Interlock Design - Summer 2018 by CMHA

THE OFFICIAL PUBLICATION OF THE INTERLOCKING CONCRETE PAVEMENT INSTITUTE

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volume 24 number 3

CALIFORNIA LEGACY PAVER PROJECT ISSUE COLMA STREETS AT 20 YEARS ORACLE’S PAVER UPGRADES PICP EDGE RESTRAINTS

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Interlocking Concrete Pavement Institute 14801 Murdock Street, Suite 230 Chantilly, VA 20151

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NEW FREE CONTINUING ED PROGRAMS

® EXECUTIVE DIRECTOR: Charles McGrath, CAE PUBLISHING DIRECTOR: Dennis Smith EDITORIAL DIRECTOR: David R. Smith DESIGNER: Amy Liss

High-sloped paver of streets entering Colma’s residential neighborhood have performed well for the past 20 years under vehicular traffic.

5 the

contents

FEATURES 05

COLMA STREETS TAKE THE LONG ROAD TO PERFORMANCE MAINTAINING LONG-TERM SUCCESS WITH INTERLOCKING CONCRETE PAVERS

Photo Credit: Belgard

SUMMER 2018

CONTRIBUTING EDITOR: Robert Bowers, P.Eng.

14801 Murdock Street, Suite 230 Chantilly, VA 20151 Tel 703.657.6900 Fax 703.657.6901 Email icpi@icpi.org ICPI Canada P.O. Box 1150 Uxbridge, ON L9P 1N4 Canada SUBSCRIPTION AND MEMBERSHIP: Qualified design professionals can receive a complimentary subscription — email us at icpi@icpi.org. For further information about this publication or about membership in ICPI, write to the appropriate address, call 703.657.6900 or fax 703.657.6901. Send story submissions for consideration to dsmith@icpi.org. Manage your subscription at www.icpi.org. Interlock Design is published quarterly by the members of the Interlocking Concrete Pavement Institute (ICPI) for producers, suppliers, contractors, specifiers and users of interlocking concrete pavements. The opinions expressed in Interlock Design articles are those of the authors and do not necessarily represent the position of the editor or ICPI.

DEPARTMENTS ICPI Webinar Seminars

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02 INTERLOCKUTOR MISSIONARY WORK 15 ENGINEER’S VIEW FASTER EDGE RESTRAINTS FOR PERMEABLE PAVEMENT

ADVERTISING DAN HARTZOG danH@llmpubs.com | 503-445-2229 PAUL VOLLMER paul@llmpubs.com | 503-445-2222

21 KNOWLEDGE BASE ICPI LAUNCHES FREE CONCRETE PAVER CONTINUING EDUCATION COURSES FOR DESIGNERS

DESIGN AMY LISS amy@llmpubs.com | 503-445-2238

23 ASTM REFINES THE SEGMENTAL CONCRETE PAVEMENT SLAB STANDARD

The acceptance of advertising in Interlock Design magazine does not constitute or imply the endorsement or recommendation by ICPI or its members, staff, editors or the publishers of any product or service mentioned, referenced or advertised in the publication. ICPI accepts no responsibility for any claims made in any advertisement. ICPI further reserves the right to refuse to accept any advertisement.

25 ICPI DELIVERS LEADING TECHNICAL AND EDUCATION RESOURCES FOR DESIGNERS 27 MAIN EVENTS

ISSN 1087-9862

interlockutor Missionary Work

David R. Smith

tate departments of transportation (DOTs) rely on millions of tax dollars for road construction and maintenance. They also look after thousands of structures including bridges. For decades, DOTs are immersed—and one might say entrenched—in design, maintenance and improvement of asphalt and concrete pavements. These are mostly highway pavements. Most DOTs look after local roads as well, especially if they are national or state routes passing through a city or town. About one fourth of all roads are urban, so some portion of this percentage is under state DOT care. While the percentage of their total road inventory likely varies from state-to-state and provinceto-province, urban roads represent an opportunity for interlocking concrete pavements (ICP). Here is a story from the New York State DOT (NYSDOT) who made a new path for ICP. In 2004, the U.S. Federal Highway Administration contacted the NYSDOT requiring removal of ICP from pavement use due to crosswalk failures. This was likely due to problems from a federally funded road project. In the fall of 2005, at the request of ICPI, a task force was created to implement new specifications and subbase requirements to allow ICP. In 2006, provisional ICP specifica-

tions were written with drafts of typical sections for ICP crosswalks in high use areas. The drafts included a 12-inch thick crushed stone subbase, 8 inches of concrete, ¾ inch sand-bitumen setting bed and adhesive under 3 1/8-inch thick (80 mm) thick pavers in a herringbone pattern. The paver thickness was increased from 2 3/8 (60 mm) to 3 1/8 inch as recommended by ICPI. The NYSDOT found a trial location, where a crosswalk(s) in a street could be built. The street had about 8,000 average annual daily traffic (AADT) and this provided a pilot project to monitor the success of the draft specifications. In 2007, the State Historic Preservation Society decided that ICP must be used to replace the pavement on Main Street in East Aurora, NY. AADT was over 20,000 with 10% to 12% truck traffic. This equates to roughly 10 million equivalent single axle loads (ESALs) over 20 years

Four blocks of interlocking concrete pavement are paved on Main Street in East Aurora, New York in 2009.

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assuming 1% annual traffic growth. This then becomes NYSDOTâ&#x20AC;&#x2122;s pilot project. It was built in 2009 with five lanes, curb to curb ICP for about 4 blocks or about 1000 feet. The project involves over 250,000 pavers or over 55,000 sf. After three years of monitoring, the pilot project was deemed acceptable in 2012. NYSDOT issued a new Standard Specification 601 for Architectural Pavements (see their 2016 Standard Specifications Section 601), as well as standard drawings (sheet M601-01 in the 2015 collection of New York State Standard Sheets). In 2017, the NYSDOT reported that the East Aurora ICP continues to perform well with the additional blessing of no utility cuts in the pavement. The diligence of an NYSDOT advocate, Jim Patnaude, Associate Engineering Materials Analyst, Materials Bureau in Albany, was a prerequisite to the ICPI becoming involved. While the state specification is only for concrete bases, it is a start. The next step might be writing design guidance and specs for lower traffic areas that include less expensive, dense-graded aggregate bases and those stabilized with asphalt or cement. While design guidance for these areas is available in a national design standard (see ASCE 58-16 Structural Design of Interlocking Concrete Pavement for Municipal Streets and Roadways), DOTs would embrace ICP more readily if the industry committed to full-scale load testing. This type of validation is done daily by several DOTs and universities across the U.S. and Canada for asphalt and concrete pavements. Since DOTs have great influence on municipal road specifications, this investment could make DOT and ICPI missionary work on local road applications turn into a Reformation.

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Main Street in 2014.

Main Street in 2017.

SUMMER 2018

 COVER STORY

Colma Streets Take the Long Road to Performance

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ecause Colma, California sits on rolling hills just south of San Francisco, it became the unfortunate recipient of the victims of the devastating 1906 earthquake. There are more buried among sprawling, but elegant cemeteries than those alive in this hamlet. In 1998 the streets and sidewalks within the small residential area supporting about 1,600 citizens was adorned with interlocking concrete pavement. With high-slope streets, some as high as 18%, the impressive project was included in an August 2006 article on sloped pavement applications in this magazine. According to Brad Donohue, Colma’s Director of Public works since the late 1990s, the interlocking concrete pavement application was controversial. Some doubted that the pavers would remain stable under traffic on such high slopes. There is no sign of movement on the sloped streets and traction loss has never been a problem. Besides consistent widths among the sandfilled joints, surface stability can be likely be attributed to the 45° herringbone pattern. Other factors working in favor of longevity and no surface distresses is mostly car traffic, a mild climate, and sandy, well-draining soils with R-values between 65 and 70. The longest street, F Street, used a cement stabilized soil subgrade to compensate for a high-water table that sometimes rises during the rainy, winter season and could potentially weaken or alter the pavement subgrade. Mr. Donohue noted that if the 20-year old streets were paved with asphalt, they would have already applied a slurry or chip seal in the first 8 to 10 years. Within the next 10 years, there would more than likely be asphalt surface milling and fill, or an overlay. This suggests that the life-cycle cost of the Colma’s pavers would likely be lower than asphalt after another 15 or 20 years with

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High-sloped paver of streets entering Colma’s residential neighborhood have performed well for the past 20 years under vehicular traffic.

another cycle of asphalt milling and overlay. Given the excellent condition of the pavers, this is a reasonable life cycle cost forecast. He noted, regarding costs in long term maintenance and rehabilitation to the residential roadways, Colma is definitely “ahead of the game” on street maintenance costs by using concrete pavers. Mr. Donahue said that municipalities need to take the long view when it comes to pavement maintenance. Streets will be

maintained in perpetuity as they will very likely be around for hundreds of years. Therefore, selecting long-lasting, 40+ year materials such as interlocking concrete pavement should be considered. Well over a mile of streets and twice that length of sidewalk pavers (about 200,000 sf ) were supplied and manually installed by ICPI members on a 4 inch (100 mm) thick Caltrans Class 2 base over a compacted soil subgrade. All of the pavers were manually placed. Mr. Donahue said that tree roots lifted some of the sidewalk pavers over the years. The pavers were removed, roots addressed, and the pavers reinstated. The streets have seen no lifting from tree roots. He said that the townâ&#x20AC;&#x2122;s streets are surveyed every two years and condition data is collected and sometimes used to obtain maintenance grants. He was pleased to learn about a pavement condition survey

The Town of Colma realized lower maintenance costs from interlocking concrete pavement over 20 years compared to asphalt. This will likely result in overall lower life-cycle costs over 30 to 40 years.

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COVER STORY

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system available as ASTM E2840 Standard Practice for Pavement Condition Index Surveys for Interlocking Concrete Roads and Parking Lots to use for pavement asset management. This standard practice provides a guide for surveying and rating the condition of interlocking concrete pavements. Condition surveys and resulting maintenance budgeting for street maintenance are normal to most municipalities and this ASTM standard enables comparisons on performance among asphalt, concrete and interlocking concrete pavement streets. For Colmaâ&#x20AC;&#x2122;s paver streets, a very good condition rating would only reinforce the obvious superior performance, plus adding to neighborhood character. This is performance that asphalt and concrete can never achieve.

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The paver sidewalks made tree root repairs easier than demolishing and replacing cast-inplace concrete slabs.

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Intersections used light colored pavers to mark crosswalks, thereby eliminating repeated paint applications.

 FEATURE STORY

SUMMER 2018

Maintaining Long-term Sheryl S. Jackson

Success with

Interlocking Concrete Pavers SOFTWARE GIANT ORACLE FORECASTS CONTINUED USE OF CONCRETE PAVERS AT THEIR HEADQUARTERS.

Oracle’s headquarters near San Francisco includes over 35,000 sf of concrete pavers.

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he 66-acre campus for Oracle’s U.S. headquarters next to San Francisco Bay offers more than just office space for its employees in eleven campus buildings. Built on the San Francisco Bay, the office buildings, conference and fitness centers are embraced by a synthetic lake, trails and concrete paver walkways. Oracle began building in 1989 with eventual campus completion in 2002. Because aesthetic features were an important factor in the original design, special attention was given to landscaping and hardscaping to ensure the campus was visually appealing to employees and visitors. “Hardscape makes up 5.13 acres of our campus and

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interlocking concrete pavers represent between 15 and 20 percent of the hardscape,” says George Denise, Director of Operations and Director of Sustainability. In addition to patio areas, pavers are used for three driveways, walkways connecting the building and the Willow Walk, a half mile, 6 to 8-foot wide walkway around the lake, he explains. Willow Walk expanded about 12 years ago with additional features such as large sandstone blocks forming a low wall along the walkway. “The combination of the hardscape, landscape and water creates a pleasant area for employees to walk and enjoy being outside during the workday,” explains Mr. Denise.

Willow Walk, a half-mile, paver path around the campus lake, continues providing a relaxing ambiance for employees and visitors.

Water also presents a challenge, especially in the Willow Walk area, says Mr. Denise. “We should have a base with 1-inch of sand but there are areas of the walkway where we have only silt. The base has washed away.” The combination of a high-water table and improper cleaning with a power washer contributed to the disappearance of the pavers’ base, he says. “It’s amazing that it has lasted 12 years.” European Paving Designs in San Jose, California anticipates repairing one of the driveways and sections of the Willow Walk for Oracle. “One of the challenges with long-term interlocking paver installations in Continues on page 11

KNOWLEDGE COVER FEATURE STORY STORY BASE SUMMER 2018

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Besides developing a maintenance plan, Oracle maintenance staff switched from power washing to a rider/scrubber machine to maintain walks, driveways and the plaza shown here.

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a campus setting is improvement in technology over the years,” says Randy Hays, CEO and founder of the firm. Advances in manufacturing that enables consistent paver joint sizes, technical research leading to guidelines helps ensure the best performance. In addition, development of new materials can be applied to new projects and repairs. ASTM C144 jointing sand is an example of a material that European Paving Designs will use in the Oracle repairs that was not available 25 years ago. “Plaster sand was used, which doesn’t meet today’s guidelines,” says Mr. Hays. Plaster sand is finer than C144 sand (also known as mason sand). Plaster sand doesn’t encourage interlock among pavers and tends to wash out easily, and more so from power washing. To meet ICPI guidelines for aspect ratio (i.e., length divided by thickness), pavers for the

driveway repair will be 4 x 8 x 3 1/8-inch thick pavers with a 4-inch thick compacted, crushed aggregate base under 1 inch of bedding sand. This provides more support than the current installation, he adds this is also the minimum base thickness recommended by ICPI. A soil engineer assisted in the assessment of Oracle’s existing paver installations to ensure that the contractor and owner knew exactly what repairs were needed to avoid future failures. “We don’t typically work with soil engineers in all projects because we typically enter at the bid stage rather than the design stage,” explains Mr. Hays. “When we handle design-build projects that start two years before construction, we include engineering reports as part of educating the team of owners and architects involved in the project to make sure Continues on page 13

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COVER STORY FEATURE STORY

Feature Story continued from page 11

SUMMER 2018

everyone understands the importance of developing specifications that take all factors into account including soil, water issues, landscape features and the specific use of the pavement.” Maintenance is a key issue for long-term installations of interlocking concrete pavers, points out Mr. Denise. “As we renovate areas, we want to make sure they are properly maintained, which includes regular preventive maintenance,” he says. “This will prevent the need for extensive repairs in the future.” He is developing a plan to ensure that all areas are evaluated for bedding sand replacement over the next three years. “We do have a major cleaning challenge because we have a resident population of Canadian geese that necessitates cleaning Willow Walk regularly,” explains Mr. Denise. “For a long time, a power washer was used to clean the area, which washed away the sand and crushed rock under the pavers.”

“

The purchase of a rider/scrubber that uses a water spray and rotating brush to clean the pavers, and suctions excess water from the surface for reuse not only cleans the pavers, but does not wash away sand and base material. “We recommend inspections of all pavers at least twice each year,” suggests Mr. Hays. “Look at the pavement in early spring to identify areas that need attention and make repairs before any big change in weather.” In some areas of the country, that might be a rainy or winter season, he points out. After these, check the pavement again for any damage that needs to be corrected. He adds, “With proper installation and maintenance, an interlocking concrete paver installation should last for generations.”

Advances in manufacturing that enables consistent paver joint sizes, technical research leading to guidelines helps ensure the best performance. In addition, development of new materials can be applied to new projects and repairs. Randy Hays - European Paving Designs

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SUMMER 2018

ENGINEER’S view

Faster Edge Restraints for Permeable Pavement in Pedestrian & Residential Driveways By David Smith

Metal edge restraints replaced concrete in this residential driveway.

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ermeable interlocking concrete pavements (PICP) typically use cast-in-place concrete curbs for parking lot, alley and street applications. Some years ago, edge restraints made from metal or plastic were developed for PICP pedestrian and residential driveways. Time has demonstrated good performance of these fasterinstallation edge restraints that incorporate geogrids for these light-duty applications.

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Photo courtesy of Fred Adams Paving, Inc.

Start with a Firm Foundation PICP for pedestrian and driveway applications consists of a base foundation or reservoir of crushed, washed, opengraded aggregate to store and infiltrate water. Depending on quarry sources, aggregate sizes generally close or within the ASTM No. 57 gradation are adequate. The washed ASTM No. 57 gradation follows:

Sieve Size

Percent Passing

1 1/2 in. (37.5 mm)

100

1 in. (25 mm)

95 to 100

1/2 in. (12.5 mm)

25 to 60

No. 4 (4.75 mm)

0 to 10

No. 8 (2.36 mm)

0 to 5

No. 57 aggregate typically has a porosity of 35% to 40%. This porosity means that 3 inches (75 mm) of compacted aggregate thickness stores about an inch (25 mm) of water. The minimum recommended base thickness for pedestrian uses is 6 inches (150 mm) and 8 inches (200 mm) for driveways. These are often thicker over slow draining soils for structural support and for water storage. While used in vehicular applications, a subbase (under the base) consisting of larger size, open-graded aggregate (e.g., washed ASTM No. 2, 3 or 4 stone) is omitted for pedestrian and residential driveway applications due to no or much lower vehicular loads. Caveat: When 8 inches thick or thicker, some No. 57 stone gradations move and shift during compaction in large areas due to lack of confinement. This increases compaction time and in some instances, precludes use of wheeled equipment on it. In such cases, a minimum 6-inch thick subbase of the larger size aggregate under a

4-inch (100 mm) thick No. 57 base provides a more stable and compactable foundation. When placed, the No. 57 base does not â&#x20AC;&#x2DC;self-compact.â&#x20AC;&#x2122; In fact, no aggregate bases, dense or open-graded, self-compact. No. 57 must be compacted in all installations to maximize stability and reduce future settlement. Compaction is best achieved with vibratory plate compactor with a compaction indicator. Prior to base placement, some applications may have geotextile placed over the subgrade and covering the walls of the excavation. Geotextile provides helps attenuate sideways and downward movement and loss of the aggregate into the soil during compaction.

Three Installation Methods According to three edge restraint manufacturersâ&#x20AC;&#x2122; literature, three installation methods are presented after compacting the No. 57 base layer in maximum 8-inch lifts. The first method applies the edge

restraints with geogrid directly on the compacted No. 57 base. The resulting elevation and slope must be carefully monitored since the edge restraints rest on it. After placing these, a 2-inch (25 mm) thick layer of washed ASTM No. 8 stone (or similar gradation) is screeded smooth on the geogrid. When the restraints themselves are not used as guides for screeding, 2-inch high screed rails may need to be placed on the No. 57 layer to enable bedding layer screeding. During rail placement, they may be adjusted slightly for elevation and slope. Obviously, after screeding the bedding layer around the rails, the voids left after the rails are removed are filled with additional bedding stone and leveled.

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ENGINEERâ&#x20AC;&#x2122;S VIEW

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This restraint placed on the No. 57 base consists of an L-shaped edge with a separate plate under it that clamps the geogrid via screws. Temporarily placed wood provides consistent parallel spacing between opposite restraints while fastening the geogrid. Two top photos courtesy of Fred Adams Paving, Inc.

The bedding layer is screeded between the edge restraints while the edging rests on the compacted base. The edge restraints or screed rails may be used as shown here.

The second method places edge restraints and geogrid directly on the screeded bedding layer. The pavers are then installed, filling the joints with washed ASTM 8, 89 or 9 stone, and compacted. This method does not contain the bedding layer so there needs to be consideration given to its containment outside the paver field, thereby reducing the risk of spreading and settling.

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Geogrid comes fastened to the plastic edge restraint and both are placed on the bedding layer.

Middle and bottom photos courtesy of SEK Surebond

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1 Third Method Step 1 Set geogrid on the base with bedding stone screeded over it.

Step 2 Edge restraint is temporarily held in place with metal stakes while bedding layer is screeded.

Step 3 Wrap the geogrid around the edge restraint onto the bedding layer.

Step 4 Pavers are installed to the edge restraint, filled with jointing stones.

4 All photos on this page courtesy of Pave Tech, Inc.

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SUMMER 2018

The purpose of the bedding layer is to choke or lock into the geogrid and into the No. 57 base surface when compacted. If a slightly smaller gradation for bedding is used such as ASTM No. 89 or 9, it should be tested off site or in a mock-up to be sure it chokes firmly and permanently into the compacted No. 57 base surface. Again, for all methods, the bedding layer is not compacted. This layer receives compaction when after the pavers are placed and joints are filled with washed ASTM No. 8, 89 or 9 stone, or similar gradations. Paver manufacturers often recommend the appropriate gradation based on the joint widths formed by the paver pattern. ASTM gradations are shown below (per ASTM D448 or C33) as a guide for applying to PICP joint widths.

Sieve Size

ASTM No. 8

inches (mm)

ASTM No. 89

ASTM No. 9

Percent Passing

½ (12.5)

100

Percent Passing

0.4 (9.5)

85-100

90-100

100

No. 4 (4.75)

10-30

20-55

85-100

No. 8 (2.36)

0-10

5-30

10-40

No. 16 (1.18)

0-5

0-10

0-5

No. 50 (0.3)

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Uncompacted pavers should be set about an inch above curbs and protrusions, as this height will be substantially reduced after compaction. The final elevation of compacted pavers should be ¼ inch above adjacent surfaces as additional settlement will occur, typical to all pavements made with aggregate bases. At a minimum, the vertical portion of the edge restraints should cover at least the bottom inch of the border pavers to help ensure stability. In conclusion, all the methods accelerate installation time compared to forming, pouring and finishing cast-in-place concrete. ICPI certified contractors with a PICP specialist designation likely can provide additional information on installation advantages and cost savings for each method, plus provide project examples, as well as that from edge restraint manufacturers. PICP specialist installers and PICP edge restraint suppliers can be found on www.icpi.org.

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SUMMER 2018

KNOWLEDGE base ICPI Launches Free Concrete Paver Continuing Education Courses for Designers

he Interlocking Concrete Pavement Institute (ICPI) launched free continuing education courses on concrete pavers hosted online by AEC Daily, one of the largest sources of continuing education for design professionals. The three new courses are approved by AIA/CES and ASLA/CES for continuing education credits towards professional licensure. A brief description of each program follows.

Structural Design of Interlocking Concrete Pavers for Municipal Streets and Roadways

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Interlocking concrete pavers (ICP) spread applied loads via interlock among units. The surface shares applied wheel loads as a composite rather than as individual units. This structural behavior enables application of flexible pavement design methods. This course instructs the user on how to apply the American Society of Civil Engineers (ASCE) 58-16 national design standard on ICP structural design as well as ICPI Tech Spec 4, also on structural design which includes rigid pavement design. The course also

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provides design examples using different soils, traffic loads and pavement materials. In addition, it notes structural design and life cycle cost analysis software available from ICPI. This 77-slide presentation counts for 1.25 CE units.

Inspection of Permeable Interlocking Concrete Pavement Systems There are many steps required to ensure a well-executed PICP project and this course establishes the minimum requirements for construction inspection. It addresses preconstruction meeting details, requirements for submittals and site inspection points from project start to completion. Various testing methods and inspection criteria are presented while stressing the importance of having an ICPI-trained contractor on the job site. The presentation was developed from ICPI member contractor, staff and consultant expertise on PICP construction. This 53-slide presentation counts for 1.0 continuing education credit.

Permeable Interlocking Concrete Pavement (PICP) Maintenance Maintenance is the number one question by PICP owners and operators. Since its debut in the late 1990s, PICP has seen a growing role in the restoration of natural hydrologic processes in urbanized areas because it collects stormwater where it falls and slowly infiltrates it into the ground. PICP is used by project owners to comply with National Pollutant Discharge Elimination System regulations. But in order to be effective, PICP must be properly and regularly maintained. This course addresses inspection points, test methods, equipment, repairs and reinstatement to ensure

PICP consistently contributes to green infrastructure and stormwater management goals. This 70-slide presentation counts for 1.0 continuing education credit. To access the courses, designers can visit https://aecdai.ly/icpi and search for â&#x20AC;&#x153;ICPI.â&#x20AC;? Each presentation is followed by a quiz. Participants must pass the quiz to earn continuing education credits. For additional ICPI resources, designers can visit www. icpi.org.

KNOWLEDGE BASE SUMMER 2018

ASTM Refines the Segmental Concrete Paving Slab Standard

ASTM helped clarify its segmental concrete pavement standard, especially for applications requiring tighter dimensional tolerances such as bitumen-set applications shown above and for vehicular applications.

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STM recently updated C1782 Standard Specification for Segmental Concrete Paving Slabs and the changes provide additional clarification to this product standard first introduced in 2016. First, the title has changed where the word ‘Utility’ that originally appeared before ‘Segmental’ is now removed. This means the standard applies to all types of paving slabs that meet the dimensional envelope defined in it. This envelope is described as a face area greater than 101 in. 2 (0.065 m2) and the length divided by thickness greater than 4. The minimum thickness is 1.2 in. (30 mm), and the maximum length and width dimensions are 48 in. (1220 mm). Second, the standard’s scope states that the slabs are intended for pedestrian and roof applications. However, a (non-mandatory) note was added stating that slabs can be used in vehicular applications but may require alternate material properties (e.g. higher flexural strength than the minimum average of 725 psi) or structural support (e.g. stiffer bases), or both. Third, rather than introduce an additional, new set of tighter dimensional tolerances required for some applications, a (non-mandatory) note was inserted to inform readers that applications on a sand-bitumen setting bed or set on pedestals for roof applications may require tighter dimensional tolerances for thickness and warpage than those provided in the standard. Tighter tolerances, if needed, should be specified separately. This provides flexibility for the manufacturer and specifier to apply tighter tolerances when needed for slabs installed using these two setting methods, or in other applications. To purchase ASTM C1782 visit https:// www.astm.org/Standards/C1782.htm.

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ICPI Offers 23 Free Tech Specs on Segmental Concrete Pavement Design, Construction & Maintenance

egun in 1993, ICPI continues developing a stable of free Tech Spec technical bulletins for designers and contractors on www. icpi.org/resource-library/find-tech-spec. These bulletins represent ICPI member consensus on best practices for design, installation and care of concrete pavers, permeable pavers, slabs and grid pavement.

Among the 23 Tech Specs available, the most popular visited on www.icpi.org are 2: Construction of Interlocking Concrete Pavements 4: Structural Design of Interlocking Concrete Pavement 15: A Guide for the Specification of Mechanically Installed Interlocking Concrete Pavements 1: Glossary of Terms for Segmental Concrete Pavement 8: Concrete Grid Pavements The 23 bulletins are updated based on research, changes to national standards and industry experience. The update month and year appears on the bottom cover page. New bulletins are announced in this magazine as well as on www.icpi.org.

FEATURE STORY KNOWLEDGE BASE SUMMER 2018

ICPI Delivers Leading Technical and Education Resources for Designers

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Visit https://www.icpi.org/designers

or landscape architects, civil engineers and architects designing and specifying segmental concrete pavement, ICPI provides rich technical resources in support of its manufacturing members who made over 800 million square feet of pavers, paving slabs and planks last year. ICPI provides many free resources and education opportunities to help designers. These are listed on www.icpi.org/designers. Here is a list of many entries: Tech Specs—23 illustrated technical bulletins on best practices for design, construction and maintenance.

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Over 90 detail details drawings in PDF or DWG format describing assemblies for interlocking concrete pavements, permeable interlocking concrete pavements, concrete grid pavements and precast concrete paving slabs. Guide Specifications—for the above assemblies patterned after CSI’s three-part (general, products, execution) structure with MasterFormat numbering: 16 specs for U.S. and 16 for Canadian applications. Each provides salient information and notes to the specifier who then modifies the guide specification to apply to specific project conditions.

Construction Tolerances for Interlocking Concrete Pavements—A two-page summary on recommended tolerances for the pavers and bedding layer, base and subbase layers and edge restraint/curbs, plus tolerance measurement guidance. Designed for field use. ICP Inspection Checklist—A construction summary covering planning, submittals, on-site preparation, verification of site conditions, verification of delivered materials, installation of interlocking concrete pavement, quality control, cleaners and sealers, and final inspection. Includes a maintenance checklist. PICP Inspection Checklist—A construction summary covering the pre-construction meeting; excavation; geotextile; impermeable liners; drain pipes/observations wells; subbase, base, bedding and jointing aggregates; edge restraints; permeable interlocking concrete pavers, final inspection. Includes a an in-service inspection checklist. Project Profiles—Examples of concrete paver designs and installations inspire landscape architects, civil engineers and architects. Permeable Pavement Comparison Guide—Explains the advantages of permeable interlocking concrete pavement (PICP) compared to pervious concrete and porous asphalt. Software Programs—Excel based programs for ICP structural design, and life-cycle cost analysis for interlocking concrete pavement and permeable interlocking concrete pavements.

Continuing Education Resources Request a complimentary lunch and learn presentation at your office—A member of ICPI’s Commercial Technical Promotion Team can provide ICPI presentations registered with AIA/CES and LA/CES, as well as professional development hours, or PDHs for civil engineers. Free On-Demand Webinars—Many self-guided, on-demand presentations are registered with AIA/CES and LA/CES. Landscape Performance of Segmental Concrete paving—A Landscape Architecture Foundation on-demand presentation providing exemplary projects delivering environmental, social and economic benefits using Sustainable SITES performance criteria.

Student & Professor Instructional Resources PaveShare Curriculum for Landscape Architecture Students and Educators—Hosted by Land8 as www.paveshare.org, this resource seeks to inspire design thinking and instruct technical know-how through a range of curriculum materials, precedents, presentations, interactive animations and studio projects. Civil Engineering Curriculum—A curriculum package consisting of nine instructional PowerPoint modules on a range of topics on interlocking concrete pavement. Modules include learning objectives and prerequisites, teaching strategies, presentations, supporting technical bulletins, design manuals, publications and software, as well as suggested assignments for students. Contact ICPI for access. In addition, ICPI technical staff are available to answer questions about segmental concrete pavement systems. Send inquires icpi@icpi.org or call 703-657-6900.

SALES PROFILE SUMMER 2018

Segmental Concrete Pavement Product Sales Achieve a Post-Recession High

or the seventh consecutive year, combined sales of segmental concrete pavement products in the United States and Canada have increased, according to the 2018 Industry Sales Profile by the Interlocking Concrete Pavement Institute (ICPI). The 2017 projected total of 750 million sf. is a post-recession high, representing a 2.5% increase from the 721 million sf. in 2016 and a 63% increase from the low of 472 million sf. in 2010. The 2017 mark is approaching the all-time high for sales (800 million sf.) established in 2006 prior to the recession. The study surveyed 26 manufacturers representing 25% of the producing companies in the U.S. and Canada. These companies own approximately 54% (136) of the paver producing machines in the two countries. The survey was conducted by Industry Insights, an independent research consulting firm based in Dublin, Ohio. The estimated combined U.S. and Canadian use of concrete pavers in 2017 equaled 2.07 sf. per person compared to 1.94 sf. in 2016. Sales growth was 2.8% in the U.S. and 0.2% in Canada among survey participants, compared to 2016 for all segmental concrete pavement products. Products for residential use represented 77.9% of sales, while commercial applications comprised 12.5% of

sales. Public/government and industrial sales were 8.2% and 1.4% respectively. Interlocking concrete pavers comprised 81.3% of products sold by survey participants, while paving slabs were the second-most popular product at 10.2%. Permeable interlocking concrete pavers represented 5.8% of sales, followed by concrete grid pavers at 0.4% and other products at 2.3%. The report attributed low interest rates and energy costs, modest growth in new home construction, increased infrastructure investments by the public sector, and increases in commercial construction as key contributors to growth for the U.S. segmental concrete pavement industry. Canada presented a mix of growth or contraction depending on the region. The report also pointed out, “While difficult to measure impacts on sales, another factor attenuating industry growth is lack of a sufficient labor force to install segmental pavement systems.” This skilled workforce shortage has been identified in other recent ICPI studies, causing the Institute to create a workforce development program that will launch later this year. The complete 30-page study is available for purchase by visiting www.icpi.org/shop.

KEY FACTS Combined U.S.–Canada Data Overall Concrete Paver Sales y Estimated 750.1 million sf. y 2.5% increase over 2016 y 77.9% projected (584.3 million sq.) sold to the residential market

Permeable Interlocking Concrete Pavement y Estimated 59.0 million sf y 7.9% of all (ASTM) paver sales y 58.1% sold to the commercial, municipal and industrial markets y PICP represents a higher portion pf product mix in the U.S. (6.4%) than in Canada (2.1%)

Concrete Paving Slabs y 10.2% of all (ASTM) paver sales, up from 9.6% y 20.8% for commercial, municipal and industrial applications

esign®

y Slab production markedly greater in Canada representing 29.5% of total production mix compared to 7.3% in the U.S. y Concrete Grid Pavements

interloc

y Estimated 6.0 million sf. y 0.4% of the total segmental concrete pavement production y 58.5% sales to the commercial, municipal and industrial markets

InterlockDesign.org



the MAIN events DATE

EVENT

SEPT

Southwest Regional Installer Championship

Chandler, AZ

10–13

2018 ICPI Summer Meeting

Vancouver, BC

16–19

2018 International Conference on Concrete Block Pavement

Seoul, Korea

16–17

Concrete Paver Installer Course – HNA

Louisville, KY

16–17

Concrete Paver Installer Course (Spanish) – HNA

Louisville, KY

16–17

Residential Paver Specialist Course – HNA

Louisville, KY

16–17

Commercial Paver Specialist Course – HNA

Louisville, KY

PICP Specialist Course – HNA

Louisville, KY

17–19

2018 Hardscape North America Trade Show

Louisville, KY

6–7

Commercial Paver Specialist Course – ICPI Northern California Chapter

Sacramento, CA

PICP Specialist Course – ICPI Northern California Chapter

Sacramento, CA

14–15

Concrete Paver Installer Course – Belgard

Little Rock, AR

27–28

Concrete Paver Installer Course – ICPI Northern California Chapter

Reno, NV

3–6

ICPI 25th Annual Meeting (2019)

Charleston, SC

OCT

NOV

MAR

LOCATION

ASCE WEBINARS DATE

WEBINAR TOPIC/SPEAKER

TIME

Sept 24

PICP Design, Construction & Maintenance / Dave Hein, P.Eng.

11:30–1:00 EST

Jan 9

Best Practices and Lessons Learned from the Design and Construction of Interlocking Concrete

11:30–1:00 EST

Pavements / Dave Hein, P.Eng. Mar 8

PICP Design, Construction & Maintenance / Dave Hein, P.Eng.

11:30–1:00 EST

Visit www.asce.org for registration information.

ADVERTISERS IN THIS ISSUE Alabama Pallets. .................................20

Pave Tool Innovators ........................ 22

Techniseal, Inc.................................... 14

BP Pro ............. Inside Front Cover, 20

Pavers by Ideal .................................. 20

Topwerk American, LTD .................. 26

Besser .................................................... 6

Rampf Molds Industries, Inc. .......... 23

Unilock ...................................................4

Columbia Machine, Inc. ....................16

SEK, Inc. ............................................. 12

Wuerschum North America, Inc..... 24

Kobra Molds, LLC ..............................19

Slab Innovation, Inc. ............................6

Oaks Landscape Products ..............12

Solomon Colors, Inc......................... 13

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