This study aims to propose critical fatigue indicators for evaluating the restoration effectiveness of various rejuvenators on the fatigue performance of aged bitumen. The influence factors of rejuvenator type/dosage and aging degree of bitumen are involved, and different fatigue parameters from linear viscoelastic (LVE), linear amplitude sweep (LAS), and time sweep (TS) tests are analysed. The results reveal that bio-oil exhibits the greatest rejuvenation efficiency in improving fatigue life of aged bitumen, followed by engine-oil and naphthenic-oil rejuvenators, while aromatic-oil shows the lowest effect. Moreover, the rejuvenation percentages on fatigue parameters of rejuvenated bitumen enhance significantly with increased rejuvenator dosage but weaken as the aging level deepens. The fatigue failure temperature (FFT) from the LVE test, fatigue life (N_f5), peak strain (ɛ_sr), elastic modulus (E) from the LAS test, and crack width (C₅₀₀) from the TS test are recommended as critical indicators for fatigue performance evaluation of rejuvenated binders. Further, the crack width greatly correlates with other essential indicators and can be predicted using correlation equations without conducting the time-consuming time sweep test. The difference in these critical fatigue parameters of various rejuvenator-aged bitumen blends provides the macroscale basis for future nanoscale mechanism exploration and superior rejuvenator development.

本研究旨在提出关键疲劳指标，用于评估各种再生剂对老化沥青疲劳性能的恢复效果。涉及再生剂类型/用量和沥青老化程度的影响因素，分析了线性粘弹性（LVE）、线性振幅扫描（LAS）和时间扫描（TS）试验的不同疲劳参数。结果表明，生物油在提高老化沥青的疲劳寿命方面表现出最大的再生效率，其次是发动机油和环烷油再生剂，而芳香油的再生效率最低。此外，再生沥青疲劳参数的再生百分比随着再生剂用量的增加而显着增加，但随着老化程度的加深而减弱。LVE 测试的疲劳失效温度 (FFT)，_f5 )、峰值应变 (ɛ _sr )、LAS 测试的弹性模量 (E) 和TS 测试的裂缝宽度 (C _{500 ) 被推荐作为再生粘合剂疲劳性能评估的关键指标。}此外，裂缝宽度与其他重要指标有很大的相关性，可以使用相关方程进行预测，而无需进行耗时的时间扫描测试。各种再生剂老化沥青混合物的这些临界疲劳参数的差异为未来纳米级机理探索和优质再生剂开发提供了宏观基础。