Permanent Deformation Simulation And Rutting Depth Prediction Of Asphalt Pavement

Permanent deformation (rutting) of HMA is one of the major structural failures of flexible pavements. Significant rutting may influence the smoothness and roughness of asphalt pavements, and endanger the security of running cars. The increased rutting also causes severity diseases of the pavement surface. So predict the potential rutting level practically and reasonably is important in the design and management of the pavement. According to the methods of rutting prediction both at home and abroad, the permanent deformation value was simulated using finite element program ABAQUS. And a reasonable prediction method was given in this paper.At the beginning, the large scale circular track testing equipment of Chongqing Commnications Research and Design Institute was adopted to simulate real condition of asphalt pavement structure after high temperature. Three types of pavement structure included semi-rigid base and flexible base were produced and analyzed the inherent stress, strain and displacement of asphalt concrete, after about 500,000 repeated loads. Then formation mechanism of rutting and compare the existing methods.Secondly, the basic theory of finite element method was introduced. The emphasis was the creep model in ABAQUS and the possibility of using it analyzing asphalt mixture. According the interrelated data of the track testing, the material parameters of asphalt mixture were gained from creep test. A model of pavement by finite element software, ABAQUS, was built to simulate the permanent deformation of asphalt pavement, based on reasonable supposition and predigestion. The numerical results were compared with the track test and indicated that the approach was reliable.Considering the over loading of vehicles was very severity in our country, finite element method was used to simulate the asphalt pavement under heavy duty traffic. The purpose was to find the process of rutting forming and growing, especially the rutting of different structures under repeated loads of varies axles. With all research results above in the calculation, a method regarding rutting depth was developed. These provided some valuable theory for design of over loading pavement and prediction of rutting. Finally, integrated the research on pavement structure of test road,the equations were modified and compared with the results of track test in this study.