Research On Rutting Prediction Of Asphalt Pavement Based On Shear Performance

The phenomenon of rutting has become the main form of disease of asphalt pavement in China.The appearance of rutting not only affects the comfort and safety of driving,but also reduces the service life of pavement With the deepening of research,road researchers at home and abroad have realized that simply improving the performance of materials can not solve the problem of rutting.It must be analyzed from the perspectives of structural mechanical behavior of asphalt pavement and mechanical properties of asphalt mixture.Therefore,how to effectively control and predict the rutting phenomenon of asphalt pavement has become an urgent problem in the current road field.This paper mainly studies from two aspects:theoretical analysis and laboratory test.Firstly,the finite element software is used to analyze the variation of shear stress in asphalt layer under different loads and different horizontal forces.It is considered that the existence of large shear stress near the wheel track is an important factor leading to shear flow deformation of rutting.Then,the prediction model of the permanent deformation of asphalt mixture layer proposed in the specification and the determination method of each parameter are analyzed.Two typical semi-rigid base asphalt pavements are selected for rutting estimation at different temperatures.From the estimation results,Temperature has a greater impact on the production of ruts.The total-thick burger rutting test was carried out by using the Hamburg Rutting Tester,and the rutting test results were verified to the rationality of the prediction results.By comparison,it was found that both of them showed two stages of rapid deformation and stable deformation.Three kinds of asphalt mixture were selected for torsional shear test.The test results show that the torsional shear strength of AC-13 is the highest under the same test conditions,AC-20 was next,and AC-25 was the smallest Based on the results of torsional shear test and rutting test,the regression analysis method shows that the torsional shear strength and the rut depth show a good power function relationship.There are some differences between rutting prediction and actual rutting prediction,based on the permanent deformation prediction model,this paper fully considers the shear stress of the pavement and the high temperature shear resistance index of the asphalt mixture to correct the permanent deformation model.Finally,the prediction model was validated by the test results of Hamburg rutting at different temperatures,the results show that the model can better reflect the permanent deformation of asphalt mixture.