How is pervious concrete produced?
Unlike conventional concrete, pervious concrete mixes contain limited or no fine aggregates, producing concrete with approximately 20 percent voids. Those spaces allow water to flow through the pavement, then a bed of uniformly sized aggregate below, and into the soil—reducing or eliminating stormwater runoff. Average strengths of pervious concrete are from 500 to 4,000 psi, but can go higher depending on the application; percolation rates average from 288 to 770 inches per hour. Dan Huffman, managing director of national resources for the National Ready Mixed Concrete Association, says pervious concrete is gaining ground fast. “The U.S. Environmental Protection Agency recommends pervious concrete as a Best Management Practice with compliance with federal stormwater law, and that’s a very powerful thing to say,” he says. “We should be using greywater water all over the place; we waste so much water and we just don’t have to,” he argues.
