Effect of Soy-Based Asphalt Rejuvenators on Asphalt Binders of Different Performance Grades

The objective of this study was to evaluate the effect of three soy-based biorejuvenators and one conventional petroleum-based oil on aged asphalt binders. Two neat asphalt binders (PG 64-22 and PG 70-16) were aged in a rolling thin-film oven (RTFO) and in a pressurized aging vessel (PAV). Different proportions of rejuvenating agents (RA) were added to the aged binders, and the rheological properties were measured. Rejuvenation effectiveness was also assessed through Fourier Transform Infrared spectra and a reduction of the chemical aging indices. The overall results indicated that the soy-based bio-oils were able to restore the rheological and chemical properties of aged asphalt. The optimum content of the bio-oils that resulted was relatively lower than that obtained for the petroleum-based oil, which can be explained by the lower viscosity of these biomaterials. The Fourier transform infrared analysis indicated that both the petroleum-based oil and the bio-oils were able to rejuvenate the aged binders by restoring the chemical aging indices, at least partially, to the condition of the virgin binder, with the bio-oils performing better than the petroleum-based rejuvenator.