乳化沥青冷再生混合料和易性指标及影响因素

Workability Indicator for Emulsified Asphalt Recycled Mixture and Influence Factors

为了研究乳化沥青冷再生混合料和易性,采用自主研发的和易性测试设备,以扭矩值作为乳化沥青冷再生混合料和易性表征指标,研究了不同特性的乳化沥青、回收沥青路面材料(reclaimed asphalt pavement,RAP)掺量及拌和用水量对乳化沥青冷再生混合料和易性的影响规律,分析了乳化沥青冷再生混合料和易性影响因素的显著性,并通过反算水泥初凝时间以及旋转压实成型试件的体积参数是否在规范范围验证了测试方法及指标的合理性.结果表明:再生混合料和易性随着RAP掺量的增加而变差,合适的拌和用水量能显著改善再生混合料和易性;RAP掺量和拌和用水量对再生混合料和易性有显著影响,而乳化沥青特性的影响不明显;乳化沥青冷再生混合料在拌和后存在一个最佳压实时机,推荐扭矩阈值为20 N·m.

In order to study the workability of emulsified asphalt cold recycled mixture （ECRM）, thedifferent characteristics of emulsified asphalt, reclaimed asphalt pavement （RAP） content and theinfluence laws of mixing water content were researched with the self-developed workability testequipment. Moreover, the significance level of influence factors was analyzed by statistic methods.Finally, the rationality of this method and the indicator was verified by back-calculating the jelling timeand the volume parameter of superpave gyratory compactor （SGC） molding method. The result shows thatthe workability of ECRM become worse with increasing RAP content, which can be siginificantlyimproved by proper mixing water content. RAP content and mixing water content have a significantlyimpacts on the workability ,while the emulsified asphalt has no such effects. ECRM has the optimal timingof the compaction after mixing, when the torque threshold is recommended for 20 N.m.