Ecological Effect Evaluation Method of Permeable Slow-Traffic System

Most of concrete constructions built on urban ground surface are impermeable materials, which are very bad for urban ecosystem. This paper studied evaluation methods of permeable slow-traffic system though its drainage effect, noise reduction effect and thermal island effect reduction. The results show: as for drainage effect, permeability coefficient increase with asphalt mixture void ratio; non-fines concrete combined with graded gravel penetrates the most quickly, followed by graded gravel base and cement stabilized macadam combined with graded gravel. For noise reduction effect, the acoustical absorptivity of permeable concrete increase with the void ratio rising. And for thermal island effect reduction, temperature difference between surface and middle course of permeable pavement is much larger than that of other types of pavement structures, which illustrates that permeable pavement can alleviate thermal island effect positively. The results suggest that drainage effect, noise reduction effect and heat island effect reduction can be used to evaluate permeable slow-traffic system reasonably.