Abstract
The projected growth in Australia's population will result in increased urbanisation leading to more impervious surfaces, and subsequent increased stormwater runoff and pollution. Water sensitive urban design (WSUD) has arisen in response to the need to address stormwater issues related to urban developments. Permeable pavements are one type of WSUDs designed to allow stormwater runoff to infiltrate through the pavement structure and eventually discharge, reducing peak stormwater runoff and also reducing pollution known to be attached to and transported by suspended sediments. The trapping of sediments is a critical part of the stormwater treatment process of permeable pavements. However, ironically it is also this process that causes clogging, reducing infiltration performance over the time. The processes governing clogging are still not well understood. Butareis known to be affected by the mass of the trapped sediments and the sediment particle size distributions (PSD). This study investigated whether the infiltration rates of permeable pavements are directly affected by the PSD of the sediments trapped. Testing was carried out using the double-ring infiltrometer test (DRIT). Results showed clogging was correlated with sediment containing generally smaller sized sediments. Variation found between infiltration rates and PSDs of sites showed that the smaller particle sizes had the most impact on infiltration, reducing rates by up to 34%. A number of other factors also substantially affected permeable pavement infiltration rates including construction techniques, maintenance history and underlying soil type.