Effect of viscoelasticity on fatigue cracking of asphalt pavement

A viscoelastic 3-D finite element model was built to calculate the horizontal stresses in the surface and bottom layers of typical road asphalt pavement structure, and the effects of loading mode and temperature on their viscoelastic responses were analyzed. The results showed that the surface layer and the bottom layer of the road pavement experience the repeated horizontal tensile and compressive stresses under cyclic loading and small residual tensile and compressive stresses build up in the surface layer and bottom layer respectively. This is probably one of the factors causing top-down or bottom-up fatigue cracking in the asphalt pavement. The residual stresses, the compressive stress amplitude in the surface layer and the tensile stress complitude in the bottom layer of the asphalt pavement of the road all decline with rise of temperature.