Mingen Fei, Weijian Wu, Qingbing Cai, Huaye Yu, Xiaoli Yan, Shuyi Wu, Xin Zheng, Xueqiang Liu, Wendi Liu, Renhui Qiu
Recycled asphalt materials incorporating high percentages of reclaimed asphalt pavement (RAP) often suffer from brittleness and insufficient stability. Rejuvenators are usually employed to address this issue by restoring the aged asphalt in RAP. However, conventional rejuvenators often lack sustainability due to their feedstock sources, while many biobased alternatives may not possess the suitable molecular structure to be effectively compatible with aged asphalt. Herein, a palm oil-based rejuvenator, palm oil fatty acid-ethyl acrylamide (POFA-EA), was developed to soften the aged binder and improve the performance of recycled asphalt mixtures. Molecular dynamics simulations were employed to examine the compatibility and interactions between POFA-EA and asphalt components, providing theoretical validation for the rejuvenation mechanism. POFA-EA’s rejuvenating efficacy was evaluated using Fourier transform infrared spectroscopy, gel permeation chromatography, and dynamic shear rheological tests. Analytical results demonstrated that POFA-EA dispersed asphaltene clusters, transforming aged asphalt into a stable colloidal system while reducing material brittleness. Compared to the control mixture, POFA-EA incorporation enhanced Marshall stability by 7.3% and indirect tensile strength by 13.2%, while achieving balanced road performance across high and low temperatures. Moisture susceptibility tests revealed residual Marshall stability and tensile strength ratios of 89.6% and 91.6% following immersion and freeze–thaw conditioning, respectively. Overall, POFA-EA proves effective in rejuvenating aged asphalt by restoring binder properties and enhance cohesion within the recycled asphalt mixtures. • A new palm oil rejuvenator POFA-EA was developed and characterized. • POFA-EA shows compatibility with aged asphalt and strong binding with asphaltene. • Analytical results on recycled binder elucidate POFA-EA’s rejuvenating efficacy. • The incorporated POFA-EA enhanced asphalt mixtures’ mechanical performance.