The Influence of a New Food Waste Bio-Oil (FWBO) Rejuvenating Agent on Cracking Susceptibility of Aged Binder and RAP

This research aims to deliver a new promising asphalt binder rejuvenator developed from food waste to mitigate the effects of aging on the asphalt. The research relied on three different binders: two unmodified PG 64–22 binders and a Polymer Modified (PMA) PG 76–22 binder. Moreover, a field-extracted RAP binder is utilized in evaluating the rejuvenator’s efficiency. For this study, the proposed food waste bio-oil (FWBO) is compared against two market-available rejuvenators. The experimental program relied on aging control binder samples for each asphalt type with no rejuvenation using the Rolling Thin Film Oven (RTFO) test, followed by the Pressure Aging Vessel (PAV) test for 20 hours to create an Artificial RAP (ARAP) binder. Then, ARAP and RAP binders were blended with 5% by their weight with one of the two on-market rejuvenators (#1, #2) or the proposed FWBO rejuvenator. Testing results reveal that low-temperature relaxation was significantly improved for all the investigated samples after an additional PAV aging cycle, as Delta Tc values increased compared to the control binders. Further, samples’ master curves were used to calculate the Glover–Rowe (G-R) parameter, crossover frequency, and modulus (ωc, Gc*). The results clearly showed the ability of the FWBO to reduce the aging rate and improve the rheological properties of RAP binders. Further, the Fourier Transform Infrared Spectroscopy (FTIR) test showed that the new FWBO rejuvenator reduces the oxidation levels of the aged RAP binders, as suggested by the carbonyl index.