Fatigue evolution characteristic and self-healing behaviour of asphalt binders

The self-healing ability of asphalt material has a significant effect on improving fatigue life of asphalt pavement. The objective of this paper was to investigate the stage characteristics of fatigue damage of asphalt binder and its associated self-healing behaviours. Firstly, the rheological behaviour and fracture surface morphology were discussed to investigate the fatigue evolution characteristics of asphalt binders. Secondly, an effective method for interpreting the self-healing capability of asphalt binder at different fatigue stages was proposed by conducting fatigue-healing-refatigue tests and Fourier transform infrared spectroscopy analysis. Finally, the effect of temperature on the self-healing properties of different aging asphalt binders at different fatigue damage stages was explored. The results show that the stage characteristics of fatigue damage of asphalt binders could be distinguished effectively by correlating complex shear modulus with ratio of dissipation energy change under load time history. The fatigue cracking morphologies of asphalt binders under cyclic shear loading are susceptible to the aging degree of asphalt binder. An index associated with initial dissipative energy and number of cycles could effectively evaluate the self-healing properties of different aging asphalt binders. After the occurrence of macrocracks, the mechanical properties of asphalt binder cannot be completely restored by increasing the temperature.