Simulated Performance of In-Place Pervious Concrete under Varying Storms, Surface Areas, and Infiltration Rates

Computer model simulations were conducted of an existing parking lot with pervious concrete low-impact development (LID) controls using the U.S. EPA Storm Water Management Model (SWMM). For three different types of storms, simulations were performed using a range of pervious concrete pavement area coverages and infiltration rates to assess the effects of these variables on runoff volume. Field measurements of in-place pervious concrete infiltration rates averaged 45mm/h, suggesting that the pervious concrete was not performing as an effective LID control. The modeling results show that increasing the area of pervious concrete pavement coverage by 30% reduced the volume of runoff by 21-45%, depending on the intensity of the rainfall. However, the same volume of runoff could be reduced by maintaining the desired infiltration rate of the original coverage of pervious concrete pavement. Overall, results illustrate the effectiveness of maintaining high infiltration rates in well-constructed, small, pervious pavement areas in contrast with poorly maintained pervious pavement covering large areas. (C) 2018 American Society of Civil Engineers.