Research Of Clogging Behavior Of Double-layer Permeable Asphalt Pavement

Clogging problem is one of the main problems of permeable asphalt pavement,which seriously affects the popularization and application of permeable asphalt pavement.Double-layer permeable asphalt pavement is a unique form of pavement structure.The upper layer is thin and fine permeable asphalt mixture,and the lower layer is thick and coarse permeable asphalt mixture.With the aid of"sieve effect",the upper layer can effectively resist the large blockage to clog the voids,and the lower layer can store a large amount of rainwater,thus reducing surface runoff and delaying the peak time.Through indoor simulation clogging and cleaning tests,the clogging and cleaning cycles and cleaning effects of single-layer and double-layer permeable asphalt pavement are analyzed and compared.The main conclusions are as follows:(1)The permeability coefficients of Marshall specimens were measured by constant head permeameter.It was found that under the same void conditions of the upper layer and single-layer permeable asphalt mixture,double-layer permeable asphalt mixture had better permeability performance.(2)According to the indoor simulation clogging test,the clogging period of double-layer permeable asphalt pavement is 10.9 years,which is 1.6 times that of single-layer permeable asphalt pavement,and the cleaning period of double-layer permeable asphalt pavement is 7 years,which is 1.75 times that of single-layer permeable asphalt pavement.It shows that the double-layer permeable asphalt pavement has superior anti-clogging performance.(3)The influence of water pressure,washing time and clogging degree on cleaning effect is obtained through indoor simulation clogging cleaning test,and the characteristics that double-layer permeable asphalt pavement is easier to unclog blockage than single-layer permeable asphalt pavement are obtained.The research deepens the understanding of the double-layer permeable asphalt pavement,and the clogging and cleaning cycles can be used as reference for the actual cleaning and maintenance frequency of the permeable asphalt pavement;the cleaning capacity under different water pressures can be used as reference for the actual cleaning of the permeable asphalt pavement.