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HNA Draws Record Numbers to Louisville

The 9th Annual Hardscape North America trade show, Oct. 21–23, 2015, drew record numbers of contractors and dealers in Louisville, KY. With over 9,300 landscape and hardscape contractors in attendance for HNA and GIE+EXPO, attendees and exhibitors enjoyed a successful event. ICPI, the association for the segmental concrete pavement industry and producer of HNA, saw a 4 percent increase in attendance this year over last.

Installer Championship

The HNA Installer Championship had 12 teams battle at the outdoor pavilion at the Kentucky Exposition Center. Each team was challenged to demonstrate its creativity, skill and efficiency in paver and segmental retaining wall installation. On Friday afternoon, four finalist teams competed against each other with 90 minutes on the clock.

The finalists were:

  1. Team Skyline Landscaping of Oak Leaf Landscaping
  2. Team Two Brothers of L&S Hardscapes, LLC
  3. Team Two Friends of A+ Landscaping
  4. Team D&B of Cooper Pavers, Inc.

In the end, Team D&B earned the title of HNA 2015 Installer Champion.

Click on the image above to see more photos from the HNA 2015 Installer Championship.

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The Joy of Disruptive Things

Disruptive technology: One that displaces an established technology and shakes up the industry, or a groundbreaking product that creates a completely new industry. Examples: cellphones, personal computers and flat screens. From www.whatis.com.

Disruptive innovation: One that helps create a new market and value network, and eventually disrupts an existing market and value network (over a few years or decades), displacing an earlier technology. Examples: Uber, Wal-Mart and iTunes. From www.innosight.com.

Does the concrete paver industry have a disruptive technology? Maybe so, and it might be carbon curing. In very simple terms, carbon curing is using carbon dioxide to cure concrete instead of air. CO2 is captured into the concrete, holding some generated by cement production. This sounds good given the rising CO2 levels in the atmosphere and the broader implications for global warming, climate change, rising sea levels, etc. Fortunately, the segmental concrete pavement industry takes a smidgeon of comfort in knowing that 95 percent of CO2 emissions comes from burning fossil fuels to heat/cool buildings and from operating ships, trains, planes and automobiles.

A requirement fixed in concrete manufacturing is curing time. While concrete never stops curing, 28 days was established decades ago for curing time prior to testing for strength, absorption/density, and freeze-thaw deicer resistance. Concrete pavers often take less than 28 days to achieve the minimum 8,000 psi (55 MPa) unit compressive strength required in ASTM C936 or the minimum 7,200 psi (50 MPa) cube compressive strength in CSA A231.2. Nonetheless, significant sums of venture capital are being invested into carbon curing of concrete pavers because it presents a disruptive 24 hours for curing instead of 672.

What does a 24-hour cure time mean regarding substantive efficiency increases? Most of our readers haven’t experienced a concrete paver plant. It consists of millions of dollars of equipment and computers that mix concrete and quickly form it into a layer of 30 to 40 pavers within a steel mold. Paver production machines can’t go much faster to reduce cycle times for vibration and compaction of wet concrete within the mold. Perhaps this could be reduced to just a few seconds if the vibration of the concrete mix happens before it enters the production mold. Another option is placing more production machines in a plant (next to another or in line) such that daily throughput is quadrupled or taken higher. This implies a corresponding expansion of curing areas within a plant, meaning larger plants.

But let’s assume that the part of the plant that makes concrete units increases output that corresponds to the curing rate output now at one day instead of 7 to 28 days. That suggests factories won’t need much time or space next to them in “the yard” to store pavers. While a larger indoor space might be needed for higher production output, plants can make and ship paving units pretty much on order, even very large orders. Inventory management becomes just in time. The need for the yard next to the plant decreases, making inventory less important, and financing costs to create it diminish.

An innovative rearrangement of old commodities like cement and CO2 present a disruptive framework. The disruption from carbon curing extends to rearranging the plant and reprogramming computers that control mixing, batching and cycle times so equipment paces with faster curing and packaging times, and on multiple machines. This seems like the difference between using radar for airport air traffic control (linear sequencing) and more efficient GPS. The latter requires operational simultaneity in a four-dimensional space with new rules for aircraft spacing on approach, landing, take-off and hand-off.

The coming disruption within the paver industry could be CO2 curing with shorter curing times. This means rethinking the configuration of existing manufacturing equipment: its extent, layout and software programming. The joy of disruption doesn’t only come from the environmental benefits of CO2 curing. It potentially comes from disruptive pricing. All of this eventually could mean that segmental concrete pavement might have a future with a lower initial cost than asphalt. That disruption is pure joy.

For more information on companies that help reduce carbon emissions from concrete products, watch the following videos:

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Learning Curve

The ICPI Foundation for Education and Research awarded the Landscape Architecture Foundation (LAF) a three-year, $75,000 grant to enhance the Landscape Performance Series (LPS), an online interactive resource that helps designers, agencies and advocates evaluate performance, share best practices and make the case for sustainable landscape solutions.

Launched in 2010, www.landscapeperformance.org showcases evidence-based environmental, social and economic benefits of landscape by sharing information and innovations from the fields of design research and academia, as well as industry and professional practice. Much of the site provides case studies demonstrating landscape performance with detailed information on performance assessment of economic, environmental and social benefits of landscape designs with the human and natural systems with which they interact.

Besides significant visibility for the ICPI Foundation, the grant includes input from the ICPI Foundation by curating case studies with segmental concrete pavement systems and by providing product information. The site’s content will be filterable by landscape system, such as interlocking or permeable interlocking concrete pavements. The most significant aspect of the program will be a new training section that the ICPI Foundation will develop with LAF, “Designing for High Performance,” with the first learning module focused on segmental concrete pavement.

Moreover, the ICPI Foundation has opportunities to share their research and sustainability initiatives within the LPS. This will be in the form of blog posts or a curated “collection” of content as part of the new website. Since its inception in 2000, the ICPI Foundation has sponsored several research projects to better define the economic, environmental and social performance of segmental concrete pavements. The LAF website provides significant visibility for the ICPI Foundation with landscape architects and academics via a website that receives over 90,000 visits annually.

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Grabbing Wallets

When introduced in 2014, the U.S. Green Building Council’s LEED v4 heightened awareness of environmental product declarations or EPDs. Among significant changes to the LEED Materials & Resources credit criteria, LEED v4 now bestows a modest one point for projects with at least 20 EPDs from different construction material manufacturers. Given that buildings and sites typically contain thousands of products, this seems a small requirement by LEED v4.

One intent of this credit is to raise awareness of EPDs among construction material suppliers. This requirement has led many construction materials industries to first create product category rules (PCRs) according to ISO standards. PCRs prescribe requirements for defining the impacts of manufacturing a product, as well as outline the elements of a life-cycle assessment (LCA) of environmental impacts from manufacturing. The LCA forms the basis for creating an EPD.

EPDs list environmental impacts from manufacturing a product. They have been compared to reading a nutrition label on food packaging. Rather than fat, carbohydrates, proteins and vitamins, EPDs list the following impacts: global warming potential (carbon emissions); sulfur-dioxide, ozone and smog-type air pollutants; total energy consumed; use of renewable resources; depletion of non-renewable natural resources; nutrient emissions into waterways; and fresh-water use.

A practical yardstick for measuring these impacts is typically a unit of volume or mass of the finished construction product. For segmental concrete paving units, this is a cubic yard or meter of concrete. Most impacts per cubic yard of concrete are from carbon emissions due to producing cement and from generating electricity to run a manufacturing plant. Obviously, the energy source to make cement and electricity influence carbon emissions. EPDs favor hydroelectric, nuclear, wind and solar energy with lower carbon emissions compared to coal, gas or oil-fueled sources.

Now that ASTM issued a PCR for segmental concrete pavement products, it’s up to manufacturers to conduct LCAs, then produce and publish EPDs on their products. While the market isn’t consistently or even intermittently demanding EPDs from concrete paver manufacturers, the industry is preparing for the inevitable change. California manufacturers will likely be the first with EPDs, since that state imposed a legal mandate to trim carbon emissions. To assist the education process, the ICPI Foundation for Education & Research recently developed a guidebook for manufacturers on creating LCAs and EPDs. ICPI also developed a manufacturing material and energy-use inventory spreadsheet tool for its members.

Comparing EPDs among manufacturing segmental concrete paving products, asphalt and ready-mix concrete requires nearly equivalent PCRs. The asphalt industry will weigh in when their PCR is completed late this year or next.

While LEED and other sustainability evaluation tools have taken modest steps to raise EPD awareness in the North American construction world, where are EPDs ultimately going? They will become a critical source of data that will eventually feed into evaluating environmental impacts from a product’s construction, life and disposal/reuse. This is already happening in the building design world. It’s just starting in the pavement world.

Segmental concrete paving products are in a unique position to offer lower environmental impacts by not requiring huge paving machines and concomitant fuel consumption during construction. During their life, segmental concrete pavements offer immediate reuse in-service, a significant benefit for cities. Asphalt and cast-in-place concrete do not; those materials are removed and landfilled or later recycled.

Quantifying differences among construction, lifetime and end-of-life impacts will become increasingly important to municipal transportation agencies in the coming years.

Aggregates supplies are decreasing in some regions. Asphalt isn’t cheap. Transportation agencies are expected to build, maintain and rehabilitate pavements with less money and make them last longer.

Like Europe, agencies here will eventually move toward bidding material, construction and project maintenance life-cycle assessments. Maintenance pricing and LCA bids will spawn risk assessment/financing companies. (Maintenance price bids are already happening with some ICPI members selling permeable interlocking concrete pavements.)

All of these tools will ultimately save agencies money. LCAs will grab their wallets. That will get their attention.

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Two Worlds Together

In 2010, the Transportation and Development Institute (T&DI) of the American Society of Civil Engineers (ASCE) hosted the first national Green Streets and Highways conference. This came from a need for stormwater managers to learn more about the world of road managers and vice versa. Stormwater managers realize that roads cover about 25% of urban areas, generating significant property damage from water pollution, minor flooding and combined sewer overflows in older cities. Not surprisingly, road managers view stormwater as a lower priority compared to road user safety and efficiency. Also, road agencies generally are larger than stormwater agencies at every level of government, and that typically translates into greater financial, technical and political clout.

Most road agencies view permeable pavement as suitable for car parking lots and alleys with occasional applications in low-volume residential streets. Such projects are at the margins of road agency priorities and their budgets, and many of these applications lie in the private sector. Permeable pavements have yet to be embraced by road agencies because they are seen as new and untried under regular truck or bus traffic. This is where more structural testing and evaluation of hybrid pavements may allow for more passes from higher-weight vehicles. This can place permeable pavement more in the mainstream of the road manager’s world.

Along these lines, moving permeable pavements more into mainstream acceptance and use by road managers will require several components. As noted, first and foremost is accelerated, full-scale load testing to validate the ability to withstand truck traffic. Such testing must result in structural design methods and easy-to-use, reliable thickness charts. While there has been some full-scale load testing for pervious concrete and porous asphalt, a recent full-scale load study by UC Davis on PICP resulted in design charts. This magazine issue includes a summary of the UC Davis work, cost savings implications for designers and where the charts will be used.

The second component is specifications. Cities and county road agencies often rely on, adopt and adapt construction specifications developed by state departments of transportation (DOT). Even provisionally issued specifications by a state DOT tells local road agencies that a particular technology such as permeable pavement has been vetted by knowledgeable experts. There are currently two DOTs that have published PICP specifications; Caltrans and Washington, DC. ICPI assisted in developing these. We hope to do more of this.

The third component is training. There are two sides to the training coin: one is for contractors that results in certification of competent, experienced individuals; the other is inspection training for road agency personnel. ICPI has seen fast growth in PICP classes for contractors and in those receiving a PICP Specialist Designation. This credential is becoming a requirement in local and state agency specifications. To help address this need, an inspection presentation is now available for ICPI members to present to stormwater and road agency personnel.

The fourth component is maintenance/management procedures and costs. A critical maintenance aspect for permeable pavements is regular surface cleaning with vacuum equipment. Permeable pavement will be more readily embraced by state DOTs and especially by local road agencies when existing street cleaning equipment can be used for cleaning. Regularly maintained PICP performs for decades. However, many installations don’t see regular cleaning that results in restoration of the surface infiltration with powerful vacuum equipment and perhaps water. ICPI has funded maintenance research in the past. This includes work by North Carolina State University and the Toronto and Region Conservation Authority. ICPI and its sister organization, the ICPI Foundation for Education and Research, are reviewing more research options for the near future.

This issue’s cover story features another realm where the two worlds of stormwater and pavement are usually close together, and that’s on military bases. These mostly self-contained environments are of such a scale that one person or a small group of people down the hall from each other manage pavements and drainage. There are a growing number of them using interlocking and permeable interlocking concrete pavements. The cover story provides an example of integrating the two worlds of pavement and drainage management from a need to solve flooding problems and pavement rehabilitation.

As industry, academia and governments address the four requirements for permeable pavement that lead to it becoming mainstream road infrastructure, the two managerial worlds will work more closely together. One resource that can support this process is ASCE publishing a new book called Permeable Pavements.

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HNA 2015 Call for Entries

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You can’t win if you don’t enter: 2014 HNA Award winners received substantial exposure of their creations and companies.

Residential and commercial contractors of segmental paving and wall systems are encouraged to enter the Hardscape North America Awards contest. The contest offers contractors significant exposure to their finest projects. Past winners have been featured in this magazine as well as Hardscape, Concrete Products, Concrete International, Landscape and Irrigation, Landscape Architect and Specifier News, and Concrete Masonry Designs. The post-HNA press release announcing the 2014 winners received more than 59,000 headline impressions on Google and Yahoo! news feeds.

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ICPI encourages contractors to take advantage of this opportunity for company and project exposure and promotion. The contest recognizes only the highest quality projects, exemplars of craftsmanship and design using concrete pavers and paving slabs, clay pavers and segmental retaining walls. Award winners will be announced at the HNA 2015 Awards Reception on Thurs., Oct. 22, 2015, at the Kentucky Exposition Center in Louisville, KY.

Visit https://hna.nonprofitcms.org. Questions can be directed to ICPI at 703-657-6900 or to icpi@icpi.org.

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Inspection of PICP Systems

With the rapid growth of permeable interlocking concrete pavements (PICP), there is a pressing need for increased awareness and improved execution of inspections during construction. The greatest needs often emerge in two areas: 1) pre-construction coordination among project owners/manager, designers, product suppliers, testing labs, the contractor and subcontractors; and 2) compaction inspection for PICP system stability and long–term performance.

To better address these and other needs, ICPI released a one-hour PowerPoint presentation on PICP inspection for project inspectors. The presentation also informs designers, job superintendents, crews and product suppliers about inspection aspects common to most PICP projects.

The program is approved for one hour of ASLA and AIA continuing education credit and is also eligible for earning one professional development hour. For ICPI certified installers, this program also earns one hour of continuing education for maintaining certification. For a presentation, contact an ICPI manufacturing member with a request. To find those nearby, visit the home page of http://www.icpi.org and use the “Find a local…” search engine. ICPI members providing the presentation must be ICPI-approved continuing education program presenters.

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Lifetime Achievement

ICPI recently recognized industry leaders Chris Ross and David Bender for a life of significant contributions to the segmental concrete pavement industry.

The ICPI Lifetime Achievement Award recognizes life-long, high-impact contributions to the industry through knowledge, technical innovation, and advocacy. The award emphasizes innovation, dedication of the recipient to safety and well-being of employees, demonstrated leadership, and/or outstanding contribution to the industry from volunteer service to ICPI which promotes growth and advancement of the association and/or industry. The award recognizes noteworthy public service activities at the local, regional, state, national or international levels that bring honor to the industry or to ICPI.

ICPI Chairman David Pitre noted, “Both Chris and David helped lay the groundwork for which our association and industry operates. Without them, our industry would not be where it is today.”

CHRIS ROSS

Chris Ross served as ICPI’s Chairman-elect in 1998 and 1999, and then as ICPI Chairman in 1999 and 2000. With his oversight, he supported the transition of ICPI from a small association management company to Bostrom Corp. who helped grow ICPI from a $700,000 budget in 1998 to more than $2 million in 2007. Under Mr. Ross’ chairmanship, ICPI laid some foundations that their board and committees rely on today. Some of these include the ICPI policy manual, policies on financial reserves, development of the certification courses, and regional meetings. The ICPI Foundation was created while he was chair.

Several groundbreaking projects were supplied by Mr. Ross, including Massey Coal Terminal in Newport News, VA (now owned by Shell). This project led to another landmark project, the Port of Baltimore. The Baltimore project set a successful example among port engineers and engineering consultants, and helped open other U.S. ports to using concrete pavers.

DAVID BENDER

In 1980, Mr. Bender moved from Canada to Texas and established Pavestone Company, now one of the largest paver manufacturing companies in North America. Seven years later he returned to Canada to establish Pavestone Plus (later renamed Navastone) where he worked for the next 20 years. In 1986, Mr. Bender penned a very passionate letter to the National Concrete Masonry Association (NCMA) detailing how pavers are different [than other pavements] and persuaded the need for the industry to support and market pavers accordingly. Long before its inception, his efforts helped lay the groundwork for the creation of ICPI in 1993.

Mr. Bender continued his passion for growing the industry. His company is a charter member of ICPI. Soon after its establishment, Mr. Bender led the association serving as chairman from 1995-1997. He is attributed with several leadership accomplishments that helped shape the association and industry. One of these was the development of the ICPI Certification Program, which today has had more than 25,000 participants. Mr. Bender also directed several marketing efforts to help overcome other barriers to paver sales success. These included the development of the product certification program, a multi-national public relations campaign, municipal products slideshow and a video on mechanical installation.

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Essential Reading

Sponsored by the Low Impact Development Committee of the Urban Water Resources Research Council of ASCE’s Environmental and Water Resources Institute, Permeable Pavements presents a comprehensive, 260-page resource on design, construction and maintenance of permeable pavement systems. This e-book and printed edition represent a significantly updated compilation since Bruce Ferguson, FASLA, wrote Porous Pavements in 2005. ASCE’s book is richly illustrated with photos, diagrams and tables.

Permeable Pavements synthesizes diverse materials and practices using this technology with the help of academics, industry, civil and environmental engineers and scientists. The book benefits from these viewpoints with 17 authors plus 13 contributors and reviewers.

The book’s three primary editors, Bethany Eisenberg, LEED AP, Kelly Collins, PE and David R. Smith provided the structure, fact-checking, graphics and a consistent narrative style. The result is a book that can be used on almost every project.

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The book presents an overview of design considerations common to all permeable pavement systems in the first chapter. Detailed design, construction, use and performance information follow in separate chapters on porous asphalt, pervious concrete, permeable interlocking concrete pavement, grid pavements and some recent proprietary products. Additional chapters summarize maintenance considerations, hydrologic design approaches, essential components for specification writing and key areas for additional research. The book’s extensive use of fact sheets and checklists can be instrumental in design, construction and maintenance by stormwater agencies, designers, contractors and project owners. Appendices also include a fact sheet clarifying information on common concerns, as well as tables summarizing water quality treatment performance and costs.


The downloadable e-book and soft cover print version each retail for $120 ($90 for ASCE members). Visit the “publications” section at www.asce.org to order the book.


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The Results Are In

Two years in the making, the University of California Pavement Research Center in Davis recently released a report on full-scale load testing of permeable interlocking concrete pavement (PICP). The report proposes revised design charts that reduce the thickness of a subbase thickness chart published in ICPI’s 2011 manual, Permeable Interlocking Concrete Pavements. The revised charts from UC Davis provide more cost-effective thicknesses.

The subbase thickness in the 2011 ICPI manual are calculated using the flexible pavement design methodology in the 1993 Guide for Design with Pavement Structures by the American Association of State Highway and Transportation Officials (AASHTO). Well-known among pavement engineers, this book provides methods for calculating dense-graded base thicknesses under roads. The methods do not cover calculations for open-graded bases for permeable pavements. Conservative adjustments to AASHTO methodology were made to develop the 2011 design chart for open-graded materials.

The UC Davis research validates ICPI’s subbase thickness chart while refining it by considering the number of days per year a subbase sees standing water, i.e., 0, 10, 30, 60, 90, and 120 days. The resulting charts present thinner subbases at the lower end of this range of exposure to standing water when compared to the ICPI chart which assumes high exposures to saturated subgrades and subbases. Subbase thickness also depends on other factors such as the amount of soil support and anticipated wheel loads.

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The UC Davis Heavy Vehicle Simulator load tests PICP structures.

In pavement design, the mix of anticipated wheel loads over the pavement’s life are combined and equalized into 18,000-lb axle loads called ESALs or equivalent single axle loads. This load unit provides a consistent measurement that also relates to pavement rutting. To give an idea of an ESAL, an over-the-road tractor-trailer typically exerts 3 or 4 ESALs with one pass over a pavement. The PICP loaded at UC Davis received over 2.5 million ESALs using a machine simulating truck wheel loads. Pictures of the Heavy Vehicle Simulator (HVS) are above, as well as a video of it running dual truck tires on the test track.

In pavement research, the best way to determine how many ESALs define pavement lifespan in years is to conduct full-scale accelerated load testing. In other words, a pavement is loaded with many wheel passes until it fails or is no longer considered useful. UC Davis pavement engineers conducted load testing with an HVS that accelerates loading, accomplishing 20 years of loading in just five and a half months. For PICP, failure is defined as excessive rutting, typically over 1 in. (25 mm). Interestingly, none of the concrete pavers cracked while the pavement was loaded with truck tires at the UC Davis testing facility while rutting to over 2 in. UC Davis design charts for subbase thicknesses use 1-in. rutting as the failure criteria.

The comprehensive UC Davis study began with a literature review that found little domestic research and a paucity from overseas. The study then load tested some local existing PICP projects with an 18,000-lb truck axle to better understand deflection under it and the pavement strength. The deflection data was used to estimate the stiffness (elastic modulus) of each pavement layer by conducting computer-based mechanistic analysis modeling that correlates modeled and measured stresses, surface deflections, and permanent strains (rutting) to pavement layer strengths. This data was also used to determine subbase thicknesses for full-scale testing at a 96-ft long PICP test track over which the HVS could run truck tires and loads.

PICP Test Track Drawing

The PICP cross sections tested at UC Davis with the HVS machine.

The test track included three subbase thicknesses (approximately 18 in. or 450 mm, 27 in. or 650 mm and 37 in. or 950 mm) instrumented to provide data on stresses while loaded and rutting (see diagram below). The weak clay soil subgrade was compacted and non-woven geotextile was placed on the subgrade and sides of the excavation. Above the subbases was a 4-in. (100 mm) thick layer of ASTM No. 57 aggregate, 2 in. (50 mm) of No. 8 aggregate, 3 1/8-in. (80 mm) thick concrete pavers and permeable jointing aggregate. A concrete curb restrained the No. 57 aggregate, bedding and pavers. The figure below shows a cross section of the test track. The aggregates were granite quarried from the foothills of the Sierra Nevada Mountains.

The testing represents the first full-scale load testing on PICP in the western hemisphere and one of a few studies globally that examines the structural response of open-graded bases to wheel loads. The UC Davis design charts go to one million ESALs, the maximum loads also provided on the 2011 ICPI design chart. The revised charts will appear in an emerging ASCE national standard on PICP as well as in an updated edition of the ICPI PICP manual. Both are scheduled for release in 2016.

The project was funded by the ICPI Foundation for Education and Research, the Concrete Masonry Association of California and Nevada, the California Nevada Cement Association and the Interlocking Concrete Pavement Institute.