Fatigue and Nonlinear Performance Characterization of Asphalt Mastics: A Combined Approach

Asphalt mastics, composed of a bitumen matrix and fillers, play a vital role in the fatigue failure of asphalt mixtures. However, the mechanisms by which fillers influence the fatigue properties of asphalt mastics have not been thoroughly investigated. Moreover, fatigue failure in bituminous materials is often accompanied by pronounced nonlinear behavior, yet the relationship between fatigue performance and nonlinearity remains unclear. In this study, a novel approach for characterizing the nonlinear properties of asphalt mastics was developed by integrating Fourier transform rheology and Lissajous curve analysis with the linear amplitude sweep (LAS) test. Two categories of fillers—traditional mineral fillers and solid waste fillers—were selected to systematically examine their effects on the fatigue property of asphalt mastics. The study further established a unified relationship between the fatigue and nonlinear properties of asphalt mastics, incorporating a toughness parameter. The results indicate that the LAS test, combined with advanced rheological analysis, enables accurate characterization of the nonlinear behavior of asphalt mastics. The influence of fillers on fatigue property is governed by the competing effects of negative physical hardening and positive particle-filling enhancement. Although the addition of fillers generally reduces the fatigue life of asphalt mastics, it simultaneously enhances their nonlinear characteristics. Notably, asphalt mastics containing solid waste fillers exhibit superior fatigue resistance and nonlinear performance compared to those with conventional mineral fillers. The unified expression relating fatigue life, nonlinearity, and toughness provides new insights into the design and performance evaluation of high-performance asphalt mastics. This research offers a significant reference for the development and optimization of durable and sustainable asphalt materials.