Analysis Of Influencing Factors On Mechanical Properties Of Asphalt Mixture Based On Morphological Characteristic Parameters Of Coarse Aggregate

Asphalt mixture is mainly composed of asphalt binder and mineral aggregate,in which aggregate plays an important role in the performance of asphalt mixture.In this paper,in order to study the correlation between the morphological characteristics of coarse aggregate and the performance of asphalt mixture,the morphological characteristic parameters such as area,axial length,perimeter,axial coefficient,roundness,fractal dimension,convexity,roughness and angularity of coarse aggregate are obtained by using IPP image processing software,and the average morphological characteristic parameters and normal distribution expectation ? of coarse aggregate in different gradation are calculated.The Marshall index,compressive performance index,anti-splitting performance index and creep characteristics of different graded asphalt mixtures are obtained by using Marshall test,different temperature compression test,different temperature splitting test and uniaxial compression creep test at room temperature and high temperature.The temperature sensitivity of compressive strength,splitting strength and viscoelastic parameters of different gradation asphalt mixtures are calculated by power exponential function,double logarithmic coordinates,Burgers model,modified Burgers model,CAM model and Huet model.The influence of gradation on the performance of asphalt mixture is analyzed.The Pearson linear correlation coefficients between coarse aggregate shape characteristic parameters and asphalt mixture Marshall index,compressive performance index,anti-splitting performance index and viscoelastic index are calculated by using SPSS statistical analysis software.The grey correlation degree algorithm is used to calculate the grey correlation degree between the expected value of normal distribution ? of coarse aggregate morphological characteristic parameters and asphalt mixture Marshall index,compressive performance index,anti-splitting performance index and viscoelastic index.The results show that the Marshall index,tensile and compressive strength index and viscoelastic index of asphalt mixture are mainly affected by the axial coefficient,fractal dimension,roughness and corner parameters of coarse aggregate,but less affected by area,perimeter and axis length.