Mechanical calculation method and analysis of asphalt pavement#br#
considering different modulus in tension and compression
Pan Qinxue1,2 Zheng Jianlong1,2
1. Key Laboratory of Road Structure and Material of the Ministry of Transport(Changsha), Changsha University of Science & Technology, Changsha
410114, China;2. School o f Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410004, China
Abstract：The current design theory of asphalt pavement is the traditional linear elastic theory, in which the compressive resilient modulus is used as the stiffness parameter of materials in the design without considering the different characteristics of road materials in tension and compression. Therefore, the bimodulus theory (i.e.the elastic theory with different modulus in tension and compression) was introduced into pavement mechanical analysis in this study. Based on the idea of iteration, the numerical calculation method of asphalt pavement structure with different modulus in tension and compression is established, and the subroutine was compiled by using secondary development platform UMAT of ABAQUS. Mechanical analysis of typical asphalt pavement structure was carried out, and the results show that the deviations in the calculation results of the mechanical response of critical points based on bimodulus theory and the traditional linear elastic theory are as high as 30%～50%, which deserves great attention. There are large tensile stress and tensile strain on the surface of asphalt pavement, which could be one of the causes of asphalt pavement damage. It is suggested to shift the design point of asphalt surface course from its bottom to the wheel gap region of pavement surface. The non-uniqueness of elastic modulus of road material can be effectively solved by applying bimodulus theory to the pavement structural analysis.
