Effect of bottleneck-causing clogging on infiltration-runoff of pervious concrete pavement system

A pervious concrete pavement system (PCPS) is susceptible to clogging. In this study, a laboratory study was performed to measure the effects of clogging on the infiltration-runoff process by monitoring the water contents at four vertical locations in PCPSs with varying clogging degrees, exposed to different rainfall intensities. The measurements show that clogging tends to cause an infiltration bottleneck (located between 5 and 15 cm from the PCPS surface), which is the major contributor to the earlier occurrence of runoff. Moreover, bottleneck-causing clogging can change the runoff pattern from stored-full runoff to infiltration excess runoff. After this change, the water storage capacity of the PCPS cannot be fully utilised, and the beneficial effect of the PCPS on hydrology declines greatly. The results obtained are important for improving the understanding of clogging of the entire PCPS, which can help design better PCPSs and develop reasonable maintenance strategies.