Pervious concrete

[1][2] It is an important application for sustainable construction and is one of many low impact development techniques used by builders to protect water quality.

Pervious concrete lowers the NRCS Runoff Curve Number or CN by retaining stormwater on site.

Pervious concrete also naturally filters storm water[6] and can reduce pollutant loads entering into streams, ponds, and rivers.

A pervious concrete pavement allows the transfer of both water and air to root systems to help trees flourish even in highly developed areas.

[10] A common flatwork form has riser strips on top such that the screed is 3/8-1/2 inches (9 to 12 mm) above final pavement elevation.

[clarification needed] Slump and air content tests are not applicable to pervious concrete because of the unique composition.

The designer of a storm water management plan should ensure that the pervious concrete is functioning properly through visual observation of its drainage characteristics prior to opening of the facility.

[citation needed] Concerns over the resistance to the freeze-thaw cycle have limited the use of pervious concrete in cold weather environments.

[10] The addition of a small amount of fine aggregate to the mixture increases the durability of the pervious concrete.

[21] Related, having a well prepared 8 to 24 inch (200 to 600 mm) sub-base and a good drainage preventing water stagnation will reduce the possibility of freeze-thaw damage.

[21] Using permeable concrete for pavements can make them safer for pedestrians in the winter because water won't settle on the surface and freeze leading to dangerously icy conditions.