Area-rated rational coefficients for Portland cement pervious concrete pavement

Surface area specific runoff coefficients were measured for nonclogged Portland cement pervious concrete systems according to the rational method. The systems were simulated with pervious concrete blocks with porosities ranging from 16 to 27% placed over sand subbases. Rainfall was simulated in a flume setup with surface slopes ranging from 2 to 10%. There was negligible runoff for typical rainfall events under 100 years frequency in South Carolina. Runoff rates were also simulated for a combination of direct rainfall and additional stormwater runoff from adjacent areas. The results obtained are important for the design of pervious concrete runoff management systems.