Study On Optimal Design Of Fully Permeable Asphalt Pavement For Urban Trunk Road

At present,urban waterlogging disaster is serious in China,and urban road drainage system cannot effectively solve the problem of hydrological cycle.Waterlogging has paralyzed urban traffic,and rainwater has accumulated on the surface for a long time,seriously affecting urban residents' travel.To this,the country puts forward "sponge city" concept.Among them,the permeable asphalt pavement,as urban permeable pavement,has good permeability and anti-skid performance,which can effectively improve the safety and visibility of driving in rainy days.At the same time,it can effectively reduce noise pollution and slow down the urban "heat island effect",which is an indispensable means of road technology application in "sponge city".In this paper,under the multi-index system,the pavement material parameter index verification,structural combination design and permeability performance verification of fully permeable asphalt pavement are studied.The main research contents are as follows:(1)Based on the research foundation at home and abroad,four kinds of asphalt mixture types are used as research objects.The surface layer adopts OGFC-13 and PAC-13.ATPB-25 and LSPM-25 are used for flexible base.The optimum whet-to-stone ratio of OGFC-13(4.4%),PAC-13(4.2%),ATPB-25(3.0%)and LSPM-25(3.2%)was determined by designing the mixing ratio of four kinds of permeable mixtures.(2)Under the multi-index system,the material design parameters are verified.The high temperature stability,water stability and anti-fatigue performance of pervious asphalt mixture were evaluated by laboratory test.The applicability and limitations of each parameter to permeable asphalt mixture are analyzed.(3)The structural combination optimization design of full permeable asphalt pavement is carried out.Considering the traffic load condition and rainfall condition,the thickness of each layer of pavement structure is designed.The structural scheme was verified from the aspects of bearing capacity and permeability,among which,the research results of domestic scholars are used as the verification index.Finally,a scheme to optimize the structure of permeable asphalt pavement is proposed.