Review and prospect of four-point bending fatigue test of asphalt mixture

Fatigue cracking is one of the principal failure modes of asphalt pavement. The chief factors affecting the fatigue failure of asphalt pavement are load, environment, pavement structure and the fatigue resistance of asphalt mixture itself. Among them, the most important part is the research on the fatigue resistance of asphalt mixture, which has been studied deeply at home and abroad. This paper summarized some important research results and fatigue characterization parameters of the four-point bending fatigue test method in recent years, and suggested the future research direction of the four-point bending test. In the analysis and comparison of loading modes of four-point bending test, further research on various analysis methods is required. Researchers can appropriately refine the test method to account for nonlinear viscoelastic energy dissipation, as well as plastic and permanent deformation per cycle. The fatigue evaluation index of asphalt mixture can be comprehensively evaluated by four indicators, and can be combined with new fatigue characterization parameters in the future. It is suggested to develop a complete set of four-point bending fatigue test methods under various stress states consistent with the service state of asphalt pavement. This method can be used to eliminate the influences of environment, test condition and specimen size on the fatigue test results of asphalt mixture to improve the effectiveness and completeness of asphalt mixture fatigue performance characterization.