Evaluation Of Purifying Layer Decontamination Effect Of Permeable Pavement

With the development of urbanization, impermeable pavement accounts for more and more proportion. However, negative effect of impermeable pavement becomes increasingly urgent, so many countries develop permeable pavement, in order to realize rainwater restoring and maintain urban water circulation. Road surface runoff, especially the early runoff, resulted from rainfall carries a great deal of organic contaminant, suspended substance and heavy metal, which certainly will pollute soil and groundwater if they are directly restored to the groundwater without any treatment, thereby exerting a negative influence on urban environment. Therefore, control and treatment of road surface runoff pollutants becomes an outstanding issue in the technology of permeable road surface.In order to meet the building requirements of road engineering, the solution of this thesis is to add a filter layer, that is, a "purifying layer", in a permeable road surface pavement structure, and to add materials with cleansing function and road service performance. First of all, on the premise that pollutants standard is determined, road runoff water sample is artificially deployed, homemade indoor laboratory equipments are prepared, the purifying performance of the chosen permeable pavement filter layer materials is tested and judged, the filter layer material with road service performance is selected, and the best pavement height of every kind of material for removing road runoff pollutants is determined.Then, the road runoff pollutants purifying effects of different permeable pavement combining forms are determined and analyzed, thereby determining a classical road surface structure of the permeable pavement road surface, on the base of controlling urban surface runoff pollution.This study has shown that the solution that adding "filter layer" material to permeable pavement structure has an obvious effect of reducing road surface runoff pollution concentration and avoiding groundwater from being polluted. This subject has important significance on developing road traffic system which meets requirements of the future environment protection.