Analysis and Application of Shear Stress in High Grade Asphalt Pavements in China

Traditional studies show that shear failure always occurs in high temperature in high grade asphalt pavement. In this case, perpetual deformation and shear displacement will be produced under loading so as to shear destroy. At present, shear destroy appears in some new forms in high grade asphalt pavement in China, and the main causes may be changed. So shear ability of pavement needs more research. The paper discusses the shear stress distribution regularities, the influencing factors and the evaluation methods in high grade pavement, based on the Linear Elastic Multi-layer Theory and using the pavement finite-element programs. Results show that the maximum shear stress appears in 0-3cm depth below the surface regardless of the material's characteristics and thickness in each layer. The major influencing factors on the shear stress are modulus, Poisson ratio in asphalt layer and modulus in base layer. For three-layer high grade asphalt pavement structures in China, it is necessary to check the shear strength resistance in wearing layer and mid-layer. When performing the check, the exact location must be found to calculate the maximum shear stress in each layer. In addition, this paper puts forward the determination and evaluation methods of shear strength based on foregoing study results.