The utilization of Reclaimed Asphalt Pavement (RAP) in asphalt pavement has obtained global popularity because of its cost-efficiency, technical advantages, and positive environmental influence. However, incorporating RAP requires careful consideration of cracking resistance because of the existence of age hardening of bitumen in RAP. For the mixtures containing high RAP contents, rejuvenators are often applied to enhance the performances of aged bitumen and the cracking of mixtures. This research aims to evaluate the effects of different rejuvenators on the rheological properties of bitumen and the cracking resistance of the mixture under short and long-term aging conditions. To achieve this goal, three rejuvenators - namely, RA1 (petroleum-based), RA2 (waste vegetable oil-based), and RA3 (modified soybean oil-based) were evaluated at contents of 0%, 4%, 12%, and 20%, respectively. The dynamic shear rheometer (DSR) test results show that, under unaged and rolling thin-film oven (RTFO) aging conditions, blended bitumen with RA1 and RA3 have higher G*/sinδ than RA2. Conversely, under pressure aging vessel (PAV) aging conditions, blended bitumen with RA1 and RA3 has lower G*sinδ than that with RA2. Regarding the cracking resistance, the indirect tension asphalt cracking test results show that, under short-term oven aging (STOA) conditions, the mixture using RA2 and RA3 has a higher cracking tolerance index (CTIndex) than the one with RA1. However, under long-term oven aging (LTOA) conditions, the mixture using RA1 has the highest CTIndex value. In addition, the high correlations between G*sinδ with CTIndex and post-peak slope (|m75|) and between the CTIndex and |m75| are observed.

中文翻译：

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再生剂和老化条件对混合沥青性能及高RAP含量热沥青混合料开裂行为的影响

再生沥青路面（RAP）在沥青路面中的利用因其成本效益、技术优势和积极的环境影响而受到全球欢迎。然而，由于 RAP 中存在沥青时效硬化，因此掺入 RAP 需要仔细考虑抗裂性。对于RAP含量高的混合料，经常使用再生剂来增强老化沥青的性能和混合料的裂化性能。本研究旨在评估不同再生剂对沥青流变性能以及混合物在短期和长期老化条件下的抗裂性的影响。为了实现这一目标，对三种再生剂——RA1（石油基）、RA2（废植物油基）和RA3（改性大豆油基）进行了评估，其含量分别为0%、4%、12%和分别为20%。动态剪切流变仪（DSR）测试结果表明，在未老化和滚动薄膜烘箱（RTFO）老化条件下，RA1和RA3混合沥青比RA2具有更高的G*/sinδ。相反，在压力老化容器（PAV）老化条件下，RA1和RA3混合沥青的G*sinδ比RA2低。关于抗裂性，间接拉伸沥青开裂试验结果表明，在短期烘箱老化（STOA）条件下，使用RA2和RA3的混合料具有较高的抗裂指数（CT指数）比 RA1 的要好。然而，在长期烘箱老化（LTOA）条件下，使用RA1的混合物具有最高的CT指数价值。此外，G*sinδ 与 CT 之间的高度相关性指数和峰后坡度（|m75|) 和 CT 之间指数和|米75|被观察到。