Rheological analysis of blended vs. recovered asphalt binders in rejuvenated mixtures with high reclaimed asphalt pavement

Abstract

Higher reclaimed asphalt pavement (RAP) in asphalt mixtures requires efficient rejuvenation. The efficiency of the rejuvenation can be evaluated by studying the rejuvenator, new and old binder blend. The blend must represent the binder blend inside the asphalt mixture to reflect reality. Extracting and recovering the binder of the rejuvenated asphalt mixtures containing RAP is the best practice to obtain the binder blend inside the asphalt mixture. 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 extracted and recovered (E&R) binder from RAP limits the extraction and recovery to the 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 represents the E&R binder from asphalt mixture concerning rheological performance and behavior properties. The rheological properties of three binder blends prepared under intense, moderate, and low blending conditions were compared with those of the E&R binder. Performance grade (PG), rutting potential (multiple stress creep and recovery test), fatigue resistance (linear amplitude sweep test) and behavioral characteristics (linearity and complex modulus tests) are the rheological properties of this study. It was found that intense and moderate blending conditions are good representatives of the E&R binder with regard to PG and PG+ designation. In addition, intense, moderate, and low blending conditions can be a surrogate for the PAV-aged E&R binder. It can be claimed that any intensity of blending conditions between intense and moderate lead to binder specimen that is almost identical to E&R binder with respect to rutting potential and characterization.