玄武岩纤维对老化沥青混合料路用性能的影响

为研究玄武岩纤维对老化沥青混合料路用性能的影响,通过车辙试验、低温弯曲小梁试验、浸水马歇尔试验和冻融劈裂试验研究了玄武岩纤维对沥青混合料抗老化性能的作用。试验结果表明:虽然玄武岩纤维沥青混合料的动稳定度随老化时间增加,但相对于普通沥青混合料而言,其增加的幅度减缓,提出采用相对变形率作为老化性能评价指标;玄武岩纤维延缓了沥青混合料老化性能的衰变,使得老化后的混合料低温抗裂性改善;经短期老化和长期老化后玄武岩纤维沥青混合料水稳定性能均优于普通沥青混合料,且玄武岩纤维显著降低了长期老化试件的未冻融劈裂强度,因此在应用中应适当增加碾压次数。

Effect of Basalt Fiber on the Road Performance of Aged Asphalt Mixture

In order to reveal the influence of basalt fibers on road performance of aged asphalt mixtures, the rei-nforcing effect of basalt fibers in asphalt concrete during aging was investigated through some tests, which included high temperature rutting test, low temperature bending test, immersion Marshall test and freezing-thaw splitting test. The results show that, the high temperature property of basalt fiber mixture increases with aging time, but it tends to increase slower than the general asphalt mixture, and the relative deformation rate as the evaluation index of aging property is put forward; basalt fiber can delay the changes of asphalt aging properties, which reveals that low-tempe-rature cracking resistance for aged asphalt mixtures can be improved with basalt fibers; the water stability performance of basalt fiber asphalt mixture is better than general asphalt mixture after the short-term and long-term aging, and the basalt fiber will significantly reduce freeze-thaw splitting strength of specimen after long-term aging. Therefore, increasing the numbers of rolling appropriately must be considered in project.