Comparative Study Of Asphalt Pavement Design Methods Of China And Foreign Countries

With an increasing number of our country’s foreign project, the opportunity of our country’s highway enterprises to participate in international competition and exchange is also greatly increased. The differences of the design and construction of asphalt pavement between different countries will directly lead to differences of asphalt pavement using performance. Then we should have a comprehensive, accurate and clear grasp for the representative worldwide highway asphalt pavement design specification, and find out the deficiency existing in our country’s current specification, learn overseas advanced technology achievements to promote the technology level of highway enterprises of our country.(1) Comparative analysis of asphalt pavement structure design concept. Chinese and foreign pavement structure system and function, pavement structure combination and selection method are compared. The result showed that we should put forward more targeted styles of pavement structure combinations, according to the traffic characteristics and resource allocation situation in different areas. Especially in economically developed areas, the construction of permanent pavement structure should be considered.(2) Comparative analysis of asphalt pavement design method and indicators. As the pavement structure is different, the design indexes also exist certain differences. The process of cumulative damage of pavement structure in the action of load and environment is considered in US, and it is more accordance with the actual pavement behavior. The main design index of French is the tensile strain of asphalt layer bottom and compressive strain of top surface of soil base. The index of surfacing deflection and tensile stress in the bottom is adopted in our country.(3) The influence of different seasons on traffic axle load conversion and soil base resilience modulus and the influence of material dynamic parameters on the pavement structure design are studied. The pavement structure is designed with the season correction coefficient of axle load conversion, equivalent soil base resilience modulus replacing the worst season soil base resilience modulus, dynamic modulus of materials replacing static modulus.(4) The asphalt pavement are designed using different design software. Chinese and French pavement structures are analyzed using BISAR 3.0, and road surface deflection, subgrade surface compressive strain, tensile stress and compressive strain are calculated. At the same time, the rationality of the fatigue damage design index of asphalt layer is analyzed. The result showed that tensile stress index is not suitable for our country’s asphalt pavement design, tensile strain index should be used for asphalt pavement design.