不同压实方法对乳化沥青冷再生混合料疲劳性能的影响研究

Study on Influence of Different Compaction Methods on Fatigue Performance of Emulsified Asphalt Cold Recycled Mixture

摘要:

不同压实成型方法制备的乳化沥青冷再生混合料的疲劳性能存在较大差异，通过采用改进的马歇尔击实法和垂直振动压实法制备两种乳化沥青冷再生混合料，进一步对乳化沥青冷再生混合料进行间接拉伸疲劳试验，在试验结果基础上建立基于Weibull分布的间接拉伸疲劳方程，对不同压实成型方法的疲劳方程参数进行分析研究，探索不同压实成型方法对乳化沥青冷再生混合料疲劳性能的影响。试验结果表明， 垂直振动压实法制备乳化沥青冷再生混合料的平均力学强度可达到现场取芯试件的92%，而改进的马歇尔击实成型试件的平均力学强度仅为现场取芯的65%；与改进的马歇尔击实法相比，垂直振动压实法的最佳乳化沥青掺量和外掺水量分别降低了9%和11%，同时抗水损害性能、低温抗裂性能和高温抗车辙性能可分别提高4%、12%和35%；基于Weibull分布建立的疲劳方程可有效评价乳化沥青冷再生混合料的疲劳寿命，垂直振动压实法制备的乳化沥青冷再生混合料表现出良好的应力变化敏感性和疲劳耐久性，其在应力比为0.5时的疲劳寿命是改进马歇尔击实法的1.36倍。

Abstract:

The fatigue performance of cold recycled emulsified asphalt mixture (CEAM) prepared by the different compaction methods is quite different. The improved Marshall compaction method and vertical vibration molding method are used to prepare two kinds of CEAM, and the indirect tensile fatigue test of CEAM is further carried out. On the basis of the test results, the indirect tensile fatigue equation based on Weibull distribution is established. The fatigue equation parameters of the different compaction forming methods are analyzed to explore the influence of the different compaction forming methods on the fatigue performance of CEAM. The test results show that the average mechanical strength of CEAM prepared by the vertical vibration compaction method can reach 92% of that of in-situ coring specimen, while the average mechanical strength of the improved Marshall compaction forming specimen is only 65% of that of in-situ coring specimen. Compared with the improved Marshall compaction forming method, the optimum emulsified asphalt content and water content of the vertical vibration molding method are decreased by 9% and 11% respectively, and the water damage resistance, low temperature crack resistance and high temperature rutting resistance are increased by 4%, 12% and 35% respectively. The fatigue equation established based on Weibull distribution can effectively evaluate the fatigue life of CEAM. The CEAM prepared by vertical vibration molding method shows the good stress change sensitivity and fatigue durability, and its fatigue life at the stress ratio of 0.5 is 1.36 times that of the improved Marshall compaction forming method.