Pervious concrete pavement addresses important environmental issues and supports green, sustainable growth by the use of pervious concrete, also known as porous, gap-graded, or enhanced porosity concrete. Porous concrete is concrete with reduced sand or fines, which permits rain and storm water runoff to drain through it rather than flood surrounding areas or storm drains. It is usually a mixture of 3/8” to 1/2” average diameter aggregate, hydraulic cement, other cementitious materials, admixtures and water. The use of pervious concrete is among the Best Management Practices (BMPs) recommended by the U.S. Environmental Protection Agency for the management of storm water runoff volume, rate, and pollutants.
In Pervious concrete, carefully controlled amounts of water and cementitious materials are used to create a paste that forms a thick coating around aggregate bedding layer, which provides storage and runoff treatment. A pervious concrete mixture contains little or no sand, creating a highly permeable, interconnected void content, which allows stormwater to flow through the concrete. When properly constructed, pervious concrete is durable, low maintenance, and has a low life cycle cost.
Where is Pervious Concrete being used?
- Pervious Concrete is being used for building pavements. Florida and other southeastern states have been installing them since the 1970s to control runoff, erosion, and flooding. Florida has been a leader in the construction of pavements using pervious concrete.
- Pervious concrete is being used for municipal stormwater management programs and private development applications, especially in California and Washington. The runoff volume and rate control, plus pollutant reductions, allow municipalities to improve the quality of stormwater discharges.
- Public and private developments have used pervious concrete, which is a naturally brighter surface than traditional asphalt, to reduce lighting needs and increase nighttime safety.
- Homeowners are using pervious concrete for driveways, walkways, pool decks and patios to eliminate puddling, prevent erosion, and save the expense of tying into local storm sewer systems.
Why is Pervious Concrete Better?
- We are all concerned about environmental issues like shrinking supply of good water, contamination of the aquifer, damage from storm water and pervious cement is an answer to all of that.
- Pervious cement requires less maintenance. It is more stable, thus it is far less apt to settle.
- Pervious Cement pavement technology creates more efficient land use by eliminating the need for stormwater retention and piping systems, which lowers overall project costs on a first-cost basis. Also it takes less time to install.
- It eliminates the need and associated cost of installing gutters.
- Research has shown that the light color of concrete is cooler than conventional asphalt and helps to reduce urban temperatures and improve air quality.
- Unlike the smoothed surface of conventional concrete, the surface texture of pervious concrete is slightly rougher, providing more traction to vehicles and pedestrians, increasing safety.