Numerical Simulation Of Mechanical Behavior Of Asphalt-aggregate Interface

In recent years,with the quick construction and development of roads in our country,bituminous pavement has rapidly become the main form of roads across the country with its outstanding advantages of flat surface,low noise and short construction period.However,due to the huge land area of our country,the great disparities of climatic and geographical conditions in different regions as well as the large traffic volume and the phenomenon of serious overload,in the face of the above problems,the bituminous pavement is prone to suffer many common problems such as pit,rut,pill up,thus affecting the normal use of the road.In recent years,the performance of asphalt mixture has become a hot spot in the relevant research,and the asphalt-aggregate interface enjoys a top priority in the hot issues.In the research,The asphalt in the interface of the asphalt-aggregate interface exists in the form of asphalt membrane,and the performance of asphalt membrane exerts an important influence on the mechanical properties of the asphalt-aggregate system.Therefore,the study on the influence of the performance of asphalt membrane on the mechanical properties of the interface is of great help to improve the understanding of the mechanism failure of the interface between asphalt and aggregate,and is of great significance to improve the performance of bituminous pavement and reduce the road damage.In order to study the mechanical properties of the asphalt aggregate interface,this paper first carries out the forming and shear tests of the specimens among aggregate,asphalt and aggregate,and then obtains the forming load,the thickness of asphalt membrane as well as relevant test results,so as to prepare for the later finite element simulation.This paper proposes an improved structural asphalt layer model and introduces the application of cohesion model in the finite element software.Based on cohesion model,ABAQUS software is used to simulate the interface shear test of asphalt aggregate,and the influence of the thickness and strength of asphalt layer on the simulation results is emphatically analyzed.By comparing the results of the finite element simulation with the test results,the author has found that the finite element model involved the structural asphalt layer can more accurately reflect the test results and overcome the shortcomings of the conventional model.At the same time,the author points out that the main factor affecting the shear strength of the asphalt layer in the shear process is the yield stress of the asphalt layer rather than the thickness of the layer.Considering the influence of fracture strain and fracture energy,the author has found that the fracture strain and fracture energy have great influence on the simulation results without taking the stickiness of the materials into consideration.