厂拌热再生混合料回收沥青老化特性对新沥青诱导老化的研究  

Research on aging characteristics of recycled asphalt and its induced aging of new asphalt from hot in-plant recycled asphalt mixture

作　　者：李强 LI Qiang(Chongqing Wuzhen Corporation Limited,Chongqing 400041,P.R.China)

机构地区：[1]重庆巫镇高速公路有限公司,重庆400041

出　　处：《重庆大学学报》2023年第8期112-119,共8页Journal of Chongqing University

基　　金：国家自然科学基金资助项目(51708072)。

摘　　要：为探究厂拌热再生沥青混合料中新旧沥青的老化进程及老化机理,模拟再生混合料的拌和与使用过程,首先测试了基质沥青、回收沥青以及新旧沥青三种试样依次经历旋转薄膜烘箱老化试验RTFOT和加速加压老化试验PAV之后各自的动力粘度与路用性能,对比分析了热再生中新旧沥青在老化过程中的宏观性能衰减规律,进而采用红外光谱和差示量热分析扫描等微观测试手段探明了新旧沥青的老化进程与老化机理。测试结果表明,先后经历RTFOT老化和PAV老化之后,回收沥青的粘度上升最显著,低温性能下降也十分迅速,但新旧沥青的动力粘度与低温性能变化幅度均远远高于基质沥青,证明其老化速率较基质沥青快;新旧沥青在经历RTFOT老化和PAV老化过程中,除新沥青和回收沥青各自独立的老化外,还存在一种介于二者之间的化学作用,即回收沥青中某些活性基团对新沥青的老化进程具有较明显的促进作用,称之为“诱导老化”,这种诱导老化通过改变基质沥青的老化进程而改变其老化机理。In order to explore the aging process and mechanism of new asphalt in plant hot-mixed recycled asphalt mixture,the dynamic viscosity and partial road performance of the recycled asphalt,the mixture of new and old asphalt and the matrix asphalt after RTFOT aging and PAV aging were tested.The macroscopic performance attenuation law of the mixture of new and old asphalt during the aging process in thermal regeneration was compared and analyzed.After that,the aging process and mechanism of the mixture of new and old asphalt were explored by infrared spectroscopy and differential calorimetric analysis scanning.The results show that RTFOT aging and PAV aging make the viscosity of recycled asphalt rise significantly and the low temperature performance decline rapidly.After RTFOT aging and PAV aging,the change range of dynamic viscosity and low-temperature performance of the mixture of new and old asphalt is much higher than that of the matrix asphalt,which proves that the aging rate is faster than that of matrix asphalt.Meanwhile,microscopic analysis show that in addition to the independent aging of new asphalt and recycled asphalt,there is also a chemical effect between them,that is,some active groups in recycled asphalt have a more obvious promotion effect on the aging process of new asphalt,here called induced“aging”.This induced aging changes the aging mechanism of the matrix asphalt by changing the aging process of it.

关 键 词：热再生混合料 回收沥青 诱导老化 老化特性 老化机理 

分 类 号：U414.6[交通运输工程—道路与铁道工程]