Novel Methods for Adding Rejuvenators in Asphalt Mixtures with High Recycled Binder Ratios

Abstract

Most asphalt mixtures being placed in the United States currently use RAP as not only a sustainable method of building pavement surfaces but also an economical one. The stiffness and brittleness of the aged RAP binder, which negatively affects mixture performance in high quantities, can be mitigated using rejuvenators. The current method of rejuvenator incorporation does not consider RAP pretreatment for potentially enhancing RAP binder activation. In this study, the degree of dispersion of rejuvenator for RAP pretreatment was evaluated along with the effect of marination. The experimental plan included two bio-based rejuvenators, two high RAP mix designs, and three RAP pretreatment methods. The performance properties of high RAP mixtures prepared with different rejuvenator addition methods were assessed based on the DWT, Cantabro, IDEAL-CT, I-FIT, and DCT. Results suggested that asphalt contractors should continue to pre-blend rejuvenators into the virgin binder for best rejuvenating effectiveness and mixture performance.