Runoff-rainfall relationship for multilayer infiltration systems under artificial rainfalls

Three available porous pavement systems were studied to evaluate their infiltration capabilities of precipitation. Experiments were conducted to simulate different kinds of porous pavements with different sub-base materials in each of catchments, and the discharge volumes from each cell were monitored. The relationship between rainfall intensity, outflow and outflow duration was analyzed. Physical models were established in the laboratory. Results showed that all treatments of the porous pavements increased infiltration and decreased runoff. In all treatments, the optimum thickness of the porous pavement was 31-cm, which consisted of a 6-cm top layer of porous concrete and a 25-cm sub-base (10-cm concrete without sand and 15-cm aggregate base). Under a rainfall rate of 59.36 mm/h, the runoff coefficient of treatment B is 0 while the coefficient of the impervious pavement is 0.85.