Study On Macroscopic And Microscopic Deformation Of Asphalt Mixture At Different Temperatures Based On Discrete Element Method

Asphalt mixture is a kind of road material widely used in road engineering.Road asphalt pavement in use process,the different using conditions and changes in the external environment,prone to a variety of diseases,of which temperature is one of the main reasons influenced asphalt pavement diseases,because of the influence of high temperature and low temperature environment,prone to rutting of asphalt pavement,the phenomenon such as cracks,seriously affected the safety of road traffic and pavement service life.Therefore,it is particularly important to study the deformation characteristics of asphalt mixtures at different temperatures.In this paper,the evaluation method of asphalt mixture under high temperature and low temperature is analyzed.Rut test and low temperature bending failure test are selected as test methods to study the deformation of asphalt mixture under high temperature and low temperature.And discrete element numerical simulation is adopted to generate the model of asphalt mixture,based on the virtual model of asphalt mixture mesoscopic deformation and mechanical characteristics were analyzed,and finally obtained under the condition of macroscopic and mesoscopic deformation properties of mixture under different temperature,the asphalt mixture in the application of road engineering is of great significance.Specific research contents and achievements are as follows:(1)through the analysis of indoor rut test results under different high temperatures,the deformation characteristics of the mixture under different temperatures were obtained,and the internal relations of temperature,dynamic stability and cumulative rolling depth were obtained.(2)through bending failure test at low temperature,the average failure strain value of asphalt mixture at low temperature was obtained,and the low-temperature cracking resistance of asphalt mixture was evaluated with the critical bending strain energy index.(3)a virtual sample model of asphalt mixture is generated,which verifies the feasibility of discrete element method to simulate asphalt mixture.By means of force chain distribution,displacement distribution and stress distribution,the deformation and stress characteristics of asphalt mixture under micro conditions are obtained.