Research On High Temperature Performance Of Composite Rubber Powder Modified Asphalt Mixture Under Aging And Freezing-thawing Conditions

In recent years,with the rapid development of our country’s automobile industry,the generation of waste tires has brought a relatively negative impact on the environment.The emergence of the more economical rubber powder modified asphalt mixture not only improves the road performance of the asphalt pavement,but also can effectively solve these "black pollution".However,due to the single modification effect of the rubber powder,rubber powder modified asphalt pavement has highlighted its shortcomings.SBS modified asphalt mixture has excellent road performance,but its cost is high,and its application is limited.At the same time,the asphalt pavement under high temperature environment is easy to be affected by the long-term effect of vehicle load.Permanent deformation occurs,and then rutting disease that affects driving comfort and safety occurs,which seriously reduces the service life of the road surface.Therefore,in response to the above problems,combined with the hotter climate in Inner Mongolia in summer and the road environment where snow melting salt is often used for snow melting on road ice and snow in winter,in this paper,through the triaxial repeated creep test and rutting test at different temperatures,the composite rubber powder modified asphalt mixture(prepared by superimposing the base asphalt with two modifiers of rubber powder and SBS)and SBS modified asphalt are studied.The high temperature performance of the mixture under the influence of long-term aging and freeze-thaw cycles.First,the creep deformation curves of the composite rubber powder modified asphalt mixture and SBS modified asphalt mixture obtained by the triaxial repeated creep test are used to obtain the creep deformation rate b of the two asphalt mixtures through analysis and calculation,and then use the center The normalization method normalizes the temperature,long-term aging,the number of freeze-thaw cycles,and the creep deformation rate b under the salt environment.Finally,the gray correlation analysis method is used to obtain the degree of influence of various factors on the high-temperature performance of the two asphalt mixtures.The results show that the four factors that affect the high temperature performance of the composite rubber powder modified asphalt mixture and SBS modified asphalt mixture are temperature> salt solution concentration> long-term aging> freeze-thaw cycles.Secondly,using the creep deformation curves of the composite rubber powder modified asphalt mixture and SBS modified asphalt mixture obtained by the triaxial repeated creep test to analyze the influence of different factors on the high temperature deformation of the two asphalt mixtures,using The four-unit five-parameter viscoelastic mechanics model fits the creep curves of composite rubber powder modified asphalt mixture and SBS modified asphalt mixture under various factors to obtain high-temperature viscoelastic parameters,and then analyze the high-temperature stability of the two asphalt mixtures from the perspective of viscoelasticity.The results found that the high temperature deformation of the composite rubber powder modified asphalt mixture is less than the high temperature deformation of the SBS modified asphalt mixture under any factors,indicating the high temperature deformation resistance of the composite rubber powder modified asphalt mixture Stronger.Finally,the rutting test results of composite rubber powder modified asphalt mixture and SBS modified asphalt mixture under different temperature conditions are analyzed.At the same time,the creep deformation obtained by the triaxial repeated test and the dynamic stability obtained by the rutting test are analyzed.Correlation analysis between DS and rutting depth DR.The results show that the high-temperature anti-rutting ability of the two asphalt mixtures decreases with the increase of temperature,and the high-temperature antirutting ability of the composite rubber powder modified asphalt mixture is better than that of the SBS modified asphalt mixture;there is a good correlation between the results of the triaxial repeated creep test and the rutting test,and it also verifies that it is reasonable to use the creep deformation obtained from the triaxial repeated test to evaluate the hightemperature performance of the asphalt mixture.