Mechanistic insights into restoring severely aged asphalt using sustainable rejuvenators from molecular to macroscopic scales

This study presents a multiscale investigation into the rejuvenation mechanism of thermally oxidatively photochemically aged asphalt through integrated experimental characterization, molecular dynamics (MD) simulations and quantum chemical (QC) calculations. Four environmentally friendly rejuvenators, epoxidised soybean oil (ESO), waste cooking oil (WCO), waste engine oil (WEO) and naphthenic oil (NO), were evaluated for their efficacy in restoring the physicochemical properties of severely aged asphalt. The experimental results demonstrate that the addition of these rejuvenators effectively reduces the viscosity of aged asphalt by more than 90% (at a 0.1 s−1 shear rate), rebalances the SARA fraction by…