Analysis And Study On Silting Of Permeable Asphalt Pavement

In 2013,General Secretary Xi Jinping put forward a request to build a "sponge city" at the Central Urbanization Conference.That is,the water in the city can be stored and moved in time like water in a sponge by seepage,storage,drainage,and use,and can also be used when needed.As a new generation of urban stormwater management concepts,sponge cities can effectively alleviate environmental problems such as urban waterlogging and heat island effects.To build a sponge city,first of all,it is necessary to effectively curb urban rainwater and runoff pollution.It is an important part to transform impervious pavements into permeable pavements.Permeable pavement uses a large amount of coarse aggregate and a small amount of fine aggregate to achieve the purpose of a large void structure inside the pavement,so that surface runoff can penetrate downward along the void inside the pavement,thereby promoting natural water circulation and reducing floods.In addition to the water-permeable function,water-permeable roads also have the advantages of reducing noise pollution,reducing road surface temperature,reducing the probability of vehicle accidents,and improving fuel efficiency.However,with the use of the pavement,the gaps on the pavement will be gradually blocked by pavement damage,traffic leakage,road surface sediment,etc.,and the water permeable function will gradually decrease,and will become an impervious road at last.Therefore,the formation,detection,cleaning and protection of permeable pavement are the top priorities of research on permeable pavement.Solving the problem of blocking will make a huge contribution to the promotion of permeable pavement.At present,the focus of research at home and abroad is on the realization of the permeable function of permeable pavements,focusing on the research of high-viscosity modified asphalt and road performance,but less research on the problem of silting.This paper starts with the formation and detection of permeable pavement blockage,and studies the blockage problem of permeable pavement blocks in sponge cities.The main contents of the thesis are:(1)Based on the simulation of the permeable asphalt mixture using the particle flow software PFC to obtain its void characteristics,the vertical section of the test piece was simulated using a silica gel board to simulate the meso simulation of the indoor silting process.Observe the effects of silt,water flow and number of cycles on the silting situation,observe and analyze the characteristics of each stage of the silt process,the location and depth of the silt.(2)Through the silt simulation test of the indoor PAC Marshall test piece,explore the change of the test piece's weight,porosity,and water permeability coefficient during the silting process,and evaluate the changes in the water permeability of the road through these three indicators.(3)Through the tire drop test in the laboratory,verify the noise reduction performance of the permeable road.A ring-shaped simulated permeable pavement was built in the laboratory to investigate the change in noise reduction performance during the silting process.Based on the change of the road noise before and after the permeable pavement is blocked,a method for evaluating the degree of pavement blockage is proposed to achieve the purpose of non-destructive and accurate detection of the pavement blockage degree.The paper mainly simulates the silting problem of pervious asphalt pavement,explores the silting behavior model and proposes a method that can evaluate the degree of silting,which provides a reference for the actual detection,cleaning and protection of pervious asphalt pavement silting,and provides a reference for silting in sponge cities.The solution of the problem is of great significance.