Optimization and validation of waste bio-oil based high-performance rejuvenator for rejuvenating aged bitumen

In order to efficiently utilize the waste bituminous pavement materials and waste bio-oil, the composition of bio-oil rejuvenator was optimized. The rejuvenation efficiency of the waste bio-oil rejuvenator was evaluated from rheological properties and chemical composition. In addition, a quantitatively evaluation index for the rejuvenation efficiency was proposed. The results show that the central composite design and response surface methodology is effective in optimizing composition of rejuvenators. The dosage of waste bio-oil in the rejuvenated bitumen reached 9%. Compared to another two commercial rejuvenators, waste bio-oil rejuvenator rejuvenated the aged bitumen more effectively. Its rejuvenation efficiency for rheological parameters of aged bitumen was close to 100%. The waste bio-oil rejuvenator restored the performance of aged bitumen by reducing the proportion of macromolecular substances. The rejuvenation efficiency of aromatics, colloidal instability index and carbonyl functional groups were 57.1%, 126.9% and 78.7% respectively.