Abstract
In view of the influence of asphalt mixture nonlinearity on the mechanical response of pavement structure, the creep compliance of AC-16 under 0.1, 0.3, 0.5, 0.7 and 0.9 MPa is studied first. The results show that the asphalt mixture is in the linear viscoelastic region, when the load is in the 0.1-0.5 MPa interval. When the load is greater than 0.5 MPa, the creep compliance increases significantly, and asphalt mixture presents a nonlinear property. The Prony series is used to fit the creep compliance data, and the relaxation modulus is calculated based on the convolution relationship between creep compliance and relaxation modulus in viscoelastic mechanics. The relaxation modulus under different loads is introduced into the mechanical calculation of layered viscoelastic system. The calculation results show that the nonlinearity of asphalt mixture significantly affects the permanent deformation of asphalt layer, but has little effect on the fatigue problem of the asphalt base. In the design of pavement structure, attention should be paid to the nonlinearity of asphalt mixture.