components with the existing limestone to remain, the pointing of the new granite coincided with repointing of the limestone.

The design accounted for the original look of the building, a concern of the local historic preservation council as well as the parish, by utilizing light imaging, detection, and ranging, or LiDAR. Scans of the existing church elevation were collected to ascertain the exact dimensions of every existing green serpentine stone and replicate them with mountain green granite stone. Extensive shop drawings assigned a unique number to every stone used in the wall. Each new granite stone matched the dimensions of the original serpentine with the exception of thickness to avoid additional loading on the foundation walls. The new stone was palletized and

External strengthening buttress.

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By John Grill, P.E., and Rex Cyphers, P.E.

Granite shop drawing and field layup – each granite element is assigned a unique identification number.

shipped to the site by section number, and each section was laid out to check carefully for fit and dimension. Using granite stone rather than cast concrete provided a more durable façade while staying true to the traditional masonry construction methods. The laser scans ensured that the overall look of the church would not be changed, as the same stone pattern was precisely replicated.

Installation Challenges Removal of over half of the original wall thickness for the performance of the extensive repairs, without disruption of services, posed an installation challenge. A unique phasing plan and temporary external strengthening measures were developed to circumvent these challenges.

External supports, consisting of steel columns anchored through the exterior stone masonry, were installed at the buttress locations. WDP performed a structural analysis to determine the maximum area of the wall that could be removed without compromising the overall stability of the structure. The results of the analysis dictated the phasing plan; small sections of stone and inner brick wythe were removed at a time, followed by repointing and installation of materials, including glass fiber reinforced polymer (GFRP) bars at areas of high tensile stresses, before proceeding to the next section. GFRP bars were selected for their high tensile capacity, small diameter, and the longevity provided by not being susceptible to corrosion. The external strengthening was removed at the completion of infill walls, and a similar sequence then occurred at alternating buttress locations. In using these methods, the exterior walls retained enough stability to resist out of plane loads and support the roof structure, even while over half of the overall wall thickness was removed.

The restoration plan also called for close replications of the mortar and the brick replacement. Through testing at the investigative phase and several rounds of submittals and mockups, a replacement mortar was designed to replicate the original mortar properties, aggregate color, and gradation. Additionally, the new brick wythe consisted of hand-molded brick carefully selected to match the properties of the original brick and was joined with existing wythes using traditional header courses.

Due to the reduction of stone thickness between the original serpentine and the replacement granite, GFRP bars were incorporated into the walls at locations of high tensile stress. The GFRP was chosen over conventional reinforcing steel due to its high tensile capacity, better strain compatibility, small diameter, and longevity due to its insusceptibility to corrosion.

Various copper elements of the original structure had either deteriorated or fallen off the church entirely, including the copper spires of the bell tower which had been replaced with cast stone.

As part of the restoration project, the original architectural details and the removed samples of intricate copper pieces were used to reconstruct replica copper details. Some of the more intricate pieces STRUCTURE magazine

Replacement of copper narthex spire.

were handmade in Germany. Dentil courses, spires, and decorative elements were replicated to match the original church construction.

Accessing the structure presented its own challenges, as no construction loads could be placed on the roof. Extensive scaffolding was designed and installed to be cantilevered around the bell tower.

Fencing and overhead protection safeguarded parishioners as the church continued its services.

Over its 100-plus years of service, the limestone had incurred staining from various elements. Cleaning and restoration of these elements provided a fresh look to match the other façade renewal. Other restoration activities performed included: re-anchorage of coping stones using stainless steel anchors; installation of new copper flashings; replacement of the cedar ceiling at the bell tower; waterproofing of the bell tower; restoration of the wooden window trim and louvers; restoration of the decorative metal railings; and the replacement of damaged slate shingles.

Rededication After fourteen months of restoration with no disruption of services, the entire construction program was completed and the church celebrated with a rededication of the building on May 8, 2016. The façade reconstruction of St. Francis of Assisi Catholic Church provides an example of how to blend traditional restoration methods, such as matching traditional mortars and brick and the use of handmade replicas of the decorative copper elements, with new technology in the form of laser scanning, temporary strengthening, GFRP reinforcing, and complex access scaffolding. Using the best of old and new methods allowed the team to improve and restore this 100-plus-yearold façade, helping to ensure that it will remain an important gathering place for another century to come.▪

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John Grill is an Associate with WDP & Associates Consulting Engineers, Inc. in Manassas, Virginia. He can be reached at jgrill@wdpa.com.

Rex Cyphers is a Principal at WDP & Associates Consulting Engineers, Inc., in Manassas, Virginia. He can be reached at rcyphers@wdpa.com.

Project Team Owner: Catholic Diocese of Richmond, VA Engineer: WDP & Associates, Consulting Engineers, Manassas, VA General Contractor: Lantz Construction Company, Broadway, VA Stone Mason: Rugo Stone, Lorton, VA Granite Supplier: ColdSpring, Cold Spring, MN Copper: The Durable Restoration Company, Columbus, OH May 2018

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PT R O F I L E

he National Council of Examiners for Engineering and Surveying (NCEES) is a nonprofit organization made up of engineering and surveying licensing boards from all U.S. states and territories and the District of Columbia. Since its founding in 1920, NCEES has been committed to advancing licensure for engineers and surveyors in order to safeguard the health, safety, and welfare of the U.S. public.

NCEES develops, administers, and scores the exams used for engineering and surveying licensure in the United States. It also facilitates professional mobility and promotes uniformity of the U.S. licensure processes through services for its member licensing boards and licensees. These services include: Engineering Exams: The FE exam is generally the first step to becoming a professional licensed engineer. The PE exam is designed to test for a minimum level of competency in a particular engineering discipline. It is intended for engineers who have gained a minimum of four years of work experience in a discipline. The SE exam is designed for engineers who practice in jurisdictions that license structural engineers separately from other professional engineers.

Surveying Exams: The FS exam is generally the first step to becoming a professional licensed surveyor. The PS exam tests the ability to practice the surveying profession competently.

Exam Prep Materials: NCEES exam preparation materials are developed by the same people who create the licensing exam.

NCEES Records Program: The program is designed for currently licensed engineers and surveyors who are looking for an easier and faster way to complete the licensure process. An established NCEES Record will include most – if not all – of the materials you need to apply for comity licensure in additional states and territories.

Credentials Evaluations: The service is intended primarily for candidates who have earned degrees outside the United States and are pursuing licensure.

CPC Tracking: Most state licensing boards require licensed engineers and surveyors to meet a continuing professional competency (CPC) requirement to renew a license. You can track and report your CPC requirements for free through your MyNCEES account.

Engineering Education Award: The annual award has a $25,000 grand prize and recognizes college engineering programs for engaging their students in collaborative projects with licensed professional engineers.

Surveying Education Award: The annual award has a $25,000 grand prize and recognizes surveying/geomatics pro1-864-654-6824 grams that best reflect NCEES’ mission to outreach@ncees.org advance licensure in order to safeguard the www.ncees.org health, safety, and welfare of the public.

RECORDS “An NCEES Record makes it fast, easy, and convenient to apply for additional P.E. licenses in other states.”

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Build your NCEES Record today. ncees.org/records

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SIMPSON STRONG-TIE

Commercial Infrastructure Solutions

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rom adhesive and mechanical anchors to curtain-wall connectors, we are committed to developing new technology that advances the commercial construction industry. Here are some of the latest product solutions that we have engineered and tested to address your specification needs.

Structural Connectors for Cold-Formed Steel The new SHH steel header hanger box header is used to support traditional CFS box headers that are fabricated with top and bottom tracks, as well as large-flange lay-in headers common in curtain-wall construction. The SHH is engineered to install with fewer screws and finishes flush to reduce drywall buildup, saving installation time and cost.

Composite Strengthening Systems™ (CSS)

We offer adhesive anchors and mechanical anchors for infrastructure, commercial and industrial construction.

• SET-3G™ is our latest innovation in epoxy adhesives and is now code listed in ICC-ES ESR-4057. The high-strength anchoring adhesive can be installed in extreme concrete temperatures from 40°F to 100°F, as well as in dry or water-filled holes. SET-3G provides the high bond strength values needed for a variety of adhesive anchoring applications.

• The THDSS Titen HD® screw anchor is the first stainless-steel screw anchor that is available in ⅝-inch and ¾-inch diameters.

The added diameters give engineers access to higher-load-capacity screw anchors for use in severely corrosive environments.

Until the release of the new diameters, engineers designing for corrosive conditions were forced to use stainless-steel expansion anchors, which require much greater spacing from edges and between anchors. The stainless-steel Titen HD screw anchor is now available in diameters of ⅜-, ½-, ⅝-, or ¾-inch and is code listed in IAPMO UES ER-493 (concrete) and ICC-ES ESR-1056 (masonry).

1-800-999-5099 www.strongtie.com/css

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Anchor Solutions

We offer two solutions for your concrete repair and strengthening projects: fiber-reinforced polymer (FRP) and fabric-reinforced cementitious matrix (FRCM).

• FRP – for the structural reinforcement of concrete, masonry, steel and timber elements, we provide corrosion-resistant and highperformance FRP products including carbon-fiber and E-glass fabrics, North America’s first code-listed pre-cured laminates, and FRP anchors.

• FRCM – combines a high-performance sprayable mortar with a carbon-fiber grid to create a thin structural layer that will not add significant weight or volume to the existing structure. FRCM can be used to repair and strengthen concrete and masonry structures for seismic retrofit or load rating upgrades.

In addition, we offer complimentary CSS design services for engineers and other Designers. Our experienced technical representatives and licensed professional engineers provide design services, field support and training free of charge – serving as your partner throughout the entire project cycle.

To learn more about our CSS products, or to speak with an engineer or local specialist who can help you determine the best solution for your concrete repair or strengthening application, visit our website or call and speak to a representative.

Designed for a flush finish.

Cover

Connectors

for Cold-Formed Steel Construction

C-CF-2017 | (800) 999-5099 | strongtie.com

Fewer screws. Less buildup. With its flush profile, the new SHH steel header hanger minimizes drywall buildup. Fully tested, the SHH also requires fewer screws to speed up installation and has value-engineered hole patterns to accommodate different load levels.

To learn more about the easy-to-install SHH, visit go.strongtie.com/shh or call (800) 999-5099.

Download our latest CFS Catalog Š 2018

Simpson Strong-Tie Company Inc. CFSSHH18

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CLARKDIETRICH BUILDING SYSTEMS

Delivering the solutions that stop your Hassles.

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etbacks, delays and hurdles. Small obstacles, little screwups, and minor annoyances. Every project has them, right? No big deal. You just roll with it and move on.

But at ClarkDietrich, we look at the meddlesome problems you encounter every day from a different perspective.

We have labeled the challenges that plague you collectively as the Hassles. From tackling tedious searches for product details, to playing catchup with codes and trends, to getting bogged down by the complexities of BIM, these hidden dangers come at a cost to your productivity, profitability, and peace of mind.

Because the Hassles can rear their ugly heads at every stage in the building process – from design, to delivery, to construction – it takes a full, systemic approach to dial them out of the picture. In the world of cold-formed steel framing, no manufacturer is more prepared to do that than ClarkDietrich.

Little Hassles can add up to big trouble.

A Full Arsenal for Eliminating Challenges We have made it our mission to identify and eliminate little Hassles, so they do not work themselves up into bigger troubles. Our comprehensive array of resources is totally dedicated to preventing problems and promoting progress.

Engineering Support One of the chief ways to avoid Hassles is to enlist experienced allies. With four offices, over 50 engineers and technicians on staff, and nationwide reach, ClarkDietrich Engineering Services can take calculations, shop drawings, LEED® compliance, and more off of your hands.

You can also turn to our technical service experts for immediate responses to general questions, help with more detailed specification

Product Solutions Leading our lineup of product solutions is ProSTUD® Drywall Steel Framing. It is a complete system in and of itself. ProSTUD, along with a number of other products, is backed by iTools for fast mobile lookup of selection and specification data We can also cite solutions developed to take aim at specific issues of growing industry concern. If your next project calls for a better way to combat noise, check out RC Deluxe® Resilient Channel. It increases the acoustical performance of walls, reduces installation errors, and is backed by extensive testing data to bolster your specs.

We are also leading the charge on small components that have big advantages. For example, our new Drift FastClip™ Slide Clip is a deflection solution that allows 2-inch vertical – and lateral – deflection. It’s part of our comprehensive ClipExpressSM service, which can deliver a vast array of clips, connectors, and accessories overnight.

Championing a Greater Cause Innovation. It is not just something we talk about. It is what we do. ClarkDietrich is known for gaining greater insight into the obstacles and inefficiencies that affect you. Better still, we have a proven track record of providing practical solutions that achieve demonstrated results in eliminating your challenges. Learn more about our ongoing mission at stopthehassles.com.

And, as always, our full 1-800-543-7140 portfolio of products, digital info@clarkdietrich.com tools, and support services can clarkdietrich.com Our products, digital tools, and services create a full system. be found on our website.

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issues, as well as support for SubmittalPro®, our online product submittal system.

Š 2018 ClarkDietrich Building Systems

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Meeting More Construction Needs

M

APEI has long been known in the Americas as a supplier of quality systems for the installation of all types of flooring – carpet, vinyl, wood, tile, and stone. Then, products for the repair and renovation of concrete used in buildings and infrastructure were added to our portfolio. Now, MAPEI is introducing more new categories of construction products to the Americas – products that have been developed and proven in other MAPEI markets, as well as brand new products.

Cement Additives Optimize Manufacturers’ Processes

Concrete Admixtures Add Strength and Flexibility MAPEI Americas moved into the concrete admixture market in the United States through the acquisition of General Resource Technology, Inc. (GRT) in 2014. A regional admixtures manufacturer founded in 1993, GRT marketed concrete admixtures and auxiliary products for the concrete industry in the central United States. The company’s products have been routinely used to produce high-performance concrete mixes that are called upon to perform in all weather conditions. With MAPEI’s resources and innovation, this new North American subsidiary will continue to incorporate the latest product technology available to meet customer needs and focus on continuing the development of next-generation concrete admixture products.

MAPEI’s Research and Development teams in Europe have been working to supply concrete mixing plants, the precast concrete sector, and large construction companies with concrete admixtures since 1992. These admixtures, developed in Europe and now introduced to North America through GRT, have helped build some of the largest edifices and major infrastructure projects around the world, and now they are becoming available in the Americas.

Underground Construction Team Offers Technology and Products MAPEI has entered the underground technology arena in North America with a team of specialists who are working with contractors, engineers, and owners’ representatives for tunneling, hard-rock mining, and other large underground projects. MAPEI has a solid core group of products to meet the needs of this market segment, and the depth and breadth of knowledge of the MAPEI R&D people helps find solutions for the challenges that engineers encounter in this field.

MAPEI’s product solutions for underground construction encompass:

• Admixtures, alkalifree accelerators, and hydration control for the improvement of sprayed concrete.

• Soil-conditioning systems, sealants, abrasion control, and annulus grouting systems for mechanized tunneling.

• Injection products that include micro-cements, polyurethane (PU) technology, acrylic resins, mineral grouts, and anchors.

• Sprayable membranes, PVC sheet membranes and ancillary products for waterproofing.

• A sprayable mortar-based system for fire protection plus epoxy final coatings.

• Gunite and repair mortars for rehabilitation.

Below-grade Waterproofing Excels at Keeping Projects Dry MAPEI has been heavily engaged and very successful in below-grade waterproofing markets around the world for some time and is now introducing two below-grade waterproofing systems to the Americas – the Mapeproof ™ sodium bentonite geotextile waterproofing membranes for blindside waterproofing and the Mapethene™ self-adhering, rubberized-asphalt sheet waterproofing membranes for positive-sized waterproofing. Supporting these waterproofing products is a complete line of detailing products and accessories.

Mapeproof membranes are offered in a standard-grade version (Mapeproof HW) and an alternate grade designed specifically for sites where contaminated or salt groundwater is present (Mapeproof SW). Mapethene membranes are offered in both high-temperature (Mapethene HT ) and low-temperature (Mapethene LT) versions.

Supporting these waterproofing products is a complete line of detailing and accessories.

Elastomeric Coatings Provide the Perfect Finish The Elastocolor® product line of wall coatings is the latest extension to MAPEI’s Concrete Restoration Systems (CRS) category and also showcases MAPEI’s creativity and innovation. Ideally suited for the concrete restoration and waterproofing market, Elastocolor Flex, Elastocolor Coat, and Elastocolor Paint provide decorative and protective finishes for vertical, above-grade building facades and structures. These products enable building owners to make the right performance decisions, based on specific conditions that they encounter on their projects.

“These coatings are engineered to meet high-performance standards and protect against the deleterious effects of harsh environmental conditions,” said Kevin Smith, National Sales Director for CRS. “The Elastocolor range provides yet another reason to choose MAPEI for single-source repair and protection solutions.”

MAPEI is growing. Wherever construction 1-954-246-8888 is underway, MAPEI has products and www.mapei.com systems for builders.

S T R U C T U R E solutions 34-SS May 2018

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Starting at the beginning of the concrete cycle, MAPEI’s cement additives provide innovative solutions for cement producers. For example, cement additives allow a reduction of clinker content while offering the same mechanical performance of the cement, guaranteeing a 5% to 10% reduction in carbon dioxide emissions plus a savings in non-renewable raw materials. The cement additives being introduced in the Americas include grinding aids, strength enhancers, pack-set reducers and CR(VI)-reducing additives for all types of cement, as well as air-entraining agents for masonry cement.

MAPEI

MAPEI provides a world of Concrete Restoration Systems • Concrete Repair Mortars • Corrosion Protection • Construction Grouts • Waterproofing

• Sealants and Joint Fillers • Coatings and Sealers • Epoxy Adhesives • Decorative Toppings

• Cure and Seals • Densifiers • Structural Strengthening Products

MAPEI offers a full spectrum of products for concrete restoration, waterproofing and structural strengthening. Globally, MAPEI’s system solutions have been utilized for bridges, highways, parking garages, stadiums, building and other structures.

Visit www.mapei.com for details on all MAPEI products.

MAPEI Americas

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PROFILE

Ground Improvement Solutions

S

FOUNDATION COMPANY Aggregate Pier® systems have also been successful at mitigating total and differential liquefaction settlements beneath structures in highly seismic areas, as measurably demonstrated during large earthquakes in New Zealand and Ecuador.

Worldwide Partner Geopier has licensed installers in all of North America, as well as in Central and South America, Europe, New Zealand, Australia, the Philippines, South Korea, and the Middle East. The designbuild model allows local Geopier engineers to work directly with structural engineers to develop a ground improvement solution for projectspecific soil conditions and building loads.

The 30-year old company has provided ground improvement for over 8,000 projects worldwide, including high-profile projects such as NASA’s Stennis Space Center in Mississippi and the Assembly Row 5-block mixed-use development in Massachusetts.

Through dedicated research and develop1-800-371-7470 ment, Geopier continues to expand system info@geopier.com capabilities to meet virtually all foundawww.geopier.com tion design challenges.

GEOPIER GROUND IMPROVEMENT CONTROLS STRUCTURE SETTLEMENT GIVE YOUR STRUCTURE STABILITY Work with Geopier’s geotechnical engineers to solve your ground improvement challenges. Submit your project specifications to receive a customized feasibility assessment and preliminary cost estimate at geopier.com/feasibilityrequest.

GEOPIER IS GROUND IMPROVEMENT® S T R U C T U R E solutions 36-SS May 2018

800-371-7470 • geopier.com info@geopier.com

ADVERTORIAL

tructural engineers choose Geopier ground improvement systems for a variety of good reasons. Geopier GP3®, Impact®, Rampact®, X1®, Armorpact®, GeoConcrete®, and Densipact® systems have supported thousands of structures around the world.

These ground improvement systems can often replace the need for deep foundations, such as driven piles, drilled shafts or augered cast-in- place piles, effectively allowing structural engineers to convert to less expensive shallow foundation systems. Geopier ground improvement allows shallow foundations to be designed for high soil bearing pressures, sometimes up to 10 ksf, while controlling settlements.

Geopier’s rigid inclusion systems are used in very poor soils (e.g. variable fill or soft, organic soil) to support heavy building loads and provide an advantage over pile foundations because no structural pile caps are required. Geopier’s Rammed

GEOPIER

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PROFILE

ANTHONY FOREST

nthony Forest Products Company, LLC, is now part of the Canfor Group of Companies.

Anthony/Canfor owns and operates two glulam manufacturing plants in El Dorado, Arkansas, and Washington, Georgia.

Anthony/Canfor manufactures and markets engineered wood product under the Power Products® brand. Our Power Products are manufactured with superior strength southern yellow pine machine stress rated lumber. All lumber is sourced internally from Canfor’s southern pine mills located throughout the Southeast United States. This vertical integration provides our glulam plants consistent supply of high-grade material, allowing them to produce quality products in an efficient, cost-effective manner, delivered on time to our stocking distribution network throughout the U.S. Power Products are manufactured with exterior grade (wet use) adhesives that comply with all recognized standards. Anthony/ Canfor offers a wide range of sizes and lengths (up to 60 feet) with or without camber.

Anthony/Canfor is an active member of the APA EWS. Our Power Products are manufactured in accordance with ANSI A190.1 and APA standards, including all required quality control inspections,

tests, and record keeping. In addition, our glulams are recognized under the ICC ESR 1940 code report.

For years, design professionals have specified glulams for their aesthetic appeal. In today’s changing building environment with wood being used in tall buildings, glulams often are the best choice for a wide variety of applications. Glulams are easily installed using conventional equipment and tools. Our Power Products brands provided designers cost-efficient, high-strength solutions to load-bearing structural applications.

As an added resource, all Power Product® literature is found on our website. Also, single-member sizing software, Power Sizer® powered by iStruct™ is available as a free download at the website.

ADVERTORIAL

A

CREATE STRONGER, LONGER LASTING STRUCTURES PO WER PRESERVED GLUL AM ® (PPG) BEAMS AND C OLUMNS fEAtURES

• PPG beams and columns comply with AWPA U1-16 Standard • Oil based wood preservatives dissolved in low odor mineral spirits • Exterior use, above ground and ground contact retentions • 2400Fb-1.8E Southern Yellow Pine Glulam • Available in 2 7/16“, 3 1/2“ , 5 1/4“ widths, I-joist compatible and framing lumber depths • One piece installation. No nailing or bolting like multi-ply lumber • 25 year warranty from treater • Large stocking distribution network throughout U.S. • Ideal for simple, multi and cantilever span applications including deck beams, raised floor construction, coastal boardwalks and pier and beam applications

Anthony Forest Products is part of the Canfor Group of Companies w w w. c a n fo r . c o m

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Anthony Forest Products Company, LLC

©

12/8/17 10:10 AM

LEARN analysis and design of concrete floor systems Visit: www.StructurePoint.org > Resources > Design Examples

Two-Way Flat Plate Concrete Floor System Analysis and Design The two design procedures shown in ACI 318-14: Direct Design Method (DDM) and the Equivalent Frame Method (EFM) are illustrated in detail to analyze and design two-way flat plate system. The hand solution from EFM is also used for a detailed comparison with the analysis and design results of the engineering software program spSlab including detailed deflection calculations.

Two-Way Concrete Floor Slab with Beams Design and Detailing The Equivalent Frame Method (EFM) presented in ACI 318-14 is illustrated in detail in this example to analyze and design two-way floor slab with beams.

The EFM solution is also used for a detailed comparison with the analysis and design results of the engineering software program spSlab. This example highlights the slab interaction with the longitudinal and transverse beams and their effect on the system flexural and torsional stiffness including detailed deflection calculations.

Two-Way Flat Slab (Drop Panels) System Analysis and Design The Equivalent Frame Method (EFM) presented in ACI 318-14 is illustrated in detail in this example to analyze and design two-way flat slab with drop panels system. The EFM solution is also used for a detailed comparison with the analysis and design results of the engineering software program spSlab. This example highlights code based selection of drop panel dimensions, analysis process of non-prismatic slab with drop panels, the crucial role of drop panels in resisting two-way shear at columns, and detailed deflection calculations.

Two-Way Joist Floor (Waffle Slab) System Analysis and Design The Equivalent Frame Method (EFM) presented in ACI 318-14 is illustrated to analyze and design two-way waffle slab system. The EFM solution is also used for a detailed comparison with the analysis and design results of the engineering software program spSlab. This example highlights code based selection of rib and drop head dimensions, analysis process of non-prismatic slab due to the presence of longitudinal and transverse ribs and drop heads, two-way shear check for waffle slabs, and detailed deflection calculations.

A complete concrete design resource

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USG CORPORATION

Concrete Structural Panels Are Taking Modular Construction to the Next Level

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The UL H501TM Fire Design Perhaps most critically, USG Structural Panels do not compromise on fire resistance or life safety. In fact, USG has developed the only 2-hour UL-certified fire design for use in permanent modular construction. The design, UL H501, enables modular builders to achieve a 2-hour fire rating in significantly less time, and with reduced space, resources and money.

The UL H501 design is both innovative and simple. Where traditional assemblies require two to three layers of drywall as the ceiling, this new design incorporates a ¾-inch-thick USG Structural Panel on top as the subfloor and only a single layer of USG Sheetrock® Brand Firecode® C Gypsum Panel on the bottom of the ceiling joists.

This reduces labor and material costs while speeding up production.

Greater Design Flexibility The H501 design also affords engineers greater design flexibility when it comes to building height, floor plans, and floor-covering selection.

Requiring only 12⅝ inches in height, the UL H501 design is thinner than typical existing modular fire-resistant assemblies by

at least 12 inches per floor. This allows for either additional floors within the same building height or more headroom per floor, which enhances design flexibility and makes modular construction more competitive with on-site, conventional construction.

Since beams are part of the H501 assembly, the design also affords modular professionals the flexibility to create open floor areas with multiple, adjacent modules without walls for open dining rooms, lobbies or common areas, while still maintaining the 2-hour floor/ceiling rating.

There are also three different means of holding fire and sound insulation under the subfloor, allowing greater flexibility when adding plumbing services and electrical wiring.

The H501 design also passed the 2-hour fire test without an insulated floor covering, meaning that there’s no mandatory underlayment; designers now have full flexibility in the selection of floor coverings without affecting the floor/ceiling rating in any way.

ADVERTORIAL

ermanent modular construction is revolutionizing the way we think about building by enhancing efficiency, increasing quality and reducing construction delays. The demand for modular construction has grown significantly in recent years, and as a result, modular builders have begun searching for ways to streamline and improve their manufacturing processes.

An effective way in which modular builders and engineers can reduce their material costs while boosting productivity is by switching from the use of traditional poured concrete to concrete structural panels.

Lighter than poured concrete, they install like wood sheathing and are mold-, moisture-, and termite-resistant, providing a faster, easier and more efficient way to build floors and roofs.

USG Structural Solutions offers a portfolio of high-strength, dimensionally stable, reinforced concrete panels that are specifically designed for use in noncombustible construction, including modular applications. The use of USG Structural Panels eliminates the need for on-site concrete mixing; the panels are factory cured – subject to rigorous quality-control standards – and are shipped ready for installation. Since there’s no time spent waiting for the panels to cure, crews can install electrical and mechanical services immediately after fastening the panels.

Lighter Materials Equal Lower Costs Poured concrete is often one of the biggest detriments to a modular builder’s schedule and budget due to the time it takes to set and cure, as well as the additional transportation costs its weight incurs. Swapping in a fully noncombustible, pre-cured, lighter-weight concrete product such as USG Structural Panels eliminates those time and cost issues. How? • Using a product that arrives from the factory already cured and set allows for continued production at the manufacturing location, particularly in the winter, when cold temperatures can delay or complicate the pouring of concrete.

• By using a thinner floor panel versus a 3-inch slab of poured concrete, the modules end up with reduced weight, requiring less coordination at the job site.

• Lighter-weight modules are less expensive to transport from a manufacturing facility to the final job site. Whereas pan-deck and poured concrete weigh around 40 pounds per square foot, USG Structural Panels weigh 5 pounds per square foot. This allows modular manufacturers to transport modules to a job site without incurring additional weight-related costs.

Thanks to their many benefits, USG Structural Panels are improving the speed and efficiency of modular construction, allowing engineers to create more effective and innovative building solutions – and meet the growing demand for modular construction – better than ever before.

For more information, visit: usg.com/modular.

© 2018 USG Corporation and/or its affiliates. All rights reserved.The trademarks USG, FIRECODE, H501, SHEETROCK, IT’S YOUR WORLD. BUILD IT., the USG logo, the design elements and colors, and related marks are trademarks of USG Corporation or its affiliates. Design No. H501 is available in its entirety at www.ulh501.com.

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USG Structural Solutions

IS POURED CONCRETE HOLDING YOUR PROJECT BACK? Choose a better, noncombustible alternative to poured concrete.

Learn more about USG Structural Panels at usg.com/structuralpanels

Š 2018 USG Corporation and/or its affiliates. All rights reserved.

The trademarks USG, the USG logo, the design elements and colors, and related marks are trademarks of USG Corporation or its affiliates.

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L

NUCOR ECOSPAN

ight. Economical. Versatile. These are just a few of the benefits that the Ecospan Composite Floor System brings to today’s commercial building market.

The Ecospan Composite Floor System is comprised of lightweight components working together to provide the structural strength to get the job done, but in a much lighter package than other competitive structural floor systems and products on the market today. Combined with a typical 2.5-inch concrete slab, this system will provide invaluable benefits to your next project.

Great Value When it comes to value, Ecospan provides big returns. A lighter system means the overall weight of the structure can be reduced, through its open-web structural components, and provides a lighter-weight composite design for elevated floors. In addition, lighter or fewer materials required to complete the project lessen the overall weight. Ease of installation reduces costly site time, and excellent sound and fire ratings help meet requirements with fewer materials. The components can contribute to LEED® certification for a project through the U.S. Green Building Council. The joists are made from 99% recycled steel and the deck is composed of 70% recycled steel. All of this adds up to more value for the money.

Low Impact, Long Life Increasing floor life while reducing environmental impact is an important combination in today’s commercial market. Thanks to

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technology advancements, new flooring options allow just that.

Ecospan Composite Floor System provides components with high strength-to-weight rations that allow for longer spans, shallow floor depths, greater rigidity, and enhanced performance. Slab thickness is typically 2½ inches with a total depth of 3½ inches. Compressive strength achieves 3,000 psi. The resulting versatility in floor space gives the owner and tenant greater options.

Chicago’s L Building boasts all the benefits of Ecospan’s Composite Floor System. Reaching six stories, this 120-unit multifamily apartment building creates an exceptional living experience thanks to its unique design and features. The lightweight system and the flush seat option allowed the use of a lighter structural wall system. This, in turn, helped minimize the overall cost of the building while still being able to provide the owner and tenants the features and benefits required for the project. One head-turning feature is the use of a retired CTA rail car as a lounge on the deck.

The Ecospan Composite Floor System is the smarter choice for your next structure, with the versatility to perform in low, mid, and high-rise structures. The lightweight and high strength design allows for longer spans, shallower floor depths, greater rigidity, and enhanced performance – all without sacrificing aesthetics. Quite simply, it is a better way to build.

For more information, 1-888-375-9787 please contact a local reprewww.ecospan-usa.com sentative or visit our website.

Elevate your structure with a groundbreaking flooring system.

The Ecospan Composite Floor System is the smarter choice for your next structure. Boasting an impressive combination of steel components with open web design, it has the versatility to perform in low, mid and high-rise structures. The lightweight and high strength design allows for longer spans, shallower floor depths, greater rigidity and enhanced performance – all without sacrificing aesthetics. Quite simply, it’s a better way to build.

Forge ahead of industry expectations with Ecospan. Call or go online and start building success today.

ECOSPAN IS THE BETTER CHOICE FOR: ®

- Apartments

Concrete Slab (by others)

Concrete Reinforcement (by others)

Vulcraft/Verco Steel Deck Shearflex HD screw

®

Vulcraft E-Series Steel Joist

The L, Chicago, IL

This six-story, 120-unit multifamily apartment building, with its unique design and features, creates an exceptional living experience. One distinctive feature of this building is the use of a retired CTA rail car as a lounge on the deck.

- Condominiums - Hotels and Resorts - Medical Facilities - Mezzanines - Military Housing - Office Buildings - Schools - Senior Living and Care Facilities - Student Housing and more.

Ecospan Composite Floor System Nucor Vulcraft National Accounts 6230 Shiloh Road, Suite 140 Alpharetta, GA 30005 678.965.6667 888.375.9787 www.ecospan-usa.com

CERTIFIED

S T R U C T U R E solutions

PROFILE

Pushing the Envelope Since 1933

ohmann and Barnard, Inc., serves both the Commercial and Residential markets as the leading developer and distributor of reinforcement, anchoring, and moisture protection systems for masonry.

Custom design and fabrication are longstanding hallmarks of Hohmann and Barnard’s ingenuity.

Recent developments include the 2X-HOOK for veneer anchors and adjustable joint reinforcement.

Featuring compressed and strengthened vertical legs, the 3/16-inchdiameter 2X-HOOK generates over 200 lbs.

in tension or compression. This exceeds BIA specifications by over 100%, even in wall cavities up to 7½-inch wide!

H&B has also developed the Thermal 2-Seal™️ Wing Nut Anchor that uses a STEEL REINFORCED, UL94 rated wing to create a thermal break at the insulation. By reinforcing the wing with a steel core, the anchor maintains integrity of the masonry veneer in the event of a fire. All-plastic wings melt, causing complete disengagement of the wire hook, and potential structural failure due to positive and negative lateral loads (wind loads).

For more information, please visit www.h-b.com/justthefacts.

Hohmann and Barnard is also committed to the environment, offering a complete line of environmentally friendly products for sustainable masonry structures. These include: masonry reinforcement and wire ties made from post-industrial recycled material, flashings and mortar control products made with recycled materials, VOC and HAP free air barrier products, and 1-800-645-0616 masonry cleaners manufactured without weanchor@h-b.com muriatic acid to be safer for workers and www.h-b.com the environment.

H O H M A N N & B A R N A R D, I N C.

JUST THE FACTS. ore

bef

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AFT

PASS

Independent testing clearly shows the 2-SEAL™ THERMAL WING NUT ANCHOR’s steel core intact and engaged on the left, and on the right ...

POSITIVELY NOTHING.

ore

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www.h-b.com/justthefacts

FAIL

Images from test #F4749.01-121-24, taken at 3rd party testing facility, INTERTEK-ATI.

S T R U C T U R E solutions 44-SS May 2018

ADVERTORIAL

H

HOHMANN AND BARNARD, INC.

S T R U C T U R E solutions

PV R O F I L E

AISC, 14th edition, ACI-318, and ASCE-7. VCmaster allows SEs to perform their own design calculations and combine them with fully editable templates from the extensive template library to create design calculations that fit the current project perfectly. Instead of hiding formulae in different spreadsheet cells, VCmaster uses natural mathematical notation, integrated text, or graphic formulae.

The software interprets and calculates formulae and variables automatically, having all related information stored in linked databases for easy access, thus allowing the creation of algorithms without any prior coding knowledge. VCmaster supports all of the mathematical functions of a pocket calculator, including any number of bracket levels or exponentials. The use of these features leads to easily readable documents that are understood by all involved, even in mixed teams.

VCmaster has many advantages: Achieving faster design times, thus increasing productivity, reducing risk due to clear calculations, and eliminating errors before they have major consequences. Even last-minute changes in load or design can be quickly and accurately adapted into current calculations.

VCmaster, with its combination of extensive calculation capabilities and elaborate text processing features, +49 711 518573-30 offers outstanding flexibility, contributing info@vcmaster.com significantly to lasting cost reduction while www.vcmaster.com helping to make better decisions faster.

S T R U C T U R E solutions 45-SS May 2018

ADVERTORIAL

Cmaster is a modern engineering software solution with an unparalleled range of features, supporting structural engineers not only when conducting complex calculations, but also when accurately documenting and efficiently communicating the intent behind them. In doing so, VCmaster has proven to be a reliable alternative to cumbersome spreadsheets.

VCmaster is developed with the underlying idea of meeting the individual needs of SEs, providing them with shareable documents that contain all project-related information, not just the results.

The software is available in three different editions. Whether SEs are undertaking small-scale projects or multi-locational tasks, they can choose the VCmaster edition providing the utmost support.

For example, the comprehensive Reports Edition includes smart features like Hybrid technology, supporting the creation of documents thousands of pages long; the universal t2W-interface, letting SEs integrate all external software outputs into one document; and state-of-the-art PDF-export for the final document (including PDF/A) as well as editors for small sketches or graphic formulae.

VCmaster provides a dependable cross-product concept, enabling SEs to incorporate all necessary external project data into the final structural design calculation and implement solid documentation, making design easier and more reliable than ever before.

All VCmaster editions are bundled with numerous calculation templates developed in the U.S. by American SEs according to

VCMASTER

S T R U C T U R E solutions

PROFILE

N

early fifteen years ago, a research group at the University of Toronto set out to explore how steel casting manufacturing could be leveraged to simplify and improve complex structural steel connections. Through the full-scale destructive testing of castings that they designed, those researchers saw firsthand how castings can provide dramatically improved structural performance and resilience over conventionally fabricated steel connections. They also recognized the architectural potential of the geometric freedom afforded by casting manufacturing.

Elegance in Design

A Variety of Solutions CAST CONNEX offers pre-engineered steel connection solutions ranging in applicability from strictly functional to those ideal for use in architecturally exposed structural steel (AESS). The company also engineers and supplies custom designed cast steel components.

Universal Pin Connectors™ (UPC) are sleek, clevis-type standardized fittings designed to connect to round hollow structural section (HSS) elements for use in AESS applications. The connectors are carefully sculpted to provide smooth transitional geometry that is otherwise unachievable using standard fabrication practices.

Architectural Tapers™ (ART) are hollowed, cast structural steel conical tapers also designed to connect to round HSS for use in AESS applications. Both UPCs and ARTs can be used on their own at the ends of steel columns, braces, struts, and ties, or used together,

lending a slenderer overall appearance to structural elements fitted with the connectors.

Diablo Bolted Splices™ (DBS) are cast steel fittings that enable unobtrusive field bolted splices in round HSS members. The fittings are designed such that the bolted connection is inboard of the outer diameter of the HSS. Splices made with DBSs can be sheathed in thin-gauge plate to completely conceal the splice or can be left uncovered for a more technical aesthetic.

Timber End Connectors™ (TEC) are clevis-type fittings designed to connect to the ends of heavy timber or glue-laminated structural elements loaded in predominately tension or compression for use in architecturally exposed applications.

High Strength Connectors™ (HSC) and Cast Bolted Brackets (CBB) are capacity designed connectors for use in Special and Ordinary Concentrically Braced Frames and Special and Ordinary Moment Frames, respectively. Both connector types are designed to eliminate the need for field welding, thereby improving quality and reducing the total installed cost of the structural steel frame. High Strength Connectors are also commonly used in AESS, as their use results in smaller gusset plates and because the connector’s curvaceous appearance is often preferred over slotted-HSS connections requiring net section reinforcement.

Scorpion™ Yielding Connectors (SYC) are modular, replaceable, standardized hysteretic fuses that provide enhanced ductility and improved performance in the retrofit of seismically deficient structures or for use in the Seismic Force Resisting System of new structures.

The system exhibits a full, symmetric hysteresis characterized by an increase in stiffness at deformations above design level. In multistory structures, this post-yield stiffening can decrease the likelihood of the formation of a soft story and results in a more uniform distribution of inelastic demand over the building’s height when compared to other yielding devises that exhibit a low post-yield stiffness.

High Integrity Blocks® (HIB) are heavy (up to 4-foot by 4-foot solid steel cross sections) weldable steel components that exhibit 50 ksi yield strength in all three directions of loading and through the full cross-section of the section. HIBs are ideal for use within the center of multi-axis loaded connections where lamellar defects in conventional rolled plate may compromise quality and strength of the connection or where the lamination of multiple steel plates to build up a section is not advisable due to the need to transmit forces orthogonal to the laminations.

CAST CONNEX also provides design-build services for Custom Cast Steel Components. Custom castings are designed to address project-specific needs and can provide economy in shop fabrication and field erection as well as create connection details that enable iconic architecture. The company’s turnkey services related to custom casting supply typically include industrial design and 3-dimensional modeling, 1-416-806-3521 engineering including finite element info@castconnex.com stress analysis, casting detailing, and www.castconnex.com manufacturing oversight.

S T R U C T U R E solutions 46-SS May 2018

ADVERTORIAL

Fueled by a passion to improve the safety and enhance the beauty of the built environment, two graduate students from that research group made it their life’s work to enable structural engineers to leverage castings in their building and bridge designs. And thus in 2007, CAST CONNEX was born. Since then, the company has put thousands of steel castings into service in hundreds of structures, establishing itself as an enabler of its collaborators’ innovative designs as well as an innovator in its own right.

Today, CAST CONNEX is a rapidly growing multinational organization, but at its core remains an almost zealous obsession with elegance in design. To CAST CONNEX, elegance encompasses everything from utility to aesthetics to manufacturability. “All of our solutions are developed with the aim to simplify steel fabrication and field installation, to beautify the spaces in which our components are used, and to improve overall structural performance and safety,” says company President and CEO, Carlos de Oliveira.

Company co-founder and Vice President Dr. Michael Gray is equally motivated. “In my ideal world, there would be more incentive to push buildings to higher levels of performance,” says Gray. “As an industry, we ought to move beyond code minimum; we need to elevate our standards. And not just for structural performance, but for aesthetics in design, too.”

CAST CONNEX

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PE R O F I L E

STRONGWELL

ngineers today have a plethora of choices when designing complex structures. For over 60 years, Strongwell has manufactured high quality pultruded fiber reinforced polymer (FRP) composites and structural shapes in replacement of metals and lumber. Strongwell’s FRP has proven itself in thousands of new construction projects, as well as refurbishment projects where FRP replaces materials at the end of their life cycles.

Project Highlights

Numerous Product Solutions Strongwell’s involvement in pultruded composites began with the production of fiberglass ladder rails in the 1950s and, since then, the company has produced well over a billion linear feet of that product. Strongwell was also the first to develop a line of standard structural shapes (EXTREN) in the 1970s. Since that time, the company has developed hundreds of proprietary and custom products sold all over the globe.

Some of Strongwell’s current fiberglass product lines include: structural shapes and plate, pultruded and molded grating, building panels, handrail, fencing, decking and planking, bridge components, and structural reinforcements, as well as numerous custom products.

The engineering community has designed and implemented these products within the architectural, construction, food, beverage, chemical, cellular, marine, energy extraction/ production, utility, hotel, infrastructure, recreational, military, transportation, and water/wastewater communities – just to name a few.

S T R U C T U R E solutions 48-SS May 2018

ADVERTORIAL

The project showcased on the opposite page was installed in 1988 on top of the tallest building in Orlando, Florida. Those turrets still crown the skyline today – 30 years (and over 100 tropical depressions and hurricanes) later. Although it may look like steel, every structural component in the pyramid-shaped turrets is made from Strongwell’s EXTREN® fiberglass structural shapes, and all connections utilize Strongwell’s EXTREN angle and plate, while being held together using Strongwell’s FIBREBOLT® fiberglass studs and nuts.

Because these turrets house emergency communications antennae, fiberglass was the perfect material choice. Strongwell FRP is transparent to radio and cellular waves. Strongwell holds L.A.R.R. approval for several of its products, which are regularly used to design and construct cellular screening.

On this project, the pre-fabricated structural components were shipped to the site, assembled on the ground, and lifted to the rooftop via crane. Workers were then able to bolt the fiberglass base plates to steel base plates on the roof. Since their installation, no maintenance has been required of the rooftop structure, save to check the tightness on base bolts after significant weather events.

Benefits

One key benefit to utilizing pultruded structural composites by Strongwell is that parts may be customized by modifying resin systems, colors, UV inhibitors, flame/smoke performance, and even the reinforcements to meet specific customer requirements.

Another key benefit to utilizing Strongwell’s FRP is the company’s comprehensive Design Manual. Engineers are usually familiar with designing using steel, wood, concrete, and other traditional materials – Strongwell’s Design Manual provides similar data necessary to design structures with its FRP composites. In addition, Strongwell provides design guides, specifications, fabrication worksheets, CAD blocks, a corrosion resistance guide, and dozens of case histories and other literature to assist engineers with the development of projects utilizing Strongwell materials. For those who are new to pultrusion (the manufacturing process used to manufacture pultruded products), Strongwell also offers an online training site.

Another major benefit is cost. While pultruded composites generally cost more than steel or wood, the installed costs can be as much as 40% lower than steel and life-cycle cost savings can produce even greater savings in the long term. Savings in skilled labor, downtime, permitting, and numerous other areas will often prove Strongwell FRP as a much less expensive (and better) option.

Strongwell’s staff consists of multiple registered professional structural engineers to design structures and/or provide technical design support to customers. The company’s mechanical engineers design equipment tooling, ASTM tests, and perform finite element analysis (FEA) on real or proposed pultruded parts. In addition, all of Strongwell’s pultrusion machines are designed in-house by electrical and systems engineers.

Strongwell is the world’s largest pultrusion company, operating almost 70 pultrusion machines and offering comprehensive design, testing, and fabrication capabilities within its 730,000 square feet of manufacturing space. Headquartered in Bristol, Virginia, Strongwell operates four facilities: Bristol and Abingdon, Virginia (most product lines); Chatfield, Minnesota (primarily handrail, grating, and fiberglass tool handles); and Apodaca, Mexico (ladder rail).

Strongwell’s pultruded composites are frequently tested internally, and by third parties, using the latest ASTM Test Standards to collect and share data and properties on a broad range of important performance measures. Examples of these tests include pin-bearing strength, tensile strength, flexural, compressive, izod impact, compressive sheer, barcol, water absorption, density, specific gravity, dielectric, weathering, tunnel, smoke, and flammability, to name few.

Strongwell composites are assembled in a very similar manner to their structural steel counterparts. Mechanical connections are common, primarily due to their wide adoption from the steel industry.

That said, composites are no stranger to bonded connections using epoxies, urethanes, or methyl methacrylates, or a hybrid approach using a combination of mechanical 1-276-645-8000 and bonded to ensure maximum info@strongwell.com short- and long-term performance of www.strongwell.com all connections.

DO IT ONCE MATERIALS THAT LAST

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SunTrust Bank Building, Orlando, FL Although it may look like steel, every structural component in the four 35' tall turrets that sit atop the tallest building in Orlando, Florida, is made from Strongwell fiberglass (FRP) structural shapes.

Strongwell FRP holds L.A.R.R. approval for use in transparent screening and enclosure systems.

VISIT WWW.STRONGWELL.COM/STRUCTURE TO LEARN MORE

STEEL

FIBERGLASS

STRONGWELL PRODUCTS PROUDLY

The World Leader in Pultrusion and Pultruded Fiberglass Structures & Shapes ISO-9001 Quality Certified Manufacturing Plants

276-645-8000 â&#x20AC;¢ info@strongwell.com www.strongwell.com

S T R U C T U R E solutions

PF R O F I L E

AMERICAN CONCRETE INSTITUTE The awards program relies upon the global network of ACI chapters and international partners to nominate award-winning projects in the following six categories: • Low-Rise Buildings • Mid-Rise Buildings • High-Rise Buildings • Infrastructure • Repair and Restoration • Decorative Concrete The most recent Excellence in Concrete Construction Awards recipients were ACI members celebrate concrete excellence at announced on October the Institute’s Fall 2017 Convention. Mark 16, 2017. Global concrete your calendars to attend the next awards excellence was celebrated, celebration on the evening of October 15, and the highest honor was 2018, in Las Vegas, NV, USA. presented to the R·torso·C residence, in Tokyo, Japan, which demonstrated excellence in concrete innovation and technology. Additional recipients include: • Repair & Restoration o 1st Place: Market Street Parking Garage Restoration, in Wichita, KS, USA. o 2nd Place: Chillon Viaducts, in Veytaux, Switzerland.

• Mid-Rise Buildings o 1st Place: Denver International Airport - Hotel Transit Center in Denver, CO, USA. o 2nd Place: Columbia University Medical and Graduate Education Building, in New York City, NY, USA. • Decorative Concrete o 1st Place: Ryerson University Student Learning Centre, in Toronto, ON, Canada. o 2nd Place: Lock 8 Skate and BMX Park, in Port Colborne, ON, Canada.

• Low-Rise Buildings o 1st Place: R·torso·C, in Tokyo, Japan. o 2nd Place: Frick Environmental Center, in Pittsburgh, PA, USA. • High-Rise Buildings o 1st Place: Embassy Lake Terraces, in Karnataka, India. o 2nd Place: Premiere on Pine, in Seattle, WA, USA. • Infrastructure o 1st Place: Johnson County Gateway in Overland Park, KS, USA. o 2nd Place: Winona Bridge, Winona, MN, USA. ACI is in the process of reviewing 2018 entries and will announce winning projects during the ACI Excellence in Concrete Construction Awards Gala on Monday, October 15, 2018 in Las Vegas, NV, at the ACI Concrete Convention & Exposition.

This will be the fourth annual awards program, and winning projects will join previous winners from France, Italy, Japan, and throughout the world. Entries for the 2019 awards will be accepted beginning in Fall 2018.

For more information 1-248-848-3700 regarding ACI membership, acicustomerservice@concrete.org education, or concrete innovawww.concrete.org tion, please visit our website.

S T R U C T U R E solutions 50-SS May 2018

ADVERTORIAL

ounded in 1904 and headquartered in Farmington Hills, MI, the American Concrete Institute (ACI) is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational & training programs, certification programs. ACI provides proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete. The Institute has over 95 chapters, 110 student chapters, and nearly 20,000 members spanning over 120 countries.

ACI is the premiere, global community dedicated to the best use of concrete. With enhanced benefits starting in 2018, ACI membership provides information on engineering and construction practices worldwide – providing engineers, contractors, and concrete professionals the opportunity to save time and money while increasing productivity and competitiveness.

All ACI individual members now receive free digital access to the Institute’s 200+ practices – including all guides and reports – plus free shipping in the United States. Additionally, members will have the added benefit of using two new substantial discounts: • Digital access to ACI’s 50 active codes and specifications – this includes all ACI’s code requirements on structural, environmental, residential, repair, and more, including current and historic versions; and • Access to the new, annual subscription of ACI University’s live webinars and on-demand courses.

These new benefits are in addition to current benefits – Concrete International magazine; ACI Materials Journal; ACI Structural Journal; discounts; ACI University course tokens; access to the ACI Career Center; inclusion in the ACI Member Directory; and the opportunity to join committees.

ACI also offers online professional education that provides continuing education credit through ACI University.

ACI University is a global, online learning resource, providing on-demand access to a wide range of topics on concrete materials, design, and construction, appealing to everyone from testing technicians to practicing engineers.

ACI most recently announced the launch of an all-access subscription to ACI University webinars and R·torso·C, Tokyo, Japan is on-demand courses. The new awarded highest honors in 12-month subscription includes access the 2017 ACI Excellence in to all ACI live webinars and ACI’s 175+ Concrete Construction Awards on-demand courses. Topics include admixtures, codes, cracking, design, durability, and much more.

Prices for the all-access subscription start as low as $99.00.

Now more than ever, concrete design and construction projects must integrate creative techniques and technologies to keep up with ever-evolving economic, environmental, and aesthetic demands. In 2015, ACI introduced the ACI Excellence in Concrete Construction Awards to provide a platform to recognize concrete projects from around the world at the forefront of innovation and technology.

ACI 212.3R-10

ACI University All-Access Digital Subscription

Report on Chemical Admixtures for Concrete

Reported by ACI Committee 21

The American Concrete Institute announces a new all-access subscription to ACI University webinars and on-demand courses. This 12-month subscription includes all ACI monthly webinars and ACIâ&#x20AC;&#x2122;s 175+ on-demand courses. Multi-user options are also available. Visit www.aciuniversity.com to subscribe

Prices as low as $99.00

175+ On Demand Courses | Monthly Webinars | Multi-User Options | 55+ Different Topics

www.ACIUniversity.com

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PI R O F I L E

n 1987, Dlubal Software was founded by George Dlubal in the remote town of Harsewinkel, Germany. Over the last 30 years, the company has grown to more than 200 employees in six different office locations. In July of 2015, the Philadelphia, PA, office was established to emerge as a competitive player in the North American structural engineering software market.

The 3D finite element program, RFEM, is the main attraction among the Dlubal Software lineup. A nonlinear program capable of not only 1D member analysis but also 2D and 3D elements such as plates, shells, and solids. In a market full of similar programs and other competitors, Dlubal knew that RFEM had to stand out from the crowd.

The company takes extreme pride in their user-friendly and intuitive programs. Although the capabilities of the software can explore the extreme depths of nonlinear structural analysis, the modeling ease, workflow, and organized data input and results will not leave engineers in need of endless training to learn the program. In a matter of hours, along with the technical guidance of Dlubal’s technical support engineers and online resources, users will have a firm grasp on how to generate and analyze a structural model.

A Modular System

Brock Commons CLT Floor Panels in RFEM (© www.fastepp.com ).

transparent any software can provide. Complete with listed variables and code references for all equations used, engineers have little doubt on how the program is ultimately determining final code checks. Don’t discount Dlubal when it comes to steel and concrete design; they do it Kauffman Center for the Performing Arts well, but they also rec- (© www.novumstructures.com ). ognize this is the most competitive material design when it comes to structural analysis software.

Niche Markets Where RFEM continues to thrive are the niche markets where other software has yet to explore. With additional design modules for aluminum (ADM), timber (NDS), cross-laminated timber (NDS), glass (stress design), and the fabric and form-finding procedure is where RFEM singly-handedly stands out. Engineers do not have an efficient solution for the design of these various materials. As projects become increasingly more complex and deadlines become increasingly shorter, a more advanced structural analysis program such as RFEM is needed to move forward and stay ahead of the competition.

One of Dlubal’s most valuable clients, Novum Structures LLC, Menomonee Falls, WI, utilized the software to aid in the design of the renowned Kauffman Center for Performing Arts located in Kansas City, MO. The glass atrium is the signature feature of this building (dimensions L x W x H: 317 x 73 x 70 feet) which connects the main entrance to both performance venues. The glass facade and the glass skylight are supported entirely by the cable structure. This design was conceived as a cello’s strings fanning over a bridge and fretboard. The structural analysis of the atrium steel-glass structure was performed using Dlubal Software.

Another long-time and valued client Fast + Epp, located in Vancouver, Canada, has utilized RFEM’s cross-laminated timber design to complete the 18-story mass timber hybrid student residence Brock Commons located at the University of British Columbia in Vancouver. After its completion in 2017, it remains the tallest mass timber hybrid building in the world at 174 feet high. Individual floors were modeled in RFEM with the RF-LAMINATE add-on module to best determine the flexure/shear demands in the panels, as well as the serviceability performance of the two way, pointsupported system.

In summary, Dlubal Software aims to integrate the most powerful yet user-friendly FEA program with today’s engineers to meet the challenges of modern-day structural engineering. Building heights are increasing, materials are no longer limited to steel and concrete, and designs now include complex curva1-267-702-2815 tures and asymmetric layouts. Structural info-us@dlubal.com engineers need a software that can not only www.dlubal.com keep up with the demand, but far exceed it.

S T R U C T U R E solutions 52-SS May 2018

ADVERTORIAL

RFEM works with the modular concept system. Any design or advanced capabilities beyond the static analysis provided in RFEM are available with the vast array of add-on modules. The add-on module RF-MAT NL, for example, allows for consideration of nonlinear material behavior in RFEM. This includes isotropic plastic, isotropic nonlinear elastic, isotropic thermal elastic, and many more for 1D, 2D, and 3D elements. The module RF-STABILITY analyzes the stability of the structure and calculates critical load factors and corresponding stability modes. When many other programs cannot take into consideration buckling behavior of member, plate, and shell elements, RFEM steps up.

The add-on modules for steel and concrete design apply code provisions per AISC and ACI to determine unity checks and reinforcement layout. Result output in these modules is among the most

DLUBAL SOFTWARE

RFEM 5 FEA Structural Analysis Software

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Structural Analysis & Design Software Dlubal Software, Inc.

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Tel.: (267) 702-2815

info-us@dlubal.com

S T R U C T U R E solutions

PK R O F I L E

For example, the Los Angles Building Code requires a minimum of three accelerographs to be deployed at the base, middle, and top of a structure over ten stories or six stories with an aggregate floor area of 60,000 square feet or more. The three instruments are usually placed in a vertical stack and interconnected for common triggering and timing.

Features and Benefits • Low cost and low maintenance • Compliant with Los Angeles Building Code • Cost-effective solution that can satisfy today’s most demanding applications • Remote alerting capability for system event or auto-diagnostic failure • The iCOBI 3 system includes digitizers, battery systems providing 48 hours of autonomy, and communications equipment. Users only need to supply the CAT-6 interconnection cable and local AC power.

Through innovations that matter, Kinemetrics is the premier partner for those who seek actionable 1-626-795-2220 solutions that take seismic research and www.kinemetrics.com resilience further, faster.

S T R U C T U R E solutions 54-SS May 2018

ADVERTORIAL

inemetrics is committed to excellence in delivering the most trusted earthquake monitoring products, solutions, and services in the world today. Since 1969, Kinemetrics and its subsidiaries have been the global market leaders in designing technologies, products, and solutions for monitoring earthquakes and their effects on people and structures. Many of our products are the de facto standards to which other products were and are compared.

A shining example of these products is the iCOBI 3 Building Code Compliant Seismic Monitoring Accelerograph System! The iCOBI 3 is an Internet Ready, Code Compliant Building Instrumentation System for seismic monitoring. Seismic monitoring systems provide valuable data and information on the behavior of buildings, leading to improved understanding and better design codes.

For these reasons, many municipalities (e.g., City of Los Angeles, CA USA) require seismic instrumentation or offer benefits such as reduced inspection time as part of a building occupancy resumption program (e.g., BORP San Francisco, CA USA).

KINEMETRICS

S T R U C T U R E solutions

ADVERTORIAL

PROFILE W

illiams Form Engineering Corporation has been providing threaded steel bars and accessories for rock, soil and concrete anchors, post tensioning systems, and concrete forming hardware systems in the construction industry for over 95 years.

Williams’ pre-stressing / post tensioning 150 KSI All-ThreadBars are high tensile steel bars available in seven diameters from 1inch (26 mm) to 3 inches (75 mm), with guaranteed tensile strengths to 969 kips (4311 kN). Bars are cold rolled threaded to close tolerances under continuous monitoring procedures for quality control. Threads for Williams 150 KSI bar are specially designed with a rugged thread pitch wide enough to be fast under job site conditions and easy to assemble. They also have a smooth, wide, concentric surface suitable for torque tensioning.

WILLIAMS FORM ENGINEERING

This combination offers tremendous installation savings over inefficient, hot rolled, non-concentric thread forms. The 360° continuous thread deformation pattern has the ideal relative rib area configuration to provide excellent bond strength capability to grout or concrete, far better than traditional reinforcing deformation patterns. Threads are available in both right and left hand in all diameters. All 150 KSI All-Thread-Bar fasteners are machine threaded (no cast threads) to specific tolerances for precision adjustments.

All fasteners are designed to develop 100% of the bar’s ultimate strength, meeting all criteria set 1-616-866-0815 forth for anchorages by the Postryan@williamsform.com Tensioning Institute and ASTM www.williamsform.com A-722 specifications.

one source FOR MICROPILE

QUALITY SYSTEMS LARGE BAR . HOLLOW BAR . MULTI-BAR

reliable | durable | versatile

Large Bar Micropiles: • Excellent choice for underpinning or emergency repairs All-Thread Bar — can be installed in virtually any ground condition with with Steel Casing minimal vibration and disturbance to existing structures.

Geo-Drill Injection Bar • Right-handed threaded Grade 75 All-Thread Rebar in #14 – #28 along with a selection of reducer couplers that can adapt to space together any larger size bar to any small size.

• Grade 80 to 100 All-Thread Rebar, as well as 150 ksi All-Thread Bar (as alternative for micropile design application upon request).

Williams Multi-Bar Micropile System

Hollow Bar Micropiles: • Accepted by the FHWA in the Micropile Design and Construction Guidelines Manual, Hollow Bars are being used increasingly for micropile applications as the reinforcement bar choice in collapsing soil conditions because of their increased bond stress resultant from the simultaneous drilling and grouting operation.

• Using sizes from 32mm – 76mm, these bars offer up to 407 kips of strength, up to 3.88in2 of cross sectional reinforcement area, and their selection modulus provides considerable bending resistance.

Multi-Bar Micropiles: • Used for attaining ultra-high load carrying capacity. High-rise office buildings and condos are construction examples where such high load carrying micropiles (mini-caissons) are used.

• Designed to specific contractor specifications and shipped to the jobsite fabricated in durable cages for quick installation.

Construction photos courtesy of Williams Form Engineering Corp.

Williams Form Engineering Corp. has been a leader in manufacturing quality products for the customer service for over 80 years.

Belmont, MI 616.866.0815

Lithia Springs, GA 770.949.8300

Kent, WA 253.854.2268

San Diego, CA 858.320.0330

Portland, OR 503.285.4548

London, ON 515.659.9444

Golden, CO 303.216.9300

Collegeville, PA 610.489.0624

18104_WILLIAMS_Micropile_Structures_half_page_ad.indd 1

System illustrations courtesy of Williams Form Engineering Corp.

For More Information Visit:

williamsform.com

S T R U C T U R E solutions 55-SS May 2018

3/15/18 11:00 AM

S T R U C T U R E solutions

PROFILE

SIMPSON STRONG-TIE

Residential Structural Solutions

H

ere are some of the latest product solutions that we have engineered and tested to address your specification needs.

Structural Connectors

Decorative Hardware with Structural Strength The Outdoor Accents® decorative hardware line is ideal for outdoor structural projects and has been fully tested to resist wind and seismic loads. The line consists of code-listed connectors and fasteners made from ZMAX galvanized steel with a black powdercoat finish for corrosion protection from outdoor exposure. Our complete line includes structural elements (strap ties, angles, fasteners and post bases) along with decorative accents (side plates and decorative washers) that together add both strength and beauty to outdoor structures.

The innovative Outdoor Accents structural wood screw also features our SawTooth point. The patent-pending hex-head washer for use with the SDWS structural screw offers the look of a bolted connection but installs faster and more easily.

The Outdoor Accents line has recently been expanded, so it now comprises connectors and fasteners to build with 4x, 6x, 8x and 10x lumber.

To learn more about these and other 1-800-999-5099 new products, visit our website or call www.strongtie.com and speak to a representative.

Structural Fasteners In 2018, Simpson Strong-Tie is re-introducing many of its StrongDrive® structural fasteners, which now feature a patented SawTooth™ point. The newly redesigned structural screws are already known for their strength and durability, and with the new serrated threads and vertical knurls, fastener driving is quicker and easier with reduced torque. Screws that feature the new SawTooth point are the Strong-Drive SDWS Timber, SDWS Framing, SDWS Log, SDWH Timber-Hex, SDWH Timber-Hex HDG, SDW Truss-Ply and SDW EWP-Ply. The code-listed Strong-Drive SDWH Timber-Hex screw is ideal for structural wood-to-wood and engineered wood connections and

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ADVERTORIAL

The new patent-pending MPBZ is the first off-the-shelf post base specifically designed to provide moment resistance for columns or posts. An innovative overlapping sleeve design encapsulates the post, helping to resist rotation around its base. Available for 4x4, 6x6 and 8x8 posts, the MPBZ is ideal for outdoor structures such as carports, fences, and decks. Built-in standoff tabs provide the required 1-inch standoff to resist post decay while eliminating multiple parts and assembly. Available in ZMAX® as a standard finish to provide corrosion resistance.

The new DG fire wall hanger is the next generation of our drywall hanger series. The new series features three models of top-flange hangers (DG/DGH/DGB) that connect floor trusses and joists to wood stud walls. It is ideal for multi-family, multi-level wood building construction and easily installs on a two-hour wood stud fire wall (e.g., Type III construction) during framing – BEFORE the drywall. The joist hanger gives the completed assembly the ability to function as a continuous fire-rated wall. All three fire wall hangers have been tested according to ASTM E814 and received F (flame) and T (temperature) ratings for use on one or both sides of the wall. These ratings verify that the DG/DGH/DGB hangers do not reduce the two-hour fire wall assembly rating.

general-purpose fastening applications where a hex-head drive is preferred. The SawTooth point ensures fast starts, reduces installation torque and eliminates the need for pre-drilling in most applications.

In addition, the fastener boasts a bold thread design for superior holding power. Underhead nibs offer greater control when seating the head, and a double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making the SDWH TimberHex suitable for exterior and preservative-treated wood applications.

Recently, Simpson Strong-Tie has also introduced load-rated versions of the #10, #12 and #14 sizes of the popular Deck-Drive™ DWP Wood SS deck screw for use in decks, docks, and boardwalks built near water or in other corrosive environments.

The grand opening of moment resistance.

Expand your options for designing open outdoor structures with the new, patent-pending MPBZ moment post base—now available in 4x, 6x and 8x sizes. This innovative connector provides optimal strength at the base of columns and posts to resist lateral loads at the top—reducing the need for knee bracing.

MPBZ44

MPBZ66

MPBZ88

© 2018 Simpson Strong-Tie Company Inc. MPBZ17-S

Learn more about the Simpson Strong-Tie ® MPBZ by visiting go.strongtie.com/mpbz or calling (800) 999-5099.

Pergola design by foreverredwood.com

S T R U C T U R E solutions

PROFILE TAYLOR DEVICES

A

cross the globe, current building codes only require that new buildings be designed for collapse prevention. They do not require “performance-based designs” that greatly improve performance during an earthquake. It is assumed that a new building will perform well during earthquakes and allow residents to inhabit them immediately following a major seismic event.

From a Space Program Hall of Fame induction to one of the tallest, mixed-use buildings in San Francisco, Taylor devices continues to provide the most efficient, effective and innovative structural protection products on the planet.

716 694 0800 | seismicdamper.com

S T R U C T U R E solutions 58-SS May 2018

1-716-694-0800 www.seismicdamper.com

ADVERTORIAL

The height of structural protection.

Literally.

However, a brand-new building built to code could be seriously damaged, or collapse, making the structure useless after an earthquake. If more people knew this, lives could be saved, and replacement of damaged property could be minimized.

Taylor Devices’ technology can limit or prevent such damage and make buildings perform to their full potential. This technology takes advantage of the same concept used on every car suspension in operation today to smooth out the bumps and make our rides safe. Other technology, such as yielding members, cannot provide equivalent performance. These devices are meant to yield in a major earthquake, so the building will have permanent damage and the devices would need to be replaced at an enormous cost.

Imagine the backlash from residents, lawyers and insurance companies upon discovering that this was preventable.

Taylor dampers are designed to be maintenance-free and to last the life of the building, without requiring replacement after an earthquake. If more structural engineers knew how to model dampers, and were willing to analyze them in new structures, this could lead to saving lives and reducing rebuilding costs after an earthquake.

An exceptional example of Taylor’s seismic dampers is the impressive San Francisco highrise, 181 Fremont. Billed as one of the “world’s most innovative and durable structures,” Taylor Devices was tasked with working with the structural engineers to solve the challenges posed by the 802-foot building. In total, seismic and wind protection is provided by 32 Taylor dampers, each rated at 225 tons of force.

The dampers are nine feet long, 15 inches in diameter, and weigh as much as a compact automobile. Occupant comfort requirements dictated that the dampers continuously stroke, under even small wind motions, with almost zero seal friction. This required use of the company’s patented metal bellows seals, initially developed by Taylor Devices for NASA. Scaling the small spacecraft parts up to sizes required for 181 Fremont was a challenge, but the results proved excellent. The metal bellows seal design provides a maintenancefree product designed for decades of service, while continuously stroking under minor winds or a major earthquake.

S T R U C T U R E solutions

PROFILE

A

beds for ceramic tile, for bonding Portland Cement plaster and stucco mixes, and to bond to such surfaces as brick, block, tile, marble, metal, glass block, soundly adhered paint (non-soluble in water), and silicone.

Our original chemical, concrete bonding agent incorporates polyvinyl acetate homopolymer in a patented formulation and has been specified in major construction projects around the globe.

If you have not yet specified Weld-Crete, we encourage you to reach out to us directly to learn more. We will answer any questions you may have so that you feel completely confident spec’ing our product.

To our current engineers and architects who consistently specify Weld-Crete, we thank you for your loyalty and look forward to seeing Weld-Crete specified in your projects for years to come.

For over sixty years we have set the standard for bonding agents and take great pride in the reliability, consistency, and overall product quality that Weld-Crete offers. This, along with our unparalleled customer service and support, and our desire for every customer to be completely satisfied, is why Larsen Products Corp. has been an industry-trusted source by architects 1-800-633-6668 and engineers worldwide since 1952. claire@larsenproducts.com For more information please visit www.larsenproducts.com our website or contact us directly.

Weld-Crete®—The pale blue bonding agent with over 60 years of superior performance in the field.

Simply brush, roll or spray Weld-Crete® on to concrete or any structurally sound surface. Then come back hours, days or a week later and finish with new concrete, stucco, tile, terrazzo, other cement mixes or portland cement plaster. Plus Weld-Crete’s® low VOC content significantly reduces airborne pollutants that affect health and the environment.

Originators of leading chemical bonding agents… worldwide since 1952

800.633.6668 www.larsenproducts.com

S T R U C T U R E solutions 59-SS May 2018

ADVERTORIAL

high-performance, low VOC concrete bonding agent, Weld-Crete® bonds new concrete, stucco, tile setting beds, and terrazzo to any structurallysound surface, be it on the interior or exterior. WeldCrete’s open time lets you bond to concrete shear walls when needing a time lapse between the application of the bonding agent, the placement of reinforcement steel, placement of formwork, or the placement of concrete.

Conveniently, Weld-Crete can be “painted on” in a single application for a wide range of time-lapses. You can save time on the job by painting on WeldCrete in a single application, prior to concrete placement. Use Weld-Crete’s broad open time (1 hour to 10 days after applied) to your advantage in bonding to concrete shear walls; when you need a time lapse between application of bonding agent; placement of reinforcing steel; placement of formwork and placement of concrete. Weld-Crete is also used for bonding setting

LARSEN PRODUCTS

S T R U C T U R E solutions

PF R O F I L E

using our AASHTO Grade bearing pad materials – either as a standalone bearing or as part of a slide plate assembly.

Embeds and Fabrication: Throughout our history, we have assisted contractors and fabricators by providing more than slide plates and bearing pads. Our steel fabrication capabilities allow us to provide both one-stop-shop convenience and quick-turn custom steel fabrication.

New Products: We are excited to meet the construction industry’s demand for innovation in structural materials. We have worked hard to expand our product offerings to include several new types of materials. Our GRM Thermal Break Pads improve the thermal properties of a structure without compromising strength and stability and are manufactured from the highest quality composite materials.

Polyethene (UHMW and HDPE) is now being specified for use in structural connections as a low cost, but still chemically resistant and physically tough, isolator. PEEK is also seeing use as a structural bearing in extreme load and temperature scenarios.

Please visit our website or start a conversation with an email to find more information about our history, 1-936-441-5910 projects, and solutions.

We look forward to putting our experi- eng@grmcp.com www.grmcp.com ence and expertise to work for you!

S T R U C T U R E solutions 60-SS May 2018

ADVERTORIAL

or over 50 years, GRM Custom Products has worked with engineers, steel fabricators, and contractors to provide structural products and solutions on a wide variety of construction projects.

Our history of providing superior products and service to the construction industry is the foundation on which we stand as we look to the future. Here is a brief look at some of the ways we can help your design reach its full potential.

Slide Plates: As the exclusive fabricator of Fluorogold® Slide Plates in North America, we manufacture all of our Fluorogold and GRM Slide Plates to meet the requirements of our customers’ project specifications and schedules. Any design with connections requiring expansion can benefit from using slide plates. Whatever the application, our Fluorogold and GRM Slide Plates have a long and proven track record of reliable, maintenance-free operation. We maintain stock in a wide variety of PTFE and Graphite materials.

This gives us the opportunity to offer not only finished slide plate assemblies, but also bulk PTFE and Graphite in sheet or roll form at competitive prices.

Bearing Pads: With our experience in manufacturing a wide variety of structural bearing pads, we can help bring your design to life.

Rotation, vibration, and thermal expansion can be accommodated

GRM CUSTOM PRODUCTS

S T R U C T U R E solutions

PI R O F I L E

and vibration isolation products in the global marketplace with the most cost-effective products offering more features, greater performance, and improved ease of use. If you are unsure whether an ITT Enidine product will meet your application requirements, please visit our website or, better yet, contact us.

About ITT Enidine Inc. ITT Enidine Inc. has been a world leader in the design and manufacture of standard and custom energy absorption and vibration isolation solutions since 1966. ITT Enidine products can be found throughout the global marketplace within the industrial, aerospace, defense, and rail industries. Product ranges include seismic dampers, small and large shock absorbers, rate controls, air springs, wire rope isolators, heavy industry buffers, and emergency stops. Enidine is widely recognized as the preferred source for energy absorption and vibration isolation products.

As a market leader in multiple global industries, we have a rich heritage of delivering products that are reliable, durable, and efficient. Our adaptable technologies are engineered to meet the growing needs of todayâ&#x20AC;&#x2122;s global marketplace, and we focus on working closely with our custom- 1-800-852-8508 ers to solve their most difficult industrialsales@enidine.com challenges. No matter the applica- www.itt-infrastructure.com tion or the industry, we solve it.

S T R U C T U R E solutions 61-SS May 2018

ADVERTORIAL

TT Enidine engineers focus on solving complex seismic application challenges worldwide. Our experts are innovative and responsive to partners, assisting them through each step in their design processes.

Whether its wind load, thermal motion, or seismic events, we offer the widest range of standard and custom energy absorption and vibration isolation products for global infrastructure applications that demand the highest level of quality, on time delivery, service, and support.

At ITT Enidine, our customers choose us over the competition because we offer innovative and differentiated products.

All of our products are engineered and manufactured in-house with lean manufacturing processes and expansive testing capabilities, giving you fast reliable service to meet your critical infrastructure application needs. Our customers stay with us because of our global reach, superior service, and focused commitment to their business goals.

Through proper care and maintenance, ITT Enidine products will give you a lifetime of exemplary performance and service. We continually strive to provide the widest selection of energy absorption

ITT ENIDINE

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ADVERTORIAL

PF R O F I L E

rom being among the tilt-up industry’s earliest advocates and founding members of the Tilt-Up Concrete Association to our industry-leading engineering excellence and innovation, Dayton Superior is the expert contractors trust for high-performance products and unmatched service. We provide the support you want throughout your entire project – from floor slab to panel lifting through finishing and maintenance.

We make your job easier because we make it easy to work with us.

We manufacture the strongest, safest, and highest quality products available in the tilt-up market. We take the late-night phone call, answer the weekend email, and have technical representation on site when you need it. We know few things are as important to you as staying on schedule, and the reliability, predictability, and availability of your vendors are critical elements that have significant impacts on your project schedule. We do all we can to adhere to your schedule and exceed expectations.

From eliminating challenges early on in tilt-up construction design to nurturing a collaborative environment for contractors and designers, Tilt Werks® is a proven solution for the tilt-up industry.

It is a BIM system that works with engineering design software to

DAYTON SUPERIOR provide an enhanced level of efficiency for design. This allows the various sections of the process (tilt-up panels, steel framing, etc.) to do what they do best. Each section can gain benefits from the other, leading to the development of a more complete BIM system and continuing the core idea behind Tilt-Werks – a centralized location for ALL the building data.

In tilt-up construction, the quality of the slab is doubly critical to the success of the project. Not only must it have all the qualities for flatness, finish, and durability required for the eventual heavy use it will experience well into the future, it also must achieve all the practical and aesthetic requirements of a casting bed for the wall panels that will be cast upon it. Dayton Superior has a variety of chemical and accessory products to meet your project requirements and support your construction process! From keyway forms to steel dowel assemblies for load transfer… to chemicals to cure, seal, dustproof, and densify the slab for long-term durability… to panel brackets and rustication strips and bond breakers to achieve the required dimensions and designs for the panels cast on it… Dayton Superior provides the solutions that 1-847-391-4972 set the stage for your project success. www.daytonsuperior.com

TILT-UP CONSTRUCTION SOLUTIONS

Dayton Superior has been synonymous with quality, safety, professional service, and an unmatched tilt-up product portfolio.

TILT-WERKS.COM

INFO@TILT-WERKS.COM

SCALE NEW HEIGHTS IN PRECISION AND EFFICIENCY Tilt-Werks® is a Unique, Powerful New Construction Technology • Developed specifically for the tilt-up concrete construction industry • Web based service — Data can be accessed and edited from anywhere, anytime

WWW.DAYTONSUPERIOR.COM/SOLUTIONS/TILT-UP

S T R U C T U R E solutions 62-SS May 2018

S T R U C T U R E solutions

PROFILE

A Leader in Sustainable Wood Solutions

ADVERTORIAL

M

assive timber is increasingly seen as having a very bright future. Friendly to the environment and a great performer, wood makes an obvious choice for low-energy buildings or passive houses. While the “green” factor has played a decisive role to date, the economic benefits are becoming ever clearer.

With over 2,000 construction projects using massive timber in North America over the last decade, Nordic Structures is a leader in sustainable construction. It should be pointed out that the vast majority of projects to date have been developed by private promoters, which attests to the competitiveness of the product.

A trusted partner, Nordic Structures stands out by its integrated offerings, from FSC-certified forest to construction site. With over 50 building and infrastructure professionals, well versed in design, optimization, and engineering, our staff can support project teams from the ideation of a building all the way to the precise and rapid execution and installation of the structure.

Over the years, Nordic Structures has been a pioneer, with sports facilities for indoor soccer and hockey, institutional projects of all types, bridges on public and private roads, industrial buildings for manufacturing plants or aircraft maintenance, in addition to being at the forefront of great innovations in erecting multi-unit buildings, with structures of up to 12 floors in height, using 100% massive timber.

NORDIC STRUCTURES Many projects bear witness to the effectiveness of massive timber construction – the rebuilding of the seismically active zone around L’Aquila in Italy, for example. Of all building materials, wood boasts the best weight-to-resistance ratio, making it great on challenging terrain or for roof extensions.

In addition, massive timber is incredibly safe and stable in case of fire as it burns slowly; a carbon layer forms on the surface and impedes combustion. Its resistance is relatively unaffected by heat.

This is not the case with so-called “incombustible” materials. Since burning rates are known, designers can specify the minimum dimensions needed to maintain the mechanical performance of elements, in accordance with the degree of fire resistance required.

The complete array of products offered by Nordic Structures includes glulaminated wood beams and pillars and cross-laminated panels. All these products are made with black spruce, a variety recognized for its 1-518-869-9116 dense fibers which grant it enviable jmdubois@nordicewp.com stability and structural capabilities. www.nordic.ca

competitive. efficient. sustainable.

S T R U C T U R E solutions 63-SS May 2018

NOR DIC S TRUC TURE S DEL I VERS

nordic.ca

S T R U C T U R E solutions

PROFILE

R

ISA has been developing leading-edge structural design and optimization software for over 30 years. Our products are used by 24 of the top 25 US design firms in over 70 countries around the world for towers, skyscrapers, airports, stadiums, petrochemical facilities, bridges, roller coasters, and everything in between. The seamless integration of RISA-3D, RISAFloor, RISAFoundation, RISAConnection, RISA-2D, and RISASection creates a powerful, versatile, and intuitive structural design environment, ready to tackle almost any design challenge.

The following recent case studies illustrate the versatility of our software.

Project: Pterodactyl Office Building

Project: Phillips 66 Freeport LPG Export Terminal Building Client: Phillips 66, Houston, TX Structural Engineer: Burns & McDonnell, Kansas City, MO The Phillips 66 Freeport LPG Export Terminal, located on the Gulf of Mexico in Freeport, TX, is a 100-acre facility used for the export of over 4 million barrels of liquefied petroleum gas per year. The project utilized modular steel pipe rack Courtesy of Phillips 66

structures that could be built offsite so that the compressed project schedule could be met. Each modular unit was analyzed and designed using RISA-3D for gravity, hurricane force wind loading, and “motion” loading conditions that would arise during transport at sea. Due to the facility’s location on the water, the finished modules were shipped in on barges and could be larger than what trucks could typically accommodate. This led to the largest modules measuring at 40 feet tall, 32 feet wide, and 110 feet long and weighing in at 170 tons.

“RISA-3D’s interface is more user-friendly than any of the other programs that we use, allowing a new engineer to pick it up with very little instruction, and then build and analyze a complicated structure.”

In addition to the pipe racks, three 200-foot pipe bridges were needed to span the existing levee. These bridges were also designed in RISA-3D and utilized a modular system which allowed the units to arrive on-site fully assembled, including all required pipe racks. In total, 6150 tons of steel were used, and the schedule of the project was significantly reduced as a result of the modular construction techniques that were utilized.

Project: Pinnacle Bank Arena Building Client: SMG, West Conshohocken, PA Structural Engineer: Buro Happold Consulting Engineers, New York, NY Specialty Structural EOR (CFS Framing): Excel Engineering Inc., Fond du Lac, WI Pinnacle Bank Arena serves as the foundation for the $344 million West Haymarket Redevelopment Project in Lincoln, NE. The arena regularly hosts concerts, performances, and other live events in addition to serving as the home for the University of Nebraska basketball teams. The main structural components of the 470,400 square-foot arena consist of a concrete structure, wrapped in metal panel and Courtesy of Excel Engineering Inc. glass curtain wall façade.

“The ability to easily access information in both model view and the spreadsheets streamlines the process of reviewing the design and making changes.”

Due to the various architectural design choices, cold-formed steel (CFS) framing encloses the concrete form, creating an outer tri-radial elliptical shape. In total, 96 cold-formed steel space frames were designed to handle the changing radius of the elliptical façade while also defining the desired slope of the exterior upper collar. These 50-foot-tall by 12-foot-wide frames were designed in RISA-3D for special wind loading conditions, additional temporary construction platforms, and for assembly on site in a special jig that allowed the frames to be lifted in place assuring that the overall building schedule was met.

S T R U C T U R E solutions 64-SS May 2018

ADVERTORIAL

Architect: Eric Owen Moss Architects, Culver City, CA Structural Engineer: NAST Enterprises Corp., Los Angeles, CA The Pterodactyl is a twostory office building built on top of an existing four-story parking garage in Culver City, CA. This extraordinary structure is formed by the intersection Courtesy of Tom Bonner Photography of nine rectangular boxes, built on top of or adjacent to each other, connected by an interior second-floor bridge and supported by the steel columns extended from the parking structure beneath. The structure accommodates an open floor plan in the main office area including full height windows which provide spectacular views of the nearby cities.

“The simplicity that RISA provides created an environment that allowed the engineer to design something extremely complex.”

The design of the structure was a collaborative effort between the architect and the structural engineer and, as a result, RISA-3D was used extensively during the conceptual design phase. The project’s complexity also required the main structural system (created by using thirty distinct “ring” like steel frames) to be evaluated iteratively.

These exposed elements carry all primary and secondary members and are showcased within the interior design. During this process, the engineer was able to model the stiffness of adjacent elements using springs to evaluate complicated load paths and solve structural problems one at a time.

RISA

Steel/Cold-Formed Steel ProduCtS Guide Bluebeam, Inc.

ENERCALC, Inc.

Qnect LLC

Phone: 866-496-2140 Email: sales@bluebeam.com Web: www.bluebeam.com Product: Bluebeam Revu Description: Tighter budgets. Shorter timelines.

Designing, engineering, bidding, and building are more challenging than ever. So Bluebeam Revu has evolved, to keep you a step ahead. Revu 2018 slides seamlessly into your existing workflows, helping you access and share critical project information more efficiently and complete your projects faster.

Phone: 800-424-2252 Email: info@enercalc.com Web: http://enercalc.com Product: Structural Engineering Library/ ENERCALC SE Cloud Description: Steel design is a breeze with ENERCALC’s Structural Engineering Library (SEL).

Beams, columns, 2D frames, force distribution in bolt groups…SEL handles it all. The clear user interface’s new 3D sketches make it fast and easy to setup, confirm and perform “what-if ” calculations. Member optimization improves your efficiency and saves time!

Phone: 512-814-5611 Email: christian@qnect.com Web: www.qnect.com Product: QuickQnect Description: An intelligent, cloud-based connection app gives fabricators, detailers, and engineers fast and flexible connections and significant cost and schedule savings. In minutes, users can connect most steel buildings without capital cost and with minimal initial training. Two important benefits of Qnect include: Preference Optimization and Bolt Optimization.

IES, Inc.

Simpson Strong-Tie®

Phone: 800-707-0816 Email: info@iesweb.com Web: www.iesweb.com Product: VisualAnalysis Description: Steel frames and trusses are easy to design using VisualAnalysis. Find out why thousands of engineers have trusted IES tools since 1994. Download a free-trial in just a few minutes, and solve your next problem today.

Phone: 800-925-5099 Email: web@strongtie.com Web: www.strongtie.com Product: SHH Steel Header Hangers Description: Developed to support CFS framing box headers as well as large-flange lay-in headers used in curtain-wall construction, the SHH hangers ease installation by reducing drywall buildup. The hanger’s screw count has also been minimized with extensive component assembly testing.

Cast Connex Corporation Phone: 416-806-3521 Email: info@castconnex.com Web: www.castconnex.com Product: Innovative Connection Solutions Description: The leading supplier of cast steel components for use in the design and construction of building and bridge structures. Universal Pin Connectors™, Architectural Tapers™, and Diablo Bolted Splices™ bring off-the-shelf simplicity and reliability to AESS, while custom designed components enable unparalleled opportunity for creativity in design.

Dlubal Software, Inc. Phone: 267-702-2815 Email: info-us@dlubal.com Web: www.dlubal.com Product: RFEM Description: Non-linear FEA software with LRFD and ASD design of hot-rolled steel according to AISC, CSA, and other international standards. Additional features: serviceability deflection checks, tapered and curved beam design, and automatic cross-section optimization. Stress analysis and design of steel surface and shell elements also available, including optimization and serviceability checks.

ADVERTISEMENT–For Advertiser Information, visit www.STRUCTUREmag.org

All archived articles available online www.STRUCTUREmag.org.

MDX Software Phone: 573-446-3221 Email: info@mdxsoftware.com Web: www.mdxsoftware.com Product: MDX Software Description: Used by many top design firms and DOTs to design and rate steel girder bridges for compliance with LRFD, LRFR, LFD, and ASD AASHTO Specifications.

POSTEN Engineering Systems Phone: 510-506-8284 Email: sales@postensoft.com Web: www.postensoft.com Product: TaperSTEEL Description: The design of Tapered Steel Beams and Girders may seem daunting unless you have the right tools. TaperSTEEL provides the Engineer accuracy and time savings and the Architect the freedom to be creative in this truly unique and efficient software.

Product: Simpson Strong-Tie® SBR and DBR Spacer Bracers Description: Load rated and assembly tested, SBR and DBR spacer bracers reduce the installed cost of cold-formed steel stud walls. The SBR and DBR come with pre-punched slots that eliminate the need for bridging clips and enable for a faster layout.

STRUCTUREPOINT Phone: 847-966-4357 Email: info@structurepoint.org Web: www.structurepoint.org Product: Concrete Design Software Suite Description: StructurePoint, formerly the PCA Engineering Software Group, offers concrete design software programs updated to ACI 318-14 for concrete buildings, concrete structures, and concrete tanks. Reinforced concrete structural software includes programs for design of columns, bridge piers, beams, girders, one and two-way slabs, shearwalls, tilt-up walls, mats, foundations, tanks, and slabs-on-grade.

Trimble Phone: 770-426-5105 Email: kristine.plemmons@trimble.com Web: www.tekla.com Product: Tekla Structures Description: Models created with Tekla software carry the accurate, reliable and detailed information needed for successful Building Information Modeling and construction execution. Tekla works with all materials and the most complex structures – you set the limits. Tekla software allows effective information flow: Architects, engineers and contractors can share and coordinate project information.

Demos at www.struware.com Wind, Seismic, Snow, etc. Struware’s Code Search program calculates these and other loadings for all codes based on the IBC or ASCE7 in just minutes (see online video). Also calculates wind loads on rooftop equipment, signs, walls, chimneys, trussed towers, tanks and more. ($250.00).

CMU or Tilt-up Concrete Walls Analyze solid walls for out of plane loading and panel legs next to or between openings by automatically calculating loads to the wall leg from vertical and horizontal loads at the opening. ($75.00 ea) Floor Vibration Program to analyze floors with steel beams and/or steel joist.

Compare up to 4 systems side by side ($75.00).

Listings are provided as a courtesy.

Concrete beam/slab Program to provide bending, shear and/or torsional reinforcing.

Quick and easy to use ($45.00).

STRUCTURE magazine

STRUCTURE® magazine is not responsible for errors.

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May 2018

InSIghtS The Use of Fiber Reinforced Polymer Seismic Retrofit of Masonry Structures with Wood Diaphragms

By John Masek, P.E., S.E., and Briant Jacobs, P.E.

F

iber Reinforced Polymers (FRPs) have been used for seismic retrofit applications in masonry and concrete structures for many years. FRP has also been used for general restoration purposes in wood structures.

Examples include repair and strengthening of wood columns or posts by wrapping with FRP and strengthening of wood beams by either wrapping beams with FRP or by placing FRP of the sides or bottom of wood beams.

When seismically retrofitting masonry shear wall structures with wood roof diaphragms, common seismic retrofit approaches often require partial or total removal of roofing materials, present over the top of plywood roof sheathing, to install diaphragm boundary and other nailing. Thus, it is ideal to construct such retrofit measures when reroofing is required for maintenance reasons.

Sometimes, conventional methods (where roofing material removal is required) are not preferred, either because the roofing materials have many more years of remaining life or partial roof removal is impractical due to warranty concerns and roof construction type, i.e., standing seam roofing materials.

In these cases, consideration of alternate methods to achieve in-plane and out-ofplane load transfer from the structural walls to and from the roof diaphragms should be considered. The use of FRP materials bonded to wood framing and roof sheathing can be evaluated as a possible method of achieving the required connections.

Several different FRP/wood installation configurations were recently reviewed to address many of these challenging conditions. These included in-plane shear transfer for three situations: 2X wood roof framing to plywood sheathing, 2X wood roof framing to oriented strand board (OSB), and plywood or OSB to masonry walls. FRP as a shear transfer material between 2X wood members and plywood (or OSB) sheathing required testing to validate the effectiveness of this approach and to determine allowable design capacities.

On a recent seismic upgrade project in Utah, the design team determined the design loads associated with each configuration where FRP/wood connections were being considered. The team then developed a testing program in cooperation with a major FRP

manufacturing company. The testing program consisted of testing multiple configurations of fiberglass composite sheets bonded onto plywood and 2X wood members. The samples were tested in compression to determine the shear strength of overall wood/ plywood/FRP assembly. The plywood was oriented both parallel and perpendicular to the grain orientation of the 2X wood members. Plywood was also subjected Typical installation of FRP in a wood roof system. to direct pull-off bond testing per ASTM D4541. The ultimate strength design of areas of material bonded to wood, verifica(USD) shear design loads generally ranged tion of lap splice lengths, and inspection of from 500 pounds/linear foot (lbs/lf ) to 1,000 the completeness of bond to wood (i.e., the lbs/lf. The mean ultimate shear strength (at absence of de-lamination or voids beyond failure) from testing was 6,900 lbs/lf, with a prescribed acceptable levels). Other facstandard deviation of 850 lbs/lf. Failure modes tors, such as the required radius of FRP at were consistently wood failure by plywood orthogonal member connections, correlade-lamination. FRP de-lamination did not tion of existing wood types to test specimen occur in any specimen. types, and grain direction of wood are also The design team proceeded to develop final important, but not discussed in this article construction documents utilizing FRP in for brevity. wood-to-wood and wood-to-plywood (or FRP is an effective material for use in seisOSB) connections using data from testing. mic retrofitting of wood roof systems in An installation photograph at a representa- masonry buildings. The procedures used tive location is included in this article. (It made it possible to construct seismic retis noted that the use of various FRP materi- rofit measures without reroofing, thereby als bonded to CMU has been widely used, reducing total project costs by more than and well-documented design methods exist. 50%. Furthermore, given the favorable test Thus, while the CMU to FRP capacity was results, the use of FRP for wood-to-wood included in design calculations, this is not connections need not be limited to situadiscussed in this article.) tions where roof removal is to be avoided, Quality control and surface preparation nor do uses need to be limited to CMU wall requirements are critical when bonding FRP structures. Potential uses of FRP for seismaterials to any substrate. For wood-to- mic strengthening of wood structures could wood FRP applications, surface preparation include roof and floor diaphragm strengthincluded light abrasion of wood and ply- ening in concrete shear wall or brick shear wood with a grinding wheel. In the case of wall structures. The concepts presented are FRP attachment to OSB, only very light also applicable for strengthening of wood abrasion is preferred. Light cleaning of diaphragm connections for other lateral wood surfaces with acetone was then done. loads, such as wind loads. Further testing A bonding agent was applied prior to appli- to develop building code design standards cation of glass fiber sheets and polymers. for FRP uses described in this article would Field testing included direct pull tests, using be appropriate.â&#x2013;Ş the same pull test methods as in laboratory testing. Quality control measures included John Masek is the President of VIE Consultants, an engineering consulting firm based in Roy, Utah. monitoring surface preparation, verification of provided materials before installation, Briant Jacobs is an Engineer with the Weber Basin and field inspections of installed conditions.

Water Conservancy District in Layton, Utah.

These field inspections included verification

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2018 STRUCTURAL ENGINEERING SUMMIT

NCSEA News

News form the National Council of Structural Engineers Associations

October 24–27 | Sheraton Grand | Chicago, IL

Don’t miss this year’s Structural Engineering Summit! NCSEA’s event is the best & biggest it has ever been; educational offerings have been increased for more choices, the Trade Show has expanded by more than 30%, and attendance has grown by over 100% in the last 3 years! Drawing together practicing structural engineers for practical education, a dynamic trade show, and compelling peer-to-peer networking, this event was designed to advance the industry.

Keynote and Plenary Speakers

Host Hotel

In the Opening Keynote, Ron Klemencic, P.E., S.E., Hon. AIA, Chairman and C.E.O. of Magnusson Klemencic Associates, will start off Thursday morning by speaking on the ever-evolving discipline that is engineering.

In his session, “Always Striving for Better,” Klemencic will discuss the advances in material science, construction methods, analytical tools, and design methodologies that continue to provide opportunities for improving on what has been accomplished in the past. During the presentation, he also will review how some of the most impactful innovations in recent years were developed and he will speculate as to what areas are ripe for the next wave of advancements.

Following Klemencic is Stacey Hanke, founder of Stacey Hanke Inc., who has delivered over 500 presentations for business leaders in finance, healthcare, and government.

Her Leadership Plenary presentation, “Influence Redefined…Be the Leader You Were Meant to Be, Monday to Monday®,” will help attendees communicate face-to-face with a clear message, project confidence and credibility, and will provide how-to’s for holding themselves accountable.

Friday’s Luncheon Keynote will answer the question, “is the structural engineering profession positioned to adjust to the impact of these technology-driven ways of the future?”

Ashraf Habibullah is a Structural Engineer and President of Computers and Structures, Inc. In his session, “Empowering The Next Generation of Structural Engineers... to lead, influence, and inspire a changing world!” Habibullah will discuss how the structural engineer’s education and role must change if the profession is to flourish in these rapidly-changing times, and why engineering students need to be exposed to much more than just technology if they are to fully leverage the limitless potential of the profession.

The 2018 Summit will take place at the Sheraton Grand Chicago.

The hotel is located in downtown Chicago just off of the Magnificent Mile (the famous shopping district), and within walking distance to Navy Pier, Millennium Park, the Chicago Riverwalk, and many of Chicago’s famed museums and cultural institutions, making it a great location for exploring the city.

Registration

This year’s registration fees are split into two main categories: Full Conference Plus and Basic Conference Registration.

Each of these categories offer full conference options for First Time Attendees, Young Engineers, and Spouse/Guests. Full Conference Plus includes ALL activities, including the SE River Cruise. If you don’t wish to attend the River Cruise, Basic Conference Registration offers conference pricing without the cruise as well as all other fees, such as regular Full Conference, single day registration, and additional registration for the NCSEA Awards Banquet. All fees are detailed on the NCSEA website; visit the registration tab under the Summit to choose the appropriate fee.

Full Conference Plus Registration Includes: • All Educational Sessions & Resources • Over 25 presentations led by SE & Business Experts • SE River Cruise • A Celebration of Structural Engineering hosted by CSi • Morning & Afternoon Meals • Multiple Networking Opportunities • Refreshment breaks • Trade show access • NCSEA Awards Reception & Banquet • Tour of the Atlas Tube manufacturing mill Basic Full Conference Registration includes all of the above except for the SE River Cruise.

One-of-a-Kind SE River Cruise Hosted by Structural Engineers

This one-of-a-kind event, brought to you by NCSEA and SEAOI and sponsored by Atlas Tube, will offer a river’s-eye view of the structural engineering and architectural marvels along the Chicago River. The cruise will feature special presentations about the architecture surrounding the river delivered by Chicago Engineers & SEAOI Members, our personal docents of the evening.

Food and cocktails will also be available on the fully enclosed, climate-controlled boat.

The SE River Cruise is included in all Full Conference Plus registrations (Full, Young Engineer, and 1st Timer) as well as in the Spouse/Guest Full package Plus.

Visit www.ncsea.com for more information about the 2018 Structural Engineering Summit!

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Entries for the Excellence in Structural Engineering Awards are being accepted!

Each year at the Structural Engineering Summit, NCSEA awards the Excellence in Structural Engineering Awards. This program annually highlights some of the best examples of structural engineering ingenuity throughout the world. Structural engineers and structural engineering firms are encouraged to enter the awards program. Projects are judged on innovative design, engineering achievement, and creativity.

Projects can be entered in one of seven categories: • New Buildings Under $20 Million • New Buildings $20 Million to $100 Million • New Buildings over $100 Million • New Bridges/Transportation Structures • Forensic/Renovation/Retrofit/Rehabilitation Structures up to $20 Million • Forensic/Renovation/Retrofit/Rehabilitation Structures over $20 Million • Other Structures

NCSEA News

2018 Excellence in Structural Engineering Awards

Eligible projects must be substantially complete between January 1, 2015 and June 30, 2018. Entries are due by 11:59 p.m. on Tuesday, July 17, 2018. The process is now entirely online and can be completed by visiting the Awards section of www.ncsea.com.

The NCSEA Grant Program began in 2015 to award SEAs funding for projects that grow and promote their SEA and the structural engineering field in accordance with the NCSEA Mission Statement: NCSEA advances the practice of structural engineering by representing and strengthening its Member Organizations. One of the highlights of the NCSEA Structural Engineering Summit is the announcement of the Grant Award recipients and the projects they will undertake to advance the profession.

The Grant Program is open to any NCSEA Member Organizations or member(s) of a Member Organization.

Requests can be submitted for any program or endeavor that is consistent with, and supportive of, NCSEA’s Mission Statement.

All applications must be approved by the appropriate Member Organization. Visit www.ncsea.com to apply for the 2018 Grant Program and to view past recipients.

Young Member Awards

Each year, NCSEA recognizes its Young Members and Young Member Groups with awards that help fund their experience at the Structural Engineering Summit. The Young Member Scholarship awards new and returning SEA young members funding to attend the NCSEA Summit, which includes a free registration and, for new attendees, a travel stipend. NCSEA members under the age of 36 have the chance to submit applications with written essays or video entries.

The Young Member Group of the Year award recognizes an outstanding SEA Young Member Group that is providing a benefit to their young members, member organization, and communities. Three finalists will receive complimentary registration to send a representative from their YMG to the Summit, where the winning group will be announced.

Visit www.ncsea.com for eligibility, past winners, and the application.

Your Input is Essential to the SE3 Survey

The Structural Engineering Engagement and Equity (SE3) Committee is currently administering a nationwide survey of structural engineering professionals. This survey is designed to provide valuable information about our profession regarding demographics, compensation, satisfaction, and engagement. It will be one of the largest comprehensive nationwide surveys of structural engineering professionals to date and we invite you to contribute to this project by completing the survey.

This project began in 2015 when SEAONC (Structural Engineers Association of Northern California) funded a committee to study engagement and equity in the structural engineering profession. In 2016, this group administered their first national survey of over 2,100 structural engineering professionals. Findings from this study included insight into why engineers leave the profession, the importance of mentorship, and the existence of a nuanced gender pay gap.

In mid-2017, an SE3 Committee was created at the national level through NCSEA with the primary goal of administering a similar nationwide study of structural engineering professionals every two years. This biennial survey will focus on measuring engagement and equity. Its goal is providing data and best practices to help engineers around the country improve the industry and help ensure that every structural engineering professional has a positive experience within our profession.

To participate in the 2018 SE3 survey visit: www.ncsea.com/committees/se3.

NCSEA Webinars

Register at www.ncsea.com.

May 22, 2018 2018 IBC and IEBC Significant Structural Changes Sandra Hyde, P.E. June 5, 2018 Seismic Behavior of Helical Piles in Dense Sands Amy B. Cerato, Ph.D., P.E. Courses award 1.5 hours of continuing education after the completion of a quiz. Diamond Review approved in all 50 States.

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News from the National Council of Structural Engineers Associations

NCSEA Grant Program

SEI Online

Structural Columns

The Newsletter of the Structural Engineering Institute of ASCE

Get Out the Vote

Remember to vote in the ASCE elections for ASCE President-Elect, Region Directors, and for Technical Region Director; the nominees are: • Edward Kavazanjian, Jr., Ph.D., P.E., D.GE, NAE, F.ASCE • David J. Odeh, P.E., S.E., SECB, F.SEI, F.ASCE ASCE members at the grade of associate or above may vote – opens May 1, closes June 1. www.asce.org/elections

You Can Propose Changes to ASCE 7 ASCE 7-22 development has begun. The committee will consider all public proposals received prior to June 30. Submit a proposal using the ASCE 7 Change Proposal Form at https://bit.ly/2GE2HBG where you can also find committee meeting listings.

ASCE Guided Online Courses Topics: Developing Proposals, Crane Lift Plan Preparation, Forensic Engineering, Implementing Geographic Information Systems, Pricing and Bidding: Lump Sum Jobs, Seismic Analysis, and more. www.asce.org/guided-online-courses

Check out the latest SEI News at www.asce.org/SEI including: SEI receives 2018 Pankow Foundation Research Grant to develop a Pre-Standard for Performance-Based Design for Wind

Learning / Networking

ASCE Free E-learning Webinars Career Booster Series sponsored by the ASCE Committee on Younger Members: May 8 Public Speaking for Engineers June 12 Negotiating Skills July 10 Managing Challenging Projects www.asce.org/continuing-education/elearning-webinars

Registration opens May 16 www.etsconference.org.

Proposals Due Session and abstract proposals due June 5 at www.structurescongress.org.

Errata

SEI Standards Supplements and Errata including ASCE 7. See www.asce.org/SEI-Errata.

If you would like to submit errata, contact Jon Esslinger at jesslinger@asce.org.

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SEI Elite Sustaining Organization Members

SEI Sustaining Organization Membership Reach more than 30,000 SEI members year-round with SEI Sustaining Organization Membership Show your support for SEI to advance and serve the structural engineering profession.

Learn more and join today at www.asce.org/SEI-Sustaining-Org-Membership.

Join or Renew SEI/ASCE For innovative solutions and learning, to connect with leaders and colleagues, and enjoy member benefits such as SEI Member Update monthly e-news opportunities and resources – visit www.asce.org/myprofile or call ASCE Customer Service at 800548-ASCE (2723). Follow @ASCE_SEI

Congratulations to the 2018 Structural Award Recipients SEI and ASCE Structural Awards were recognized April 21 at Structures Congress in Ft. Worth:

Moisseiff Award

Moisseiff Award

Biao Hu, A.M.ASCE

Yu-Fie Wu, C.Eng., CPEng, M.ASCE

Gregory G. Deierlein, Ph.D., P.E., NAE, F.ASCE

Raymond C. Reese Raymond C. Reese Research Prize Research Prize

George Winter Award

Trevor D. Hrynyk, Ph.D. A.M.ASCE

Frank M. Vecchio, P.E.

Sigrid Adriaenssens, Ph.D., A.M.ASCE

Nathan M. Newmark Medal

Associate Editor Award (2017)

Alfredo Ang Award (2017)

W. Gene Corley Award

Walter P. Moore, Jr. Award

Dennis L. Tewksbury Award

Billie F. Spencer Jr., Ph.D., P.E., F.ASCE

Fabio Matta, Ph.D., M.ASCE

Bruce R. Ellingwood, Ph.D., P.E., NAE, F.SEI, Dist.M.ASCE

Sarmad (Sam) Albert Rihani, P.E., F.SEI, F.ASCE

Donald R. Scott, P.E., S.E., F.SEI, F.ASCE

David T. Biggs, P.E., S.E., F.SEI, Dist.M.ASCE

SEI President’s Award

SEI Graduate Student Chapter of the Year Award

SEI Chapter of the Year Award

Glenn R. Bell, P.E., S.E., SECB, F.SEI, F.ASCE

SEI Graduate Student Chapter, University of Illinois, Urbana

SEI Colorado Chapter

Learn more and nominate for 2019 awards at www.asce.org/SEI. STRUCTURE magazine

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The Newsletter of the Structural Engineering Institute of ASCE

Shortridge Hardesty Award

Structural Columns

Membership

The Newsletter of the Council of American Structural Engineers

CASE in Point

The Business of Structural Engineering Workshop

June 7 – 8, 2018; Anaheim, CA An Intensive Workshop for Structural Engineering Firm Leaders and Project Managers Real-World Skills… Strategic Insights…

Best Practices for Success Managing your structural engineering business for success requires technical know-how coupled with a broad awareness of today’s best business practices. Firm managers must know the rules of finance and how they work in the real world, and the ins and outs of managing people, risk, and resources, including: • Understanding Duty-to-Defend and How to Protect Your Firm • Avoiding Getting Burned by Electronic Communications • Driving Financial Performance Through Metrics • Navigating Your Way Through High-Risk Projects • Transitioning Project Managers to Firm Leaders Contemporary Best Practices and Critical Operational Management Methods This workshop highlights strategies for a wide array of critical business topics that will keep your business thriving, despite a churning business environment.

Attendees will learn specific skills and techniques to help them manage change and build success in finance, leadership development, contracts, and risk. This workshop is presented by the Council of American Structural Engineers (CASE), the leading provider of business practice and risk management information for structural engineering firms. Structural engineering firms are not simply run on technical know-how – you cannot be successful without understanding the basics of the business world. The Business of Structural Engineering Workshop will share challenges facing today’s structural engineering firms and how to address them.

What Will Attendees Learn?

Attendees will leave the event with best practices to assist your firm in: • Reducing claims • Increasing profitability • Improving quality • Enhancing management practices

Workshop Schedule Thursday, June 7 5:30 pm Workshop Dinner and Presentation Enhance Project Performance through Team Culture: California Pacific Medical Center (CPMC), Van Ness IPD Project Speakers: Stacy Bartoletti, President and CEO, and Jay Love, Senior Principal – Degenkolb Engineers

9:15 am – 10:30 am Did I Say That!? Electronic Communication, Retention, and Back-up in the Engineering Practice Karen Erger, Lockton Eric Singer, Ice Miller, LLP 10:45 am – 12 Noon Key Business Metrics Matt Fultz, Matheson Financial Advisors, Inc. 12:00 Noon – 1:30 pm Lunch

Friday, June 8 6:45 am – 7:30 am Breakfast

1:30 – 2:45 pm Projects with the Largest Losses and Claim Frequency Tim Corbett, SmartRisk Brian Stewart, Collins, Collins, Muir + Stewart

7:30 am – 7:45 am Welcome Corey Matsuoka, SSFM International 7:45 am – 9:00 am California Duty to Defend Reform (SB 496) Brett Stewart, XL Catlin Design Professional Michael Olson, Dealey, Renton & Associates

3:00 pm – 4:15 pm Transitioning Project Managers to Firm Leaders Howard Birnberg, Birnberg & Associates

Get Full Program and Registration Details at http://bit.do/acec-case2018.

Follow ACEC Coalitions on Twitter – @ACECCoalitions.

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Title Sponsor: CSI Lanyard Sponsor: MATHESON FINANCIAL ADVISORS Workshop Partner: ACEC/CALIFORNIA NCSEA SEI Gold Patrons: ARW ENGINEERS DEGENKOLB ENGINEERS Silver Patrons: BKBM ENGINEERS LARSON ENGINEERS SSFM INTERNATIONAL Bronze Patron: MORRISSEY GOODALE, LLC

Seeking Workshop Patron Sponsors Be a patron sponsor and get additional registration slots!

Interested in taking advantage of this special sponsorship, contact Heather Talbert for more information: htalbert@acec.org or 202-682-4377.

Patron Sponsor (Gold – $2,000; Silver – $1,500, Bronze – $1,000) Sponsor the “Business of Structural Engineering” as a Patron of CASE • VIP Seating at Dinner/Lunch • Listed on all materials and promotions • Listed on all signage • Gold – Three (3) Registrations • Silver – Two (2) Registrations • Bronze – One (1) Registration

CASE in Point

Thank You to Our Workshop Sponsors

CASE Risk Management Tools Available

Tool 1-1: Create a Culture for Managing Risks and Reducing Claims The most comprehensive CASE tool that provides sample templates and presentations that aid in creating a culture of risk management throughout the firm.

Tool 1-2: Developing a Culture of Quality This tool was developed to identify ways to drive quality into a firm’s culture. It is recognized that every firm will develop its own approach to developing a culture of quality, but following these 10 key areas offers a substantial starting point. The tool includes

a white paper and customizable PowerPoint presentation to facilitate overall discussion.

Tool 1-3: Sample Policy Guide An employee handbook is a document that contains a company’s operating procedure, and is used to establish important policies and to protect the rights of the employers and employees. Done well, an employee handbook helps maintain a professional environment by documenting the expectations of the entire workforce.

CASE Tool 1-3: Sample Policy Guide is an outline of what a typical employee handbook could contain. As every employee handbook should be personalized for a Firm’s culture and location, policies are not written out. Instead, for each policy, a short description and items to include or be aware of are described. For Companies who already have an employee handbook, use Tool 1-3 as a checklist to make sure all important policies are included or that policies are written appropriately. For Companies who do not have an employee handbook, Tool 1-3 will be a great starting point to write one.

You can purchase these and the other Risk Management Tools at www.acec.org/bookstore.

Applying Expertise as an Engineering Expert Witness Thursday, May 31, 2018, and Friday, June 1, 2018; San Francisco, CA Engineers are often asked to serve as expert witnesses in legal proceedings – but only the prepared and prudent engineer should take on these potentially lucrative assignments. If asked, would you be ready to say yes? Developed exclusively for engineers, architects, and surveyors, this unique course will show you how to prepare for and successfully provide expert testimony for discovery, depositions, the witness stand, and related legal proceedings.

Applying Expertise as an Engineering Expert Witness is a focused and engaging 1½-day course that will run you through each step of the qualifications, ramifications, and expectations of serving as an expert witness, including: STRUCTURE magazine

• Proper courtroom demeanor • Maintaining credibility • Differences between a fact witness and an expert witness • Deposition behavior • Permissible out-of-court statements • Ethics • Pre-courtroom testimony preparation • Using visual aids … and more!

Get Full Program and Registration Details at http://bit.do/acec-expertwitness2018.

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CASE is a part of the American Council of Engineering Companies

Foundation 1: Culture – Create a Culture of Managing Risks & Preventing Claims • Structural engineering is a high-risk profession • All firms can have professional liability claims • Claims cost money, time, reputation, clients, and staff • Firms must commit to managing risks • Commitment must include management, staff, and clients.

All individuals must make a commitment • Quality must take high precedence • The legal environment is always changing

Spotlight

award winners and outstanding projects

Riverfront Revival

By Paul Evans Silman was an Award Winner for its Empire Stores project in the 2017 Annual Excellence in Structural Engineering Awards Program in the Category – Forensic/Renovation/ Retrofit/Rehabilitation Structures over $20M.

T

he Empire Stores complex is a series of seven interconnected warehouses initially built between 1869 and 1885 on the Brooklyn waterfront just north of the Brooklyn Bridge.

The warehouses are constructed of heavy timber columns, girders, and joists with brick exterior bearing walls and large schist party walls. At the time of construction, the buildings varied from four to five stories in height. The structures were originally used to store shipping goods arriving in Brooklyn from around the world. However, in the early twentieth century, the Empire Stores were purchased by Arbuckle Brothers, the company that first developed the process for selling coffee in sealed packages, and were used for the storage of green coffee beans. After WWII, as shipping and industry left the area, the warehouses fell into disuse and disrepair. Though added to the National Register of Historic Places in 1974, the buildings sat almost empty until work began for this project in 2013.

The goal of this adaptive reuse project was to reincorporate the long-vacant buildings into the neighborhood, to re-engage the waterfront, and to reconnect the site’s breathtaking views of the Manhattan skyline with the public.

This was to be done through an extensive rehabilitation of the existing structure, the insertion of the slice – a void created through the structure – and a 1- to 2-story vertical addition. The site will house restaurants, retail spaces, offices, and a new public green roof.

This work also included bringing electricity to the building for the first time in its history.

The process began with an exhaustive existing conditions survey of the 330,000 square feet making up the seven historic buildings.

The existing bearing walls and heavy timber columns and floor framing were documented, and a repair plan was created. For the walls, this included removing and replacing damaged areas of brick, stitching and repairing cracks, and extensive repointing. The creation of the slice and the carving out of the rear of one warehouse to house mechanical equipment required extensive removal of heavy timber framing, which was then reused to replace damaged timber throughout the structure to limit the impact of timber repairs on the historic fabric of the buildings. By a stroke of luck, the removed timber correlated almost directly with the timber needing to be repaired, and no new heavy timber was required. The existing seven warehouses, which were all separated by solid party walls, were also joined through the creation of 120+ floor-to-floor openings, allowing for the necessary circulation through the buildings.

With a plan for the existing superstructure established, the focus turned to the foundations. The structure is on an area reclaimed from the East River, which consists of a top layer of uncontrolled fill and organic clays and peat below. The bearing walls were originally supported on timber piles, and the interior timber columns – built in a tight, rectilinear 10-footby-15-foot grid – were founded on isolated stone footings. Most of the timber piles had completely rotted away, requiring roughly 2,100 linear feet of bearing walls to be supported on new foundations. A 24-inch mat slab system was designed to re-support the bearing walls and columns. The mat slab was propped up on helical piles to help control future settlement of the clay substrates below. A separate mat slab was poured in each building, and more than 300 existing timber columns were systematically shored and

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re-supported on the new mats. Hundreds of 16-inch-diameter cores were cut through the base of each of the 2.5-foot-thick schist party walls, and steel needle beams were installed and grouted solid to allow for the transfer of all the vertical loads in the base of the walls to the new mat foundations without the need for underpinning.

With new foundations in place and a stabilized superstructure, the team could next address the vertical addition. For it to be functional, a modern column layout – approximately 20 feet by 30 feet – was necessary. A composite steel structure with concrete on metal deck was designed to suit this layout. This required transitioning from the larger column bay spacing down to the existing 10-foot-by-15foot timber column and bearing wall layout of the existing structure. The new column locations were laid out to avoid overstressing individual areas of existing framing below, with new columns landing on the large existing bearing walls whenever possible. Where this was not feasible, new columns were placed on steel transfer beams to spread the addition’s loads to at least two existing timber columns below.

The strategic layout of the addition’s framing, along with the fact that the existing structure was originally designed for live loads of 250 psf or more, allowed for the new overbuild to be placed on top of the existing structural elements without the need for timber reinforcing or new steel columns in the historic spaces.

Through creative design solutions and extensive rehabilitation, Empire Stores was transformed from an abandoned piece of local history to a vibrant, inviting community space, revitalizing the neighborhood and attracting people from around the world to the Brooklyn waterfront.▪ Paul Evans is a Senior Engineer with Silman.

He can be reached at evans@silman.com.

Structural Forum Licensure of Structural Engineers Thoughts from an E.I.T.

By Edward Major II, E.I.T.

I

believe engineering is one of the most important professions in a civilized society.

Similar to the way the public relies on medical professionals to keep us healthy and to prevent injury and illness, the public relies on the professional engineer to design safe structures and equipment. Engineers improve the lives of people across the globe. We wake up to an alarm clock (electrical engineer). We take a car, bus, train, or bike (mechanical engineer) on highways, over bridges, and through tunnels (civil engineer). We spend most of our time in houses, office buildings, or warehouses (structural engineer). Society relies on engineers to design, check, and recheck many elements, all of which are used by the public, to ensure their safety and continued serviceability.

When I buy a sweater, I am not worried whether that sweater was created by a “professional knitter.” I do not have this worry because I can easily trust that this item will pose no harm.

However, most who utilize the services of an engineer do not know if that engineer’s solution to their problem will harm them or their peers. Professional licensure bridges this gap by providing proof that an individual has met the required professional standards to practice.

My goal is to obtain my Professional Engineer (P.E.) and Structural Engineer (S.E.) licenses as evidence to the public that I can be trusted with their well-being.

Examination for professional engineering licensure is not a new idea. Most states began to require testing of new engineering graduates for an “Engineer-in-Training” license and further testing for the professional license beginning in the 1950s. It was not until the 1990s that every state (including the District of Columbia) required both the fundamentals exam (Engineer-in-Training) and the professional exam (P.E.) as a means to establish a minimum level of competence and to evaluate a candidate’s knowledge of basic engineering concepts and principles.

Since the 1950s, engineering has become vastly more complex. While the underlying principles of engineering have stayed the same, the processes have changed as the structures we design become taller, larger, and

more complicated. Because of this, I believe the engineering profession should examine the possibility of recognizing an additional credential for the structural engineers.

The P.E. exam is meant to be the minimum benchmark of competence for an engineer.

The key word here is minimum. Thirty years ago, a person taking the P.E. exam chose and solved eight questions from a variety of engineering topics.

Today, the P.E. Civil-Structural exam consists of a 4-hour morning session (general civil) and a 4-hour afternoon session (one of five specialist areas). The structural portion of this exam is a mere 40 questions. While that may seem to be an appropriate number, a closer look at the NCEES exam specifications reveals there are four questions on loads (such as wind, snow, and seismic loading) and their applications influencing structures. Does solving four questions covering these topics seem adequate to assess a structural engineer’s competence? I do not think it does. By contrast, the NCEES S.E. exam consists of 8 hours of lateral forces (wind/ seismic) and 8 hours of gravity forces (dead, live, and snow loads). This is why, as noted previously, the P.E. exam should be considered a minimum level of competency and structural engineers should strive to pass the S.E. exam, a higher level of competency.

Passing the S.E. exam may not be necessary for some professional engineers already providing structural engineering services.

Years of experience can yield a vast increase in one’s abilities to understand and design complex structures. Recognizing the experience of an engineer gained after he or she has become licensed is important, and should be considered when qualifications are assessed.

Although some states agree with this premise, other states have refused to do so.

In 2015, the Florida Structural Engineers Association proposed legislation that would require all threshold buildings (defined in Florida as any building greater than 3 stories or 50 feet in height, with an area greater than 5,000 square feet or an occupancy load greater than 500 persons) to be sealed by a licensed Structural Engineer. All other structures can

be sealed by a P.E. practicing in their area of competence. The bill passed the House on March 27, 2015 (107 YAY to 2 NAY) and the Senate (38 YAY to 2 NAY) on April 23, 2015. However, in June of that year, Governor Rick Scott vetoed the bill. He did so because he felt that the transition clause, which allowed some structural engineers to forgo the 16-hour exam, was unfair and that everyone should be required to pass the S.E. exam. This kind of logic is unacceptable to the public and the profession.

While Florida’s attempt fell short, other states have been more successful. There are currently two states that have a full practice restriction on structural engineering. Illinois and Hawaii only allow a structural engineer who has an S.E. license to seal structural drawings for any type of structure. Other states such as California, Nevada, Utah, Oregon, Washington, Oklahoma, and Alaska have partial practice restrictions where certain types of structures must be sealed by a licensed Structural Engineer. These states passed licensure for structural engineers with legislation that acknowledged the accomplishments of those who passed the NCEES 16-hour S.E. exam, but also provided a transition clause for those practicing structural engineering who, as a result of their years of practice, were considered competent and equal.

For the protection of the public, structural engineers should acknowledge the advancement of our profession and support licensure for structural engineers who have passed the NCEES 16-hour S.E. exam or demonstrated their competence through years of practice.

Additionally, we need to hold new engineers in training (EIT) aspiring to become structural engineers to a higher standard by requiring the more useful measure of competence that is the S.E. exam.▪ Edward Major II (emajor@wbcm.com) is a structural engineer in Pittsburgh, PA, for Whitney, Bailey, Cox & Magnani. He is active within several professional organizations including the NCSEA Structural Licensure Committee and the Pittsburgh Section of ASCE.

Structural Forum is intended to stimulate thoughtful dialogue and debate among structural engineers and other participants in the design and construction process. Any opinions expressed in Structural Forum are those of the author(s) and do not necessarily reflect the views of NCSEA, CASE, SEI, the Publisher, or the STRUCTURE® magazine Editorial Board.

STRUCTURE magazine

75

May 2018

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