A Comprehensive Evaluation of Damping, Vibration, and Dynamic Modulus in Reclaimed Asphalt Pavement: The Role of Rejuvenators, Polymer, Temperature, and Aging

Reclaimed asphalt pavement (RAP) is increasingly essential in pavement engineering to enhance environmental sustainability. The use of rejuvenators and polymers has solved concerns about the dynamic performance of RAP; however, its damping and vibration properties still need to be investigated. Pavement vibrations pose a threat to public health, impeding sustainability. This research investigates RAP's damping performance, resonant frequency, and dynamic modulus using a non-destructive impact resonance (IR) test. Three RAP percentages (0%, 50%, and 100%), three waste oil rejuvenators (paraffin oil, fatty acid, and base bitumen), and recycled high-density polyethylene (r-HDPE) were employed. Rejuvenators and r-HDPE were used separately and simultaneously at varying percentages. Evaluations were conducted under two conditions (long-term aged (LTA) and unaged) and two temperatures (25 °C and -12 °C). Findings reveal a performance hierarchy: under unaged conditions, rejuvenators exhibit superior efficacy, while simultaneous application of rejuvenator and recycled polymer optimally performs in prolonged aging scenarios. Statistical analyses underscore the pivotal role of rejuvenator quantity, irrespective of recycled polymer presence, aging, and temperature, as determinants in sculpting RAP's damping performance, resonant frequency, and dynamic modulus.