Reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) contain significant amounts of bitumen and their application in new constructions have been promoted as a sustainable practice in the pavement industry and to promote circular economy. However, this effort has faced challenges such as the aged bitumen’s inferior properties compared to the virgin counterpart and its unknown contribution to new pavements. To address the latter issue, liquid additives were used under the general title of rejuvenators. That poses an additional challenge associated with the lack of clear metrics to differentiate between softeners and rejuvenators. While revitalising aged asphalt binder to regain its desirable properties would be an ideal solution, progress in this area has been limited by a lack of understanding of rejuvenation mechanisms at the molecular level and the absence of representative test parameter(s) to evaluate both efficacy and durability of rejuvenators. In this study, both laboratory experiments and computer modelling were combined to not only compare efficacy of several rejuvenators, but also explain why some rejuvenators are effective while others are not. It was found that all studied rejuvenators have a softening effect on aged asphalt, but only a few of them revitalised aged asphalts’ physicochemical and rheological properties at the binder level. At the mixture level, a lower number of gyratory compaction and reduced rate of crack propagation were observed after the addition of high performing rejuvenators to the asphalt mixtures containing RAP. The reduction in crack propagation rate could be attributed to both enhanced blending between an aged and virgin bitumen and the revitalisation of aged bitumen properties. The latter phenomenon was explained at the molecular level based on the rejuvenator’s ability to interact with aged asphaltene molecules intercalating into and separating asphaltene nanoaggregates. Accordingly, this molecular-level phenomenon is reflected in two ways: an increase in crossover modulus and crossover frequency at the binder level, and a reduced crack propagation rate at the mixture level.

再生沥青路面 (RAP) 和再生沥青瓦 (RAS) 含有大量沥青，它们在新建筑中的应用已被推广为路面行业的可持续实践并促进循环经济。然而，这项工作面临着挑战，例如与原始沥青相比，老化沥青的性能较差，以及它对新路面的未知贡献。为了解决后一个问题，液体添加剂被使用在再生剂的总称下。这带来了一个额外的挑战，因为缺乏明确的指标来区分软化剂和再生剂。虽然振兴老化的沥青粘合剂以恢复其理想的性能将是一个理想的解决方案，由于缺乏对分子水平的再生机制的了解以及缺乏代表性的测试参数来评估再生剂的功效和耐用性，这一领域的进展受到限制。在这项研究中，实验室实验和计算机建模相结合，不仅比较了几种再生剂的功效，还解释了为什么一些再生剂有效而另一些无效。研究发现，所有研究过的再生剂都对老化沥青有软化作用，但只有少数能在粘合剂水平上恢复老化沥青的物理化学和流变性能。在混合料水平上，在向含有 RAP 的沥青混合料中添加高性能再生剂后，观察到回转压实次数减少和裂纹扩展速率降低。裂纹扩展速率的降低可归因于老化和原始沥青之间的混合增强以及老化沥青性能的恢复。后一种现象在分子水平上被解释为基于再生剂与老化的沥青质分子相互作用的能力，这些老化沥青质分子插入和分离沥青质纳米聚集体。因此，这种分子水平的现象反映在两个方面：粘合剂水平的交叉模量和交叉频率的增加，以及混合物水平的裂纹扩展速率降低。后一种现象在分子水平上被解释为基于再生剂与老化的沥青质分子相互作用的能力，这些老化沥青质分子插入和分离沥青质纳米聚集体。因此，这种分子水平的现象反映在两个方面：粘合剂水平的交叉模量和交叉频率的增加，以及混合物水平的裂纹扩展速率降低。后一种现象在分子水平上被解释为基于再生剂与老化的沥青质分子相互作用的能力，这些老化沥青质分子插入和分离沥青质纳米聚集体。因此，这种分子水平的现象反映在两个方面：粘合剂水平的交叉模量和交叉频率的增加，以及混合物水平的裂纹扩展速率降低。