Research on the fatigue whole life of asphalt mixture based on the nonlinear damage theory

Abstract

The analytical solution of the fatigue crack forming life based on the nonlinear cumulative damage model was deduced by using the simply supported beam with mid-span loads as the study model. Then the fatigue whole life model by the Paris formula with the crack length factor was established. Flexural-tensile strength test and fatigue test were made by using the trabecular specimen at different temperatures. By the contrast of the asphalt mixture fatigue life at different temperatures and stress ratios, it was found that as increasing of temperature, the fatigue life of the trabecular specimen will reduce. When it is at the same temperature, the fatigue life will reduce as the stress ratio increasing. The fatigue developing life of the asphalt pavement will occupy a higher ratio of the whole fatigue life when the temperature is higher. The fatigue developing life is shorter when the temperature is lower. The values of the fatigue damage parameter a∗ and p were obtained by the regression of the test data. The expressions of the functional relation between a∗ and p with temperature T were deduced. The change law between the crack developing speed and the stress intensity factor amplitude was studied to determine the parameters A and n in the formula Paris under different stress ratio. The established model in this paper was verified effectively by contrast of the calculation values of the fatigue whole life model and the test values.