Influence of clogging on the effective life of permeable pavements

This paper investigates the 'effective life' (or useful lifespan) of permeable pavement installations subject to sediment loadings. The broad aims of this study, which included both laboratory and field work components, were to improve understanding of the long-term pavement hydraulic conductivity, to assess the effective life of permeable pavements and to quantify the degree of sediment trapping and associated pollutant retention. Three types of permeable pavement were investigated. For each type the effects of pavement cleaning were also investigated. Over a simulated 35 years of sediment loading conducted in the laboratory, the results showed reductions of 59-75% in hydraulic conductivity with an average sediment retention of 94%. Suspended sediment concentrations measured at the outflow of the laboratory test beds did not show any significant difference between pavers that were subjected to cleaning and those that were not. For the field studies presented in this paper, hydraulic conductivities were very high in locations where permeable pavements are subjected to small to moderate sediment loads. At other locations with high coarse sediment and organic sediment loads, hydraulic conductivity tests indicated that clogging occurred at a rapid rate, particularly where runoff. owing onto the pavement was concentrated.