InSights

ASTM A1085

An Update to a Classic Material Specification

By Kim Olson, P.E.

ASTM A500 has been the preferred material specification in the United States for cold formed, welded carbon steel hollow structural sections (HSS) since the late 1970s. In April of 2013, a new material specification, ASTM A1085, was released for steel tubes used in structural applications. The development of A1085 took approximately six years and was led by the American Institute of Steel Construction’s (AISC’s) HSS Marketing Committee. The goal of the Committee, which also included HSS producers, was to improve the efficiency and performance of the HSS members in three main areas: material, seismic design and bridge design. Traditionally, ASTM A500 allowed for a wall thickness tolerance of -10% of the value specified. Hence, manufacturers have produced tubes with a design thickness of up to 10% less than the nominal thickness required by the standard. This reduction in material led to recommendations made jointly between AISC and the Steel Tube Institute (STI), leading to provisions (AISC 2010 Specification for Structural Steel Buildings ANSI/AISC 36010, Section B4.2) requiring a reduction in the nominal thickness of all HSS members by 7% for all HSS section calculations. In comparison, A1085 tightens the wall thickness tolerance to -5% and adds a new mass tolerance of -3.5%. These tighter restrictions better align HSS tolerances with other structural members and eliminate the need for the 0.93 factor in calculations. Obviously, these improvements result in more efficient designs when utilizing HSS. Designers are aware A500 includes four distinct grades of steel for different HSS section shapes, each having different yield and tensile strengths. A1085 greatly simplifies these values for the designer. The specification has one grade and one yield strength (of 50 ksi) for all HSS shapes. This value represents an increase over A500 Grade B, offering another potential savings. Bending a flat plate of steel into a square or rectangle shape requires careful attention to the radius of the corners. Too tight of a bend could lead to cracking, which often is not visible until a weld is made along the corner of the member and is subjected to extreme heat. A500 lists a maximum corner radius but does not limit the minimum radius bend, whereas A1085 specifies both a minimum and maximum for the reasons listed above. For material that is less than 0.4-inch thick, the corner radius is permitted to be between 1.6t and 3.0t. For material greater than 0.4inch thick, the lower bound of the corner radius is 1.8t. Most domestic manufacturers produce tubes with a corner radius of 2t so there will be little difference in the workable flat face of a tube. A common application of HSS members is in a braced frame to resist seismic load. HSS sections are often utilized as the bracing element due to their efficiency in carrying both tension and compression loads. This efficiency has come at a price when designing a building with a resistance factor (R) of greater than 3. The seismic provisions of AISC 360 require an engineer to focus on the actual capacity of a member in order to control the failure mechanism of the lateral force resisting system. To realize the actual capacity of a steel brace, a designer must multiply the specified yield strength by an overstrength factor (Ry) to account for inherent overstrength in steel members. Ry for A500 is 1.4, while Ry for A992 is 1.1. Clearly, the larger Ry results in a nearly 30% increase in force the designer must account for. The high Ry for A500 is due to the high variability in acceptable yield strength of tubes. A1085 specifies an upper bound on the yield strength of 70 ksi. In time, this upper bound limit will logically lead to better predictability of the material strength, a lower Ry factor, and more economical seismic designs utilizing HSS members. Historically, HSS members have not been used frequently in pedestrian and vehicular bridges, but the demand to utilize these architecturally pleasing shapes in transportation structures has increased. According to the American Association of State Highway and Transportation Officials (AASHTO), sufficient fracture toughness is a requirement for primary bridge members. Accordingly, A1085 includes a Charpy V-notch test requirement of 25 ft-lb at 40°F. This corresponds to an AASHTO Temperature Zone 2, which is applicable throughout the majority of the United States. If more stringent requirements must be met, A1085 carries a supplement that may be specified. Hence, A1085 allows for the usage of HSS shapes in the transportation field by meeting the requirements of AASHTO. A1085 is already an option for designers when selecting a material to use for design in software packages. STI has been in contact with most major design software companies to better educate them on the intricacies and advantages of new specification. RISA, SCIA Engineer, RAM Structural System and RAM Elements all will include the new material and section properties in their updates to be released in the near future, with other software packages to follow. AISC has surveyed domestic manufacturers on A1085 production and the results of that survey are available on the AISC website (www.aisc.org/hss) along with section properties and column load tables for A1085. Further, the new section properties are also available on STI’s website (www.steeltubeinstitute.org/hss/ tech-brochures), and any questions on A1085 may be submitted in the Contact section to be answered by STI’s Technical Consultants.▪ Kim Olson, P.E., is a structural engineer at FORSE Consulting and serves as a technical advisor to the HSS Committee of the Steel Tube Institute. Kim may be reached at kim@forseconsulting.com.

Bentley Systems, Inc.

Phone: 610-458-1491 Email: francisco.diego@bentley.com Web: www.bentley.com/structural Product: RAM Connection Description: e software includes base plates for almost any kind of column support. Choose between uniaxial or biaxial analysis, design the base plate per AISC 360-05 (additional seismic check per AISC 341-05 included), design the anchor bolts per ACI 318 Appendix D in seconds.

Cintec Reinforcement Systems

Phone: 800-363-6066 Email: solutions@cintec.com Web: www.cintec.com Product: Cintec Reiforcement Anchors Description: e patented Cintec anchoring system is straightforward: injecting a proprietary cementitious uid grout into an anchor surrounded by a fabric sock, which has already been placed in an oversized drilled hole. e system’s ingenuity lies in its versatility. Cintec designers can customize it to any speci cation.

Devco Software, Inc.

Phone: 541-426-5713 Email: rob@devcosoftware.com Web: www.devcosoftware.com Product: LGBEAMER v8 Description: Analyze and design cold-formed cee, channel and zee sections. Uniform, concentrated, partial span and axial loads. Single and multi-member designs. 2007 NASPEC (2009 IBC) compliant. Pro-Tools include shearwalls, framed openings, X-braces, joists and rafters.

Grip-Tite Mfg. Co., LLC

Phone: 515-462-1313 Email: nfarkas@griptite.com Web: www.griptite.com Product: Anchors and Piles Description: Grip-Tite provides a complete line of anchors and piles for general construction and retro t applications. is includes Push Piers, Helical Piles and Anchors and Wall Anchor retention systems. Grip-Tite has been continually manufacturing highquality anchoring products since 1921.

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Phone: 800-423-9140 Email: pschmidt@halfenusa.com Web: www.halfenusa.com Product: Anchor Channels Description: Halfen is a global leader in design and manufacturing of anchor systems for concrete. Hot rolled anchor channels for edge or top of slab transfer high loads while also providing eld adjustability. Custom anchors are available for special corners and thin slab conditions.

Heckmann Building Products, Inc.

Phone: 800-621-4140 Email: david@heckmannanchors.com Web: www.heckmannanchors.com Product: Pos-I-Tie® ermalClip™ Description: is new break-through in masonry construction adds thermal-break technology to all of the advantages of the Original Pos-I-Tie Veneer Anchoring System! e ermalClip decreases thermal transfer and has over 100 times less conductivity than metals such as steel. e snap-on design provides for easy installation.

Hilti, Inc.

Phone: 800-879-8000 Email: us-sales@hilti.com Web: www.us.hilti.com Product: Hilti HIT-HY 200 Adhesive Anchor System Description: e industry’s most revolutionary system to date. Inadequately cleaning holes during installation can reduce the performance of conventional adhesive anchor systems. Hilti Safe Set™ Technology eliminates this almost entirely, and improves reliability and productivity because no manual hole cleaning is required to obtain optimum performance.

Hubbell Power Systems, Inc. – CHANCE

Phone: 855-477-2121 Email: civilconstruction@hubbell.com Web: www.abchance.com Product: Helical Anchors Description: A helical anchor/pile is a segmented deep foundation system with helical bearing plates welded to a central steel shaft. Load is transferred from the shaft to the soil through these bearing plates.

IES, Inc.

Phone: 800-707-0816 Email: sales@iesweb.com Web: www.iesweb.com Product: IES VisualAnalysis Description: VisualAnalysis o ers ACI Anchor Design checks with the base plate design feature included in VAConnect. Use VisualAnalysis for a wide variety of analysis and design projects. It is simple, productive and versatile.

Kelken Construction Systems

Phone: 732-416-6730 Email: dick@kelken.com Web: www.kelken.com Product: Keligrout Anchor Systems Description: Structural high strength polyester anchoring system. Powers Fasteners

Phone: 985-807-6666 Email: jack.zenor@sbdinc.com Web: www.powers.com Product: Anchoring Systems Description: ICC Listed/IBC Compliant Anchoring Systems: Powers-Stud+ SD1/SD2 carbon steel wedge anchors; Powers-Stud+ SD4/SD6 304/316 stainless wedge anchors; Powers-Stud SD5 galvanized carbon steel wedge anchors; Pure 110+ adhesive anchoring (meets high temperature performance requirements in IBC 2012).

Simpson Strong-Tie

Phone: 925-560-9000 Email: web@strongtie.com Web: www.strongtie.com Product: Anchor Products Description: Wide range of code-listed and general purpose anchoring, fastening, and repair products for concrete and masonry applications. Design software, adhesives, mechanical anchors, gas and powderactuated tools and fasteners, carbide drill bits, and repair, protection and strengthening products o er innovative solutions for infrastructure, commercial, industrial and residential construction.

Standards Design Group, Inc.

Phone: 800-366-5585 Email: info@standardsdesign.com Web: www.standardsdesign.com Product: Window Glass Design 5 Description: WGD5 performs all required calculations to design window glass according to ASTM E 1300-09. WGD5 also performs window glass design using ASTM E 1300 02/03/04, ASTM E 1300-98/00 and ASTM E 1300-94. GANA endorses WGD5 as best tool available in designing window glass to resist wind and long-term loadings.

Strand7 Pty Ltd

Phone: 252-504-2282 Email: anne@beaufort-analysis.com Web: www.strand7.com Product: Strand7 Description: An advanced FEA system used worldwide by engineers for a wide range of structural analysis applications. It comprises preprocessing, a complete set of solvers and post processing. It includes a range of material models suitable for the analysis of soil allowing for simulations of the complete soil/structure system.

Timberlinx

Phone: 877-900-3111 Email: timberlinx@rogers.com Web: www.timberlinx.com Product: Timberlinx Description: A connection tube, inserted equally in both members of the joint and linked by two expanding cross pins. Wood/wood, wood/concrete, wood/steel connectors.

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FOUNDATIONS

Foundation Sector Grounded in Optimism for New Year

By Larry Kahaner

2014 is shaping up to be a strong year, according to those working in the foundations sector. “We probably have more backlog going into a winter of a new year than I can remember,” says Lyle Simonton, Director of Business Development at Subsurface Constructors, Inc. (www.subsurfaceconstructors.com), St. Louis, Missouri. “We’re not seeing that winter slowdown that we’ve sometimes seen in the past. Rather than have a seasonal lull, we have a lot of work carrying on into the fi rst months of the year.” Jim Hussin, Director at Hayward Baker, Inc. (www.haywardbaker.com) in Tampa, Florida agrees. “Th ere has been a steady increase in work in the past few years to where, when combined with our acquisitions, we are now back to record sales volumes.” What appears to be driving the industry are a growing economy, new off erings that are attracting business, and a general optimism among those companies who have survived the lean years of the building slowdown. One sign of improvement is companies that recently relied heavily on government work are now seeing increases in private work. Says Kord Wissmann, President of Davidsonville, North Carolina-based Geopier Foundation Company (www.geopier.com), “Like the rest of the construction industry, we have seen a rebound in residential (multi-family) developments along with the light commercial and retail projects that follow.” He also credits increasing worldwide awareness of seismic risks for interest in companies like Geopier that engage in soil mitigation. Th e company specializes in providing a wide variety of cost-eff ective ground improvement solutions to support load ranges on any project, Wissmann says. “Recent innovations including the Geopier Armorpact system, provide structural engineers with the tools to support higher loads with increased allowable bearing pressures in very soft cohesive soils. Th e Geopier Densipact system aff ords allowable bearing pressures of up to 14,000 psf in granular soils. All of these systems are geared to save time and money for foundation construction.”

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Wissmann adds: “Historically, the industry has focused on liquefaction mitigation using soil densification techniques. This remains the case on many projects. There is also a growing trend towards the use of more cost-effective approaches by reducing liquefaction triggering while simultaneously addressing dynamic settlement – particularly differential settlement. Geopier uses many of its systems, for example, its Impact pier technology, to reduce liquefaction-induced settlements while providing cost-effective foundation support.” (See ad on page 48.) Hayward Baker’s Hussin notes that soil mixing is a relatively new product offering. The process improves weak soils by mechanically mixing them with a cementitious binder, and it continues to gain popularity. “The binder can be added as a slurry for dryer soft soils or as a dry powder to very wet soft soils. To construct columns, a powerful drill advances drill steel with radial mixing paddles located near the bottom of the drill string. The binder is pumped through the drill steel to the tool as it advances, and additional soil mixing is achieved as the tool is withdrawn. To perform mass soil mixing, or mass stabilization, a horizontal axis rotary mixing tool is located at the end of a track hoe arm. The technique has been used to strengthen soft soils at sites of planned buildings, storage tanks and embankments,” he says. One impetus for soil mitigation, according to Hussin, is an increase of soft soil sites, particularly port facilities. Recently, the company acquired Geo-Foundations, a full-service geotechnical construction firm operating out of Toronto, Ontario. “This demonstrates Hayward Baker’s commitment to the Canadian market, especially when combined with our parent company Keller’s recent acquisition of the assets of North American Energy Partners’ piling division, known as North American Caisson (NAC). The company has been renamed Keller Foundations Ltd.,” says Hussin, “and it operates throughout Canada.” Simonton says that Subsurface continues to build on its capacity to perform ground improvement work all over the country. “We have created some new equipment to support that endeavor, and it’s led to work even further away from our traditional Midwestern base,” he says. “We’re doing a lot of work in the Northeast, the New England area… we’ve just seen a lot of development, commercial and otherwise, all over the U.S. but in the Northeast in particular. I think a lot of people assume that we’re a smaller, Midwestern company, that there’s no way we could cost-effectively travel to the Northeast and be competitive. And yet, we’ve done about four or five Boston and New England-area projects in the last year or two.” At CTS Cement Mfg. Corp. (www.ctscement.com) in Cypress, California, Marketing Director Janet Ong Zimmerman also says that business is improving. “Things are better than last year and slowly going in the right direction… We are seeing a gradual, yet steady, recovery in the commercial, industrial and non-residential markets.” The company manufactures Rapid Set fast-setting hydraulic cement and Type K shrinkage compensating cement. “Rapid Set exceeds 3000 psi in one hour, which means you can make structural repairs and rehabilitation, and return the concrete to full use in just one hour,” Zimmerman says. She would like SEs to know about Rapid Set Flooring Products that “offer a complete way to repair, resurface and renew interior and exterior floors.” She adds: “Products include TRU Self Leveling for polished overlays and toppings, LevelFlor for self-leveling underlayment, acrylic and epoxy primers, Skim Coat for patching and skim coating, and repair mortars.” In addition, the company is touting Rapid Set Corrosion Inhibitor which continued on page 49

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provides triple-protection against corrosion. “It increases corrosion resis- aggregates that is used at any thickness from 1½ to 24 inches. tance when used in areas susceptible to corrosion and chloride. It repels It delivers 20-30 minutes of working time. water, thereby preventing an unsightly appearance to concrete. It reduces Owens notes that he’s seeing an interest in turning plain, grey conchloride permeability, thereby increasing the life expectancy of metals, crete into attractive surfaces. “With this growing interest in designer steel and rebar,” Zimmerman says. (See ad on page 3.) concrete, we’ve introduced a new suite of advanced formula concrete John Somers, Vice President of Sales/General Manager at Polyguard décor products including stains, sealers, coatings and cleaners. Products (www.polyguardproducts.com), Architectural Division On the testing side of the foundations sector, Senior Consulting in Ennis, Texas announced that his company is celebrating its 60th Engineer, Marketing Director Gina Beim of Pile Dynamics, Inc. anniversary. “Our Architectural Division provides high quality water- (www.pile.com) of Cleveland, Ohio, says that her company has witproofing membranes for both pre and post pour concrete applications nessed an ‘explosion’ of popularity of the Thermal Integrity Profile (TIP). as well as drainage boards, thru wall flashings and the best sealants “The interest in evaluating the shape of drilled foundations using TIP and transition products in the industry. In addition we manufacture with either data collection method – thermal probes or thermal wire a complete line of fluid applied air barrier and waterproofings.” cables – is increasing, and the industry recognizes that. The TIP received He says that for some SEs, Polyguard may be a new name but their two innovation awards in 2013 – one from the Deep Foundations products, such as Underseal and 650, are likely to be familiar. “In institute and the prestigious NOVA Award for Innovation from CURT/ 2013, we launched a new balcony product called Balconyguard. This CIF (Construction Innovation Forum). In 2013 some testers branched is a membrane product and system specifically designed for balcony out to try the thermal profiling on jet grouting columns, soil nails and applications. We also introduced a series of pre-fabricated boot prod- micropiles. It’s exciting to see these new applications tried out, and PDI ucts for waterproofing around columns and penetrations. They save thinks most of them will open new markets for the TIP.” time and are easy to install,” Somers says. The company also increased the number of options available for its “The boots were a result of customer requests. Job-site fabricated Pile Integrity Tester. “That’s PDI’s instrument for pulse echo testing boots are time consuming and cumbersome, particularly in harsh job of concrete foundations. The PIT, as it’s known, now comes in two site and poor weather conditions. Having the boots prefabricated in sizes (some people favor a compact size, others prefer a larger screen advance saves time, and results in a high quality job in the end,” says to visualize results), with either wireless or traditional (cabled) sensors, Somers. (See ad on page 50.) and with either one or two channels of data acquisition.” Another company celebrating longevity is The QUIKRETE PDI hasn’t stopped there, Beim says. “We have developed another device, Companies (www.quikrete.com) of Alpharetta, Georgia, says Frank an instrument for independent inspectors of ACIP / CFA piling jobs. It Owens, Vice President Marketing. “We were founded nearly 75 years streamlines and standardizes the entire process of recording the installation, ago, and we manufacture more than 200 professional-grade products something that inspectors still tend to do with pencil and paper. PDI will including mortar mixes, cements, concrete repair products, stucco, start marketing it to inspectors soon,” she says. Speaking about 2014, Beim waterproofing, tile setting, blacktop products, floor underlayments, predicts that the U.S. market will remain steady. “Outside the U.S., some sand and aggregates from more than 100 facilities in the U.S., Canada, countries are seeing increased interest in foundation quality control, either Puerto Rico and South America.” just as a natural evolution of construction practices or because new codes Owens says that the company has a state-of-the-art technical center have been enacted that require or incentivize deep foundation testing. where research and development is constantly driving product enhance- One example is Sweden, which now requires pile driving ments. “Our FastSet line, which features five products designed for monitoring in virtually all construction sites. Brazil requires rapid strength gain while providing contractors with adequate time a significant amount of pile load testing, too. PDI’s reprefor mixing, pouring and finishing projects, is a great example of sentatives are, therefore, cautiously optimistic,” says Beim.▪ QUIKRETE product innovation.” He also wants SEs to know about three FastSet products that are designed specifi- Thermal Integrity Profiler cally with engineering job requirements in mind. The Heat Is On. • • QUIKRETE FastSet Repair Mortar uses a special low-sag formula to make vertical and overhead structural repairs to any concrete, masonry or stucco surface. It delivers 20-30 minutes of working time and allows sculpting of the material during placement. QUIKRETE FastSet Non-Shrink Grout is designed for structural concrete repairs from ¼ to 24 inches deep, and can be mixed to a plastic, flowable or fluid consistency. It delivers 30 minutes Shape, quality, cage alignment and concrete cover of drilled shafts. Shape and quality of jet grouting columns. Data acquisition with Probes or Thermal Wire® cables. TIP: test fast and soon after casting, so construction can move on. Winner of the DFI 2013 C. William Bermingham Award for Innovation Winner of the 2013 CIF/CURT NOVA Award for Innovation ADVERTISEMENT–For Advertiser Information, visit www.STRUCTUREmag.org of working time. • QUIKRETE FastSet Concrete

Mix is a blend of cement with www.foundations.cc www.pile.com/tip specifically graded fine and coarse engineering@foundations.cc sales@pile.com