Study of fatigue performance of fiber reinforced high-viscosity asphalt mastic based on rheology

Open-graded asphalt mixture pavement, with its functional benefits of drainage and noise reduction, holds promising engineering application potential. The high-viscosity asphalt mastic significantly influences the performance of this open-graded asphalt mixture. In this study, the fatigue performance of fiber reinforced high-viscosity asphalt mastic was investigated based on rheology. Shear rheometer was used to perform temperature sweep tests, time sweep tests, and linear amplitude sweep tests on the fiber reinforced high-viscosity asphalt mastic. The influences of filler/binder ratio, filler properties, fiber type, and content on the fatigue performance of the mastic were analyzed. Time sweep test data was used to establish a prediction equation for temperature-stress fatigue life of the mastic. The interconnectivity and differences between various fatigue life indicators were studied based on phenomenology and energy dissipation theory. The fatigue characteristics and damage mechanism of the mastic were investigated using a viscoelastic damage model, and the fatigue lives at different strain levels were observed. The research results indicate that fatigue damage of high-viscosity asphalt mastic mainly occurs at low temperatures. An increase in filler/binder ratio at the same temperature reduces the anti-fatigue performance of the mastic. Compared with dust, mineral powder has a larger specific surface area and better fatigue resistance performance. The established temperature-stress equation can accurately predict the fatigue life of mastic under different temperatures and stresses. The fatigue indicators Np20 and Nfm, based on energy dissipation theory, show a favorable linear relation with the fatigue indicator Nf50 based on phenomenology, and these three indicators are consistent in evaluating the fatigue performance and life of the mastic. Np20 and Nfm are found to be more applicable for evaluating the fatigue performance of fiber reinforced high-viscosity asphalt mastic. The fatigue life of the mastic decreases with increasing strain levels, and high-viscosity asphalt mastic containing basalt fiber shows better adaptability to complex traffic conditions.