Full-scale Loading Test And Numerical Simulation Analysis Of Powdered Rubber Asphalt Pavement

With the rapid development of the expressway network in Hebei Province,the road surface diseases such as cracks,rut and so on are also faced with many factors.Traditional asphalt pavement structure design requirements for modified asphalt pavement to a certain extent can not meet the actual demand.How to improve the pavement performance,prolong the service life of the pavement is imminent.In this paper,the demand of asphalt mixture materials for different surface layers of asphalt pavement is analyzed.The properties of rubber powder modified asphalt,SBS modified asphalt and matrix asphalt mixture with different surface layers were evaluated.The design of the full-scale loading test road test scheme is completed,and the monitoring data are analyzed.The dynamic responses of different structures,axle loads and speeds were analyzed by using finite element software.The main research work of this paper is as follows:1.By statistical analysis of typical expressway diseases in Hebei Province,the main types of asphalt pavement diseases are crack and rut.The evaluation indexes of cracking resistance of the upper layer,rutting resistance of the middle surface layer and fatigue resistance of the lower layer,as well as the evaluation methods of low temperature bending test of the upper layer,rutting test of the middle surface layer and four-point bending fatigue test of the lower layer are put forward.The demand of asphalt mixture with different surface layers is analyzed by using finite element software.2.Based on the evaluation method of performance of asphalt mixture of different surface layers proposed,mixed tests were carried out on different asphalt of upper,middle and lower surface layers respectively to obtain better performance of rubber powder modified asphalt mixture in all aspects.The dynamic stability and test temperature equations of rubber powder modified asphalt mixture and SBS modified asphalt mixture in the middle surface layer were summarized and analyzed,and the fatigue life equations of rubber powder modified asphalt mixture and matrix asphalt mixture in the lower layer were obtained.3.Establish the principle of sensor layout,analyze the embedding method of sensor in different positions,and determine the sensor layout position.In order to simulate the real natural environment of asphalt pavement,the loading scheme of test road under three different temperatures of low temperature,normal temperature and high temperature was designed.4.By analyzing the data collected by the sensor of the test road,it is obtained that the laminating stress under the asphalt pavement is 9.2% larger than that of the SBS asphalt pavement.It is suggested that the material with better bearing capacity should be selected for the base of the asphalt pavement.The vertical strain at the bottom of the middle layer of rubber powder asphalt pavement is 6.2% lower than that of the upper layer,and the rutting resistance is better.The finite element software is used to obtain that the tensile stress and shear stress of the asphalt powder pavement structure are reduced by 10% and 30% respectively compared with that of SBS pavement structure,which verifies the accuracy of the performance evaluation indexes of different asphalt pavement structure layers proposed in this paper.