纤维对厂拌热再生沥青混合料水稳定性影响研究

Research on the Effects of Fiber on Moisture Stability of Hot Central Plant Recycling Asphalt Mixture

再生沥青混合料的性能受原路面沥青混合料回收料(Reclaimed asphalt pavement,RAP)结团率、老化沥青性能变异性的影响,出现水稳定性不足的情况,影响再生沥青混合料的推广应用。然而,纤维可加强沥青与集料之间的联系,改善沥青混合料性能。因此,为研究纤维对再生沥青混合料性能的影响,本文以水稳定性为主要控制指标,通过室内试验讨论了聚酯纤维、玄武岩对不同RAP掺量的再生沥青混合料水稳定性的影响。结果表明:冻融后的再生沥青混合料的空隙率较冻融前增加3%~12%;再生沥青混合料劈裂抗拉强度与RAP掺量成正比,而再生沥青混合料劈裂抗拉强度随纤维掺量的增加呈先增大后减小的趋势;冻融劈裂抗拉强度比与RAP掺量成反比,与纤维掺量成正比,说明纤维可增强再生沥青混合料水稳定性。

The performance of the recycling asphalt mixture is affected by the agglomeration rate of the original road asphalt pavement(Reclaimed asphalt pavement,RAP) and the variability of the aging asphalt performance.The insufficient water stability will affect the popularization and application of the recycled asphalt mixture.However,fiber can strengthen the connection between asphalt and aggregate and improve the performance of asphalt mixture.Therefore,in order to study the effect of fiber on the performance of recycled asphalt mixture,water stability as the main control index,and the influence of polyester fiber and basalt on the water stability of recycled asphalt mixture with different RAP content is discussed through laboratory experiments.The results show that the void ratio of recycled asphalt mixture after freezing and thawing is increased by 3%~12% compared with that before freezing and thawing;the splitting tensile strength of recycled asphalt mixture is proportional to the content of RAP,while the splitting tensile strength of recycled asphalt mixture is proportional to the content of RAP.With the increase of fiber content,it first increases and then decreases.The freeze-thaw splitting tensile strength ratio is inversely proportional to the RAP content and directly proportional to the fiber content,indicating that the fiber can enhance the water stability of the recycled asphalt mixture.