Reclamation of waste oils in asphalt modification towards enhanced low-temperature performance of pavement in cold region

To decrease the usage of petroleum asphalt and improve waste recovery, two different groups of recycled oils were selected to improve the low-temperature performance of asphalt binders in cold region. The multiple stress creeps recovery (MSCR) test, linear amplitude sweep (LAS) test and bending beam rheometer (BBR) test were performed to evaluate the rheological properties of recycled oil modified asphalt (ROMA). The thermal stress and double edge notched tension (DENT) tests were employed to characterise the low-temperature cracking resistance and ductile resistance of the ROMA, respectively. The results of this study showed that recycled oils significantly improved the low-temperature and fatigue performance of asphalt, which is manifested in a drop in the low-temperature critical cracking temperature of asphalt by 3°C, increase in crack tip opening displacement (CTOD) by 72.8%, and extension of fatigue life by 178.9%. The addition of recycled oils reduced the percentage of large molecule size (LMS) while increasing the percentage of medium molecule size (MMS) of the asphalt, which contributes to the better low-temperature performance of the ROMA. The results from this study provide insights into the reclamation of waste oils and developing the low-temperature modifier of asphalt pavements in cold region.