竹纤维沥青混合料的疲劳性能与其作用机理研究

Study on Fatigue Performance and Action Mechanism of Bamboo Fiber Asphalt Mixture

为研究竹纤维沥青混合料的疲劳性能和纤维增强机理,采用四点小梁弯曲疲劳试验测试竹纤维沥青混合料的疲劳寿命,并与木质素纤维沥青混合料进行对比分析。采用扫描电子显微镜(SEM)从微观角度揭示纤维增强沥青混合料疲劳性能的作用机理。结果表明:在相同的应力水平下,竹纤维沥青混合料的疲劳寿命与木质素纤维相当,其抵抗疲劳重复荷载的能力略优于木质素纤维,但其疲劳寿命对应力水平变化的敏感程度略高于木质素纤维。竹纤维对沥青混合料初始疲劳损伤的阻滞作用和对沥青混合料自愈能力的增强作用使其具有优良的改善混合料疲劳性能的效果。未来可进一步提高其表面粗糙度与其在混合料中的分散性以增强其对沥青混合料抗疲劳性能的作用效果。

In order to study the fatigue performance and fiber reinforcement mechanism of bamboo fiber asphalt mixture,four-point trabecular bending fatigue test was used to evaluate the fatigue life of bamboo fiber asphalt mixture,and the fatigue performance of the bamboo fiber asphalt mixture was compared with one of the lignin fiber asphalt mixture.In addition,the scanning electron microscope was used to reveal the mechanism of fatigue performance of fiber-reinforced asphalt mixture from a microscopic perspective.The results show that under the same stress level,the fatigue life of the bamboo fiber asphalt mixture is equivalent to that of lignin fiber,and its ability to resist repeated fatigue load is slightly better than that of lignin fiber,but its fatigue life is slightly more sensitive to the change of stress level than lignin fiber.The retardion effect of bamboo fiber on the initial fatigue damage of asphalt mixture and the enhancement of self-healing ability of asphalt mixture make it have an excellent effect of improving the fatigue performance of the mixture.In the future,the surface roughness of bambaoo fiber and its dispersibility in the mixture can be further improved to enhance its effect on the fatigue resistance of the asphalt mixture.