级配离析沥青混合料性能的试验研究

Influence Research of Gradation Segregation on Performance of Asphalt Mixture

通过室内试验,分析混合料级配离析状态和离析程度对沥青混合料体积参数、路用性能和力学性能的影响.结果表明,在不同离析程度下,粗集料离析对沥青混合料性能的影响大于细集料离析的影响.在粗集料集中区域,由于空隙率过大,吸水性和渗水性增大,对沥青混合料的水稳定性极为不利,还将大幅度降低沥青混合料的疲劳寿命和强度.在细集料集中区域,压实空隙率过小,虽然对沥青混合料的水稳定性和抗疲劳性能无不利影响,但将使沥青混合料的抗车辙能力和抗滑性显著降低.

Based on laboratory tests, an anlysis is made of the influence of state and degree of gradation segregation on volume parameter, service performance and mechanic performance of asphalt mixture. The study shows that the coarse aggregate segregation has a greater influence than fine aggregate segregation on the performance of asphalt mixture under the different levels of segregation. Coarseaggregate-rich regions is of high air voids and low asphalt contents which easily lead to moisture damage as well as to durability-related distress such as fatigue life and indirect tensile strength; On the other hand, mat areas rich in fine aggregate are associated with low voids and high asphalts. Although these areas have no obvious adverse effect on moisture susceptibility and fatigue life of asphalt mixes, they are susceptible to rutting and flushing.