Research On Structure And Material Of Asphalt Pavement Overlay On City Special Sections

Through the road pavement condition survey and capacity evaluation of four intersections of S120 ShiPai-Bridge, the paper analyzes the primary causes of breakages and puts forward different treatment measures accordingly.The object of this paper is to analyze the influence of load characteristics and different structural layer on composite pavement by ABAQUS, a calculation of finite element procedure. There are three main results:First, the best thickness of asphalt overlay is 18cm which is very close to the result of AASHTO and Effective Thickness Method in the United States. Because the maximum shear of different thickness surface always occurs in the intermediate part of asphalt overlay, the increase of middle asphalt overlay modulus can reduce the maximum shear effectively. Second, heavy-load transportation has great influence on pavement structure. Therefore it's necessary to do the stress analysis. All of these results may provide some useful experience and reference to the cement concrete pavement rebuilding in the future.The long hot summer, abundant precipitation throughout the year and heavy traffic condition, coupled with the effect of heavy canalization transportation, the frequent starts and breaks of the vehicles, and low traffic speed result in the deteriorating of the asphalt pavement such as rutting, upheaval and waveness at road intersection in Dongguan. The performance of the whole road has been seriously affected. Based on the asphalt pavement rutting formation mechanism and influencing factors, two methods of the aggregate gradation and the mixed anti-rutting agent are selected to enhancing Asphalt Mixture high temperature rut resistance.First, on the basis of analyzing the advantages and disadvantages of graded types of gradation, using the theory of gradation design to design five recommended specifications within the scope of gradation curve. Then having the Marshall test, rutting test on five gradation curve separately and find the most optimal gradation curve.Second, in order to fully understand the effect of anti-rutting agent on asphalt mixture, PR, duroflex, domestic RK300 three different kinds of anti-rutting agent is selected for experimental study on road performance and comparison with common asphalt. The experimental results showed that all the three anti-rutting agents can obviously improved the high temperature stability of the asphalt mixture. Meanwhile, it can enhance other performances of the asphalt mixture, such as water stability etc. Combining economy analysis, RK300 anti-rutting agent is the optimal performance. With high temperature of 70℃rutting test, the result showed that the addition of anti-rutting agent can improve the high temperature stability effectively.