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Permeable Pavements


What is Permeable Interlocking Concrete Pavement?

Permeable interlocking concrete pavement (PICP) is comprised of a layer of concrete pavers separated by joints filled with small stones. Water enters joints between solid concrete pavers and flows through an "open-graded" base, i.e. crushed stone layers with no small or fine particles. The void spaces among the crushed stones store water and infiltrate it back into the soil subgrade. The stones in the joints provide 100% surface permeability and the base filters stormwater and reduces pollutants.
 


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PICP vs. Pervious Concrete vs. Porous Asphalt

Permeable Interlocking Concrete Pavement- is comprised of a layer of durable concrete pavers separated by joints filled with small stones.

Pervious Concrete- Pervious concrete is made from carefully controlled amounts of water and cementitious materials used to create a paste that forms a thick coating around aggregate particles. Unlike conventional concrete, the mixture contains little or no sand, creating a substantial void content between 15% to 25%.

Porous Asphalt- or "open-graded," asphalt pavement contains no fine aggregate particles thereby creating void spaces in the pavement. This allows water to collect within and drain through the pavement.

View the PICP comparison chart


Sustainability and PICP

 

Permeable Interlocking Concrete Pavement (PICP) can meet the LEED credit requirements under Sustainable Sites. These requirements limit site disruption and water pollution by managing stormwater. The pavements can reduce runoff-generating impervious cover and decrease the rate and quantity of runoff. PICP meets these credits through the filtering action of the base that reduces total suspended solids and phosphorous in runoff, as well as other pollutants.


PICP can also meet the sustainable sites requirement to reduce urban heat islands (thermal difference between urban and rural areas), minimize impacts on microclimates and in wildlife habitats. This is accomplished through increased albedo (a measure of the solar energy reflected from a surface) or use of a pavement system with less than 50% imperviousness. PICP has substantially higher reflectivity than conventional asphalt pavement and can meet the requirement for less than 50% imperviousness.


PICPs are eligible for LEED® credits under the U.S. and Canadian Green Building Councils (USGBC and CaGBC) guidelines. PICP typically meets the requirements for Conservation of Material and Resources, Recycled Content under the USGBC LEED for new construction where at least 20% of the building products should be manufactured within a radius of 500 miles (800 km) of the project. Most paving units are locally manufactured and delivered to projects within 500 miles (800 km). To find the closest manufacturer or distributor visit the ICPI Find A Member section. For additional information on U.S. or Canadian LEED credits visit www.usgbc.org or www.cagbc.org. 

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