Chemical Composition and Rheological Characteristics of Binders Containing RAP and Rejuvenator

Abstract

One of the most important concerns in using different additives for improving fatigue and low-temperature cracking resistance is the diminishing rutting resistance of pavement. In this research, saturates, aromatics, resins, and asphaltenes (SARA)-separation, dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and bending beam rheometer (BBR) tests were conducted to study the interaction between chemical components and rheological behavior of binders with 25, 50, and 100 percentages of reclaimed asphalt pavement (RAP) binder modified with a softer binder and rejuvenator. The results show that the use of general guidelines for RAP content that do not consider the specific properties of all component materials in use has major limitations. The parameters obtained from rheological tests correlate positively with the asphaltene content. Using just asphaltene content as an index is more reliable than using Gastel and Asphaltene indices for investigating the effect of aging or adding an aged binder because its correlation with MSCR parameters is stronger. In this research, it also discovered that 100% of RAP content could be replaced in the case of an oil rejuvenator addition.