RESEARCH ON Temperature FATIGUE DAMAGE AND CRACKING IN ASPHALT LAYER OF RIGID-Flexible Composite Pavement

The theories of damage mechanics, heat transfer and fracture mechanics, and finite element method (FEM) were used to analyze the characteristics of temperature fatigue damage, fatigue life and crack propagation of asphalt layer. The results show that temperature fatigue damage is concentrated in the surface of asphalt layer, and the damage value in the surface of asphalt layer increases linearly with the increase of temperature changes. The damage value in the surface of asphalt layer increases continuously with the increase of modulus of asphalt layer and amplitude of temperature change. The level tensile stress in the surface of asphalt layer decreases linearly with the increase of temperature changes. The fatigue life of asphalt layer decreases continuously with the increase of amplitude of temperature change. The minimum critical thickness of asphalt layer is 4cm based on high temperature effects.Tthe increasing of thickness and the decreasing of modulus of asphalt layer can play a role of slowing temperature crack propagation. The results are of significance in rational design and application of rigid-flexible composite pavement.