Utilization of RAP in asphalt pavements may lead to severe quality problems, mostly due to asphalt aging phenomenon. Within the scope of this study, the use of rejuvenators to improve the properties of RAP is investigated. Two different types of waste oils together with a commercial rejuvenator are used. The rejuvenated bitumen samples are evaluated from both rheological and microstructural aspects. In addition, mixture testing also employed to investigate the effectiveness of used rejuvenators. Experimental studies on bitumen samples included conventional and Dynamic Shear Rheometer (DSR) testing and Atomic Force Microscopy (AFM) imagings. The results unveiled that, the utilization of rejuvenators can significantly improve the quality of recycled asphalt and threatened the aged bitumen quality. Missing bee-structures of aged bitumen samples evolve in a different type of surface topography while the mixtures performance evolves in terms of workability. The rejuvenation process provides viscous behavior to aged bitumen. The Rejuvenation Index (RI) which is a dimensionless value, simply evolves this fact. While the RI of the non-rejuvenated aged bitumen is taken as 1 (one) as per RI definition, the neat bitumen RI is calculated as 0.79, the RI of waste oils are calculated as 0.74 and 0.79 while the commercial sample RI is calculated as 0.60. Among the rejuvenators, waste oils showed similar results with almost same volume of peri- and para-phase since the commercial rejuvenator behaved more similar to neat bitumen. The rejuvenated samples workability performance improves using rejuvenating additives. Binder and mixture testing demonstrated high consistency and conformity with each other in terms of performance and aging characteristics. The results proved that, waste oils can be used as rejuvenating agents within RAP. Rejuvenators can significantly restore the properties of aged RAP bitumen and increase the amount of RAP in bituminous mixtures.

在沥青路面上使用RAP可能会导致严重的质量问题，主要是由于沥青老化现象。在本研究的范围内，研究了使用再生剂来改善RAP的性能。使用两种不同类型的废油以及商用再生剂。从流变学和微观结构两个方面评估了再生沥青样品。此外，还使用混合物测试来研究二手再生剂的有效性。沥青样品的实验研究包括常规和动态剪切流变仪（DSR）测试以及原子力显微镜（AFM）成像。结果表明，再生剂的使用可以显着提高再生沥青的质量，并威胁老化沥青的质量。老化的沥青样品中缺少的蜂结构会在不同类型的表面形貌中发展，而混合物的性能则在可加工性方面发展。复兴过程为老化的沥青提供了粘性行为。复兴指数（RI）是一个无量纲的值，可以简单地说明这一事实。根据RI定义，未再生的老化沥青的RI为1（一），而纯沥青RI为0.79，废油的RI为0.74和0.79，而商业样品RI为： 0.60。在再生剂中，废油在周相和对相体积几乎相同的情况下显示出相似的结果，因为商用再生剂的行为与纯沥青的行为更为相似。使用回春助剂可以提高回春样品的可加工性。粘合剂和混合物测试在性能和老化特性方面显示出很高的一致性和一致性。结果证明，废油可作为RAP中的再生剂。再生剂可以显着恢复老化的RAP沥青的性能，并增加沥青混合物中RAP的含量。