玄武岩纤维沥青混合料的路用性能及抗裂性能

为研究玄武岩纤维对沥青混合料路用性能和断裂性能的影响，基于马歇尔试验确定了不同玄武岩纤维掺量下的最佳油石比，并基于此分析纤维掺量对路用性能、老化性能、抗断裂性能的影响规律及其改善效果。结果表明：（1）玄武岩纤维掺量将影响最佳沥青用量，需同时考虑纤维掺量以确定最佳油石比；（2）纤维质量掺量为0.1%时，具有最佳的改善效果，最大可将高温稳定性能、低温抗裂性能、水稳定性能分别提升31.5%~38.4%、24.4%~37.3%、1.2%~5.5%。纤维对老化沥青混合料的高温稳定性的改善程度最佳，尤其是动稳定度，改善程度是其他性能的1.28~15.0倍；其次是低温抗裂性；水稳定性的改善效果最弱。纤维可通过增加沥青混合料的延性，以提高峰值荷载对应的裂纹张开位移，且玄武岩纤维在中温情况下对沥青混合料的抗断裂性能改善效果要高于低温条件，最大可提升21.64%的断裂韧性。

Study on Pavement Performance and Fracture Resistance of Basalt Fiber Asphalt Mixture

To study the effect of basalt fiber on the pavement performance and fracture resistance of asphalt mixture, the optimum asphalt-aggregate ratio with the different basalt fiber dosages is determined by using the Marshall test. On this basis, the influence law of fiber dosage on pavement performance, aging performance and fracture resistance, and its improvement effect are analyzed. The results show that the dosage of basalt fiber will affect the optimal asphalt content, and the fiber dosage should be considered simultaneously to determine the optimal asphalt-aggregate ratio. When the fiber dosage is 0.1%, the optimal improvement effect is achieved, which can maximize the high-temperature stability, low-temperature fracture resistance and water stability to 31.5%~38.4%, 24.4%~37.3%, 1.2%~5.5% respectively. The improvement degree of the fiber on the high-temperature stability of aging asphalt mixture is the best, especially on the dynamic stability. The improvement degree is 1.28~15.0 times of the other performances, the low-temperature fracture resistance is better secondly and the improvement effect of water stability is the weakest. The fiber can improve the crack opening displacement corresponding to the peak load by increasing the ductility of asphalt mixture. And the improvement effect of basalt fiber on the fracture resistance of asphalt mixture at medium temperature is higher than that at low temperature. The maximum fracture toughness can be improved by 21.64%.