纤维沥青混凝土动力性能试验研究

采用变截面分离式Hopkinson压杆（Split Hopkinson Pressure Bar, SHPB），对普通沥青混凝土、玻璃纤维沥青混凝土、木质素纤维沥青混凝土和3个掺量的聚酯纤维沥青混凝土进行了3种应变率的冲击压缩试验研究.试验结果与分析表明，沥青混凝土具有应变率增强效应，其动力抗压强度及韧性指标随着应变率的增大而增大；但是，纤维沥青混凝土动力抗压强度及韧性指标增长率随应变率提高有递减趋势；纤维含量对沥青混凝土在动力条件下的动力行为有显著影响，聚酯纤维掺量为0.25%的沥青混凝土动力抗压强度及韧性指标最优；3种纤维都可以增加材料的动力抗压强度及韧性指标，聚酯纤维增强沥青混凝土抗压强度最佳，木质素纤维次之，玻璃纤维最差；聚酯纤维提高沥青混凝土韧性指标最佳，玻璃纤维次之，木质素纤维最差.

Experimental Study of the Dynamic Properties of Fiber Reinforced Asphalt Concrete

Compressive impact tests were conducted on asphalt concrete, glass fiber reinforced asphalt concrete, lignin fiber reinforced asphalt concrete and polyester fiber reinforced asphalt concrete of three contents with three strain rates using the split Hopkinson pressure bar with varying cross-sections. Test results and analyses have indicated that there is a strain rate enhancing effect on asphalt concrete. Both the dynamic compressive strength and the toughness index increase with the increase of strain rate. However, the increase rates of the strength and the toughness index decrease with the increase of strain rate of the fiber reinforced asphalt concrete. Fiber content has a significant influence on the dynamic behavior of asphalt concrete. At a polyester content of 0.25%, the compressive strength and the toughness index reach their maximal values. All the fibers can improve the dynamic properties of asphalt concrete. To improve compressive strength, polyester fiber is the best, lignin fiber the second, and glass fiber the last. And to improve toughness index, polyester fiber is the best, glass fiber the second, and lignin fiber the last.