Study On Road Performance And Acoustic Emission Characteristics Of High Viscosity Modified Pervious Asphalt Mixture

With the continuous progress of the construction of sponge city in China,the research on functional pavement has become a hot issue in the road construction industry.Ordinary dense-graded asphalt mixture pavement is limited by its own structure gap,weak drainage capacity,unable to drain the road area water in time,and adversely affecting the comfort and safety of driving,the proposal of permeable asphalt pavement can alleviate this situation to a greater extent,on the one hand,it ensures the safety of the vehicle's driving,on the other hand,timely replenishment of groundwater and mitigation of the urban heat island effect are worth further promotion and application.Due to the large gap of the permeable asphalt mixture,if the adhesion between the asphalt and the aggregate is insufficient,a large amount of early disease will occur on the permeable asphalt pavement,and the requirements for the use of the road cannot be met.Therefore,it is particularly important for the research on the high-viscosity asphalt.At the same time,acoustic emission technology as a dynamic non-destructive testing method,can collect the acoustic emission signal emitted by the internal structure of the material in the process of destruction,and analyze the characteristics of the acoustic emission parameters so as to achieve the prediction of the internal damage state of the material.At present,acoustic emission technology has been widely used in various production fields,but the application of it to asphalt mixture is rarely involved.Therefore,it is of important guiding significance to analyze the characteristics of acoustic emission parameters of asphalt mixture.This article relies on the key scientific research and development project of Jilin Province Science and Technology Department “Research and Application of Ecological Green Permeable Pavement Materials in Severe Cold Area” to study the surface layer material of permeable asphalt pavement,the effect of different modifiers on the viscosity-increasing performance of asphalt mortar was analyzed,and on the basis of this,the road performance test was conducted to discuss the improvement of various road performances of different modifiers on pervious asphalt mixture,finally,the acoustic emission characteristics of the permeable asphalt mixture during the compression test and the splitting test are studied based on the acoustic emission detection technology.The specific work carried out is as follows:(1)The rubber powder content of 8%~12% and the content of 6%~10% TPS tackifier were selected to be added to SBS modified asphalt,the variation of the penetration,softening point,ductility,elastic recovery and dynamic viscosity at 60°C of SBS modified asphalt with different additives were analyzed.Based on this,the optimal content of rubber powder and TPS tackifier was determined.(2)Formed permeable asphalt mixture test pieces,and the best oil-cement ratio of each type of permeable asphalt mixture was comprehensively determined by the leak test and dispersion test.On this basis,the road performance test of permeable asphalt mixture was conducted.The effects of the incorporation of rubber powder and TPS tackifiers on the road performance of permeable asphalt mixtures were discussed,and the correlation between voidage,interconnected voidage and permeability coefficient was discussed based on a self-developed permeability coefficient analyzer.The results show that the mixing of rubber powder and TPS tackifier can improve the pavement performance of pervious asphalt mixture,but the improvement degree of TPS tackifier to the performance of pervious asphalt mixture is better than that of rubber powder.In addition,the voidage and connectivity porosity of permeable asphalt mixture have a significant linear correlation with permeability coefficient.(3)The uniaxial compression tests of permeable asphalt mixtures were conducted at 20°C,40°C and 60°C,respectively,and the acoustic emission parameters of the permeable asphalt mixtures during the compression process were studied based on the acoustic emission technique.The splitting test of pervious asphalt mixture at-10 and 25 C was carried out respectively.Based on acoustic emission technology,the variation of acoustic emission parameters of asphalt mixture at different temperatures was discussed,and the feasibility of applying acoustic emission technology to pervious asphalt mixture was discussed.The results show that in the process of splitting and compression,the energy curve of the permeable asphalt mixture is in good agreement with the load curve,and the feasibility of applying acoustic emission technology to pervious asphalt mixture is verified.