Fatigue-Healing Performance Evaluation of Fiber-Modified Asphalt Mixture

Fiber-modified asphalt mixture has been the focus in functional pavement materials because of its excellent mechanical and self-healing performance. In this paper, an indirect tensile fatigue test was conducted to study the fatigue-healing performance of fiber-modified asphalt mixtures under different fatigue damage degrees and influencing factors, and the optimal timing of healing was determined based on the degree of fatigue damage. According to the results, due to the rough surface and microwave-absorbing ability of fibers, fiber-modified asphalt mixtures exhibit significantly higher fatigue-healing performance than plain asphalt mixtures. Under the given experimental conditions, the fatigue life of fiber-modified asphalt mixtures can up to three times higher than ordinary asphalt mixtures. Although the enhancement effect of fibers on the fatigue-healing performance of the mixture decreases with the increasing fatigue test repetitions, when the healing timing is 10% of fatigue damage, the fatigue life of the fiber-modified asphalt mixtures after five repetitions is almost equivalent to its initial fatigue life. According to a comprehensive evaluation of the fatigue-healing performance of two fiber-modified asphalt mixtures, asphalt mixture with steel wool additive is considered to be a more suitable material for self-healing pavement applications.