废机油改性乳化沥青冷再生混合料疲劳性能

Fatigue performance of cold recycled emulsified asphalt mixture modified by waste engine oil

为改善冷再生沥青混合料(cold recycled asphalt mixture,CRAM)的耐久性能,提出将废机油改性乳化沥青应用于CRAM。在探究废机油改性乳化沥青冷再生混合料(waste engine oil modified cold recycled emulsified asphalt mixture,WEO-CRAM)力学性能和路用性能的基础上,采用间接拉伸疲劳试验研究了WEO-CRAM的疲劳寿命,并应用Weibull分布对疲劳试验结果进行分析,建立了疲劳方程。结果表明:CRAM冷再生沥青混合料的劈裂强度随废机油掺量的增加逐渐增加,不同再生沥青路面(recycled asphalt pavement,RAP)掺量的混合料均对应一个最佳废机油再生剂掺量。与普通CRAM相比,WEO-CRAM的抗裂性能至少提高了13%,且废机油对混合料的高温性能和水稳定性影响不大。基于Weibull分布建立的疲劳方程可以有效地评估WEO-CRAM的疲劳寿命。在不同应力比下,WEO-CRAM具有良好的抗应力变化敏感性和抗疲劳破坏能力,在应力比为0.45时的疲劳寿命较CRAM提高了35%。

In order to improve the durability of cold recycled asphalt mixture(CRAM),waste oil modified emulsified asphalt was applied to CRAM.Based on the exploration of the mechanical properties and road performance of waste engine oil modified cold recycled emulsified asphalt mixture(WEO-CRAM),the fatigue life of WEO-CRAM was studied by indirect tensile fatigue test.The fatigue test results were analyzed by Weibull distribution,and the fatigue equation was established.The results show that the splitting strength of CRAM increases with the increase of the content of waste engine oil,and each of the mixture with different recycled asphalt pavement(RAP)content corresponds to a specific optimal content of waste engine oil regenerant.Compared with ordinary CRAM,the cracking resistance of WEO-CRAM is improved by at least 13%,and the waste engine oil has little effect on the high temperature performance and water stability of the mixture.The fatigue equation based on Weibull distribution can effectively evaluate the fatigue life of WEO-CRAM.Under different stress ratios,WEO-CRAM has good sensitivity to stress changes and fatigue failure resistance.The fatigue life at a stress ratio of 0.45 is 35%higher than that of CRAM.