掺加纤维对高模量沥青混合料柔韧性及路用性能的影响

Study on the influence of fiber on flexibility and road performance of high modulus asphalt mixture

通过半圆针入度试验、直接拉伸试验和直接剪切试验研究了纤维对高模量沥青柔韧性和拉伸性能的影响,采用SEM分析了纤维增强布墩岩沥青(BRA)高模量沥青的表面形貌特征,并通过车辙试验、贯入剪切试验、低温弯曲试验评价了纤维高模量沥青混合料的高低温路用性能。结果表明:掺加单种纤维及复合纤维能显著提高BRA高模量沥青的蠕变柔量和抗拉强度;纤维的微观形貌差异决定了不同纤维对高模量沥青及其混合料的改性效果各有不同,采用复合纤维的方案可实现不同纤维对BRA改性沥青改性效果的叠加作用;复合纤维对改善高模量沥青混合料的抗疲劳耐久性效果良好。

The effects of fiber on the flexibility and tensile properties of high modulus asphalt were studied by semi-circular penetration test,direct tensile test and direct shear test. The surface shape of fiber BRA high modulus asphalt was analyzed by electron microscopy(SEM). The rutting test,penetration shear test,low temperature bending test were used to evaluate the high and low temperature road performance of the fiber high modulus asphalt mixture. The results show that the addition of single fiber and interwoven composite fiber can significantly improve the creep compliance and tensile strength of BRA high modulus asphalt. The difference in the microscopic morphology of the fibers determines that different fibers have different effects on the modification of high modulus asphalt and its mixture. The interwoven fiber blending scheme can achieve the superposition effect of different fibers on the improvement effect of BRA modified asphalt. It has a good effect on improving the fatigue durability of high modulus asphalt mixture.