The Numbers Tell the Story
There are just over 100 companies with 170 plants manufacturing concrete unit paving in the U.S. and Canada. Unit paving products (defined in Master Format Section 32 14 00) include interlocking concrete pavers and permeable interlocking concrete pavers that conform to ASTM C 936 Standard Specification for Solid Concrete Interlocking Paving Units or CSA A231.2 Precast Concrete Pavers, the U.S. and Canadian product standards. Unit paving also includes paving slabs and grid units. Interestingly, there has been a paving slab standard in Canada since 1972, CSA A231.1 Precast Concrete Paving Slabs, but no concrete grid product standard there.
Conversely, there is no ASTM paving slab standard for U.S. markets yet, but there is a grid standard, ASTM C1319 Standard Specification for Concrete Grid Paving Units. The reason there is no grid product standard in Canada is that the product isn’t specified much there. Regarding an ASTM standard for paving slabs, the good news is that an ASTM committee recently balloted a draft standard for commercial paving slab applications (typically pedestrian and roof plaza decks). The committee is working through revisions and re-balloting for possible approval later this year.
Like many construction product standards, most designers don’t memorize the requirements for ASTM and CSA paver and slab product standards. ICPI certifies that paving products have met applicable ASTM and CSA standards. ICPI producer members with current certifications can be found at www.icpi.org.
Each year, ICPI conducts a survey of unit paving manufacturers in the U.S. and Canada called the ”Industry Sales Profile.” The results from 2012 sales were recently received and provide some interesting numbers that suggest certain trends. The final report is for sale at www.icpi.org.
Here are some telling numbers: Paving slabs are seeing significant growth as well as pavers used in permeable applications to reduce stormwater runoff. The 2011 survey indicated just over 16 percent of all sales came from paving slabs. The 2012 survey indicates 34 percent. This speaks to a continuing trend toward larger units, especially in commercial and residential pedestrian applications.
Another interesting statistic is the increase in the portion of paving units for permeable pavement applications. These have consistently risen each year in spite of the recent Great Recession. The increase from 2011 to 2012 was 2.8 percent to 4.8 percent based on survey responses from the U.S and Canada. Since most permeable paving units conform to ASTM C936 or CSA A231.1, the portion of permeable paving units sold of all units conforming to these standards is around 8.3 percent in 2012, with 75 percent going to commercial and municipal uses. Grouping together pavers and slabs, this portion represents one-sixth to one-fifth of all the concrete paving units sold to commercial and municipal markets. The numbers are telling us a story about the growing acceptance of PICP.
In this issue, we explore the growth in permeable applications with intriguing case studies from Lancaster, PA, and Nashville, TN. The Nashville project replaced dysfunctional porous asphalt with concrete pavers, and Lancaster discovered substantial savings in the processing of combined sanitary and storm flows by developing a green infrastructure plan that includes permeable pavement. The proof is in the numbers: When selecting pavement for green infrastructure projects that provides the best performance, concrete unit paving is gaining recognition as the best choice.