Influence of rejuvenator components on rheological properties of recycled bitumen in the full temperature range

Abstract

Recovering aged bitumen from reclaimed asphalt pavement (RAP) is crucial for the evolution of pavement recycling. This study delves deeply into the effects of rejuvenator components on the rheological properties of rejuvenated bitumen across a wide temperature range. The investigation utilized the rolling thin film oven test (RTFOT) and the pressure aging vessel (PAV) test to simulate the short-term and long-term aging of the bitumen binder, respectively. Four distinct rejuvenators were then applied to recover the bitumen at varied aging levels. Detailed chemical analyses, encompassing the four-fraction (SARA) method and Fourier transform infrared spectroscopy (FTIR), were employed to identify the chemical compositions and key functional groups of both the rejuvenators and the rejuvenated bitumen. The rheological behavior of rejuvenated bitumen was assessed through a comprehensive series of tests, including conventional, temperature sweep, frequency sweep, multiple stress creep recovery (MSCR), linear amplitude sweep (LAS), and bending beam rheometer (BBR) tests. A Pearson correlation analysis highlighted a significant positive association between specific rejuvenator components, notably asphaltene (As), saturate (S), and aromatic (Ar), and the high-temperature performance of the rejuvenated bitumen. The findings of this research offer insights into the formulation of rejuvenators, potentially enhancing the performance of rejuvenated asphalt pavements and facilitating sustainable infrastructure advancements.