中面层沥青混合料改性前后疲劳性能对比研究

The Comparison and Research on Fatigue Performance of Asphalt Mixtures Before and After Modification in Intermediate Layer

采用材料试验系统MTS810进行小梁应力疲劳试验,通过对中面层采用的级配AC-20、LAC-20和SAC-20沥青混合料改性前后的耐疲劳性能进行对比分析发现:除级配SAC混合料外,级配LAC和级配AC混合料改性后的抗疲劳性能均有提高,在相同应力比情况下,级配LAC混合料改性后其抗疲劳性能提高显著。在一定应力水平作用下,随着应力比的提高,载重量的增大,级配LAC混合料改性后的疲劳寿命增加的幅度逐渐减小,在较低应力比情况下,其抗疲劳性能明显增强。荷载应力水平不同,改性沥青混合料疲劳寿命提高的倍数不同,基本随着荷载应力水平的提高,疲劳寿命提高的倍数逐渐减小。

The trabecutae stress fatigue test of asphalt mixtures with gradation of AC--20, LAC--20 and SAC--20 are done by material testing system MTS810. It is found that the anti-fatigue properties of asphalt mixtures modified with gradation of LAC--20 and AC--20 are increased by comparative analysis of fatigue performance for asphalt mixtures before and after modification except SAC mixture, at the same stress ratio, the anti-fatigue properties of gradation LAC mix after being modified improves significantly. With the improvement of the stress ratio and the increase of loading capacity under certain stress level, the increasing amplitude of the fatigue life for gradation modified LAC--20 mix decreases gradually, and its anti-fatigue properties significantly enhances at a lower stress. Improvement multiples of fatigue life of modified asphalt mixture is different under different load stress levels. The fatigue life decreases gradually with the improvement of the load stress level.