Experimental Study on Performance of Bioasphalt Rejuvenated Asphalt Binder

To investigate the feasibility of using bioasphalt as a rejuvenator, castor oil-based bioasphalt was used as a rejuvenator to prepare bioasphalt rejuvenated asphalt.The effects of bioasphalt dosage on related properties of the rejuvenated asphalt binder, before and after rolling thin film oven(RTFO) aging, were investigated by laboratory tests. Results show that the penetration of the rejuvenated asphalt increases with the increment of the bioasphalt content, while the softening point decreases. In terms of penetration, the rejuvenated asphalt containing 30% bioasphalt is almost recovered to a similar level of original asphalt. However, the bioasphalt does not show desired effect on ductility. Additionally, the 135℃ viscosity, equivalent softening point, equivalent fracture point and retained penetration ratio of the rejuvenated asphalts decrease with the increase of the bioasphalt content, while the penetration index, plasticity temperature range, softening point increment and viscosity aging index increase. Namely, the bioasphalt shows a positive effect on the improvement of low temperature behavior and temperature susceptibility, while a negative effect is shown on high temperature behavior and aging resistance. Although, the aging resistance of bioasphalt rejuvenated asphalt is deteriorated with the increase of the bioasphalt content, it is still superior to that of the original asphalt when the content of bioasphal is bellow 30%.