Rheological Comparison Between Blended Asphalt Binders and Extracted and Recovered Asphalt Binder From Rejuvenated Asphalt Mixture With Very High Rap Content

Abstract

Efficient rejuvenation of the RAP’s binder facilitates the use of higher RAP contents. Assessing the efficiency requires evaluating the right blend of the rejuvenator, new and old binder that represents the real binder blend inside the asphalt mixture. Extracted and recovered (E&R) binder from the rejuvenated asphalt mixtures containing RAP is the best practice to obtain the existing blend of the rejuvenator, new and old binder. However, Extraction and recovery is not a common practice to study rejuvenation efficiency since it is time-consuming and energy-demanding with exposure to hazardous chemicals. Instead, blending rejuvenator, new binder and the E&R binder from RAP under appropriate blending conditions limits the extraction and recovery to RAP, and minimizes efforts for studying rejuvenation efficiency. This study aims to find the blending conditions under which the blend of the rejuvenator, new and RAP binder resembles the E&R binder from asphalt mixture rheologically. The rheological properties of three binder blends prepared under intense (IB), medium (MB) and low blending (LB) conditions were compared with those of the E&R binder. Performance grade (PG), rutting potential, fatigue resistance and behavioral characteristics are the rheological properties for making comparison. It was found that IB and MB are good representative of the E&R binder with regard to PG and PG + designation. In addition to IB and MB, LB can be a surrogate for the PAV-aged E&R binder. Also, any blending conditions between MB and IB for rutting potential and characterization are recommended.