ABSTRACT

The use of reclaimed asphalt pavement (RAP) is believed to contribute significantly towards overall energy conservation and environmental protection efforts. However, the recycling of aged binder from RAP requires a fundamental understanding of the interaction mechanism between such rejuvenators with recycled and unmodified binders. This study quantitatively investigated the impact of such agents in combination with the aging-rejuvenation process and other binder modifiers (SBS, crumb rubber, and a high viscosity modifier) on the fractional composition, rheology, and colloidal structural stability of asphalt binders. Based on these results, a rejuvenation index (RI) was proposed to quantitatively evaluate the rejuvenation of aged asphalt binder. Aging increased the proportion of resins and asphaltenes of asphalt binders which resulted in the decrease of its rheological properties. After the addition of the rejuvenators, the complex modulus of all aged binders were reduced. Certain rejuvenators transformed up to 5 percentage points of asphaltenes into other fractions. The aromatic oil-based rejuvenator showed the best rejuvenation of unmodified asphalt binder, but theRI was only 0.33. Overall, the results implied that rejuvenation of asphalt binders is a complex topic and further studies should be conducted to correlate the rheological behaviour with rejuvenation mechanisms beyond chemical fractions.

摘要

再生沥青路面 (RAP) 的使用被认为对整体节能和环境保护工作做出了重大贡献。然而，从 RAP 中回收老化粘合剂需要对此类再生剂与回收和未改性粘合剂之间的相互作用机制有基本的了解。本研究定量研究了此类试剂与老化再生过程和其他粘合剂改性剂（SBS、橡胶粉和高粘度改性剂）相结合对沥青粘合剂的分数组成、流变学和胶体结构稳定性的影响。基于这些结果，恢复活力指数 ( RI) 被提议定量评价老化沥青结合料的再生。老化增加了沥青结合料中树脂和沥青质的比例，导致其流变性能下降。添加再生剂后，所有老化粘合剂的复数模量均降低。某些再生剂将高达 5 个百分点的沥青质转化为其他馏分。芳烃油基再生剂对未改性沥青结合料的再生效果最好，但折射率仅为0.33。总的来说，结果表明沥青结合料的再生是一个复杂的课题，应该进行进一步的研究以将流变行为与化学组分以外的再生机制联系起来。