Abstract
To realize the efficient recycling of aged bitumen, it is of great significance to reveal the regeneration mechanismsof aged bitumen for the selection and design of rejuvenators. First, the physical properties and microstructureof mineral rejuvenators and biomass rejuvenators were investigated. Then, the diffusion behavior at theinterface between the rejuvenator and aged bitumen and the deagglomeration behavior of the rejuvenator on theagglomerates of aged bitumen were quantitatively characterized based on mechanical properties and structuralcharacteristics of recycled bitumen. Finally, the regeneration mechanisms of rejuvenators on aged bitumen wereanalyzed based on molecular dynamics simulations of colloidal interfacial diffusion behavior and colloidalstructural deagglomeration behavior. The results showed that mineral rejuvenators demonstrated better abilityto accelerate the diffusion at the colloidal interface of aged bitumen and virgin bitumen due to their smallmolecular weight and non-polar properties. However, the deagglomeration of aged bitumen colloid structure waslimited, mainly because the small moleculars could only fill the free volume of aged bitumen, but could noteffectively achieve the deagglomeration of asphaltene nanoclusters. Biomass rejuvenators exhibited weakdiffusion performance due to their macromolecular structure. However, they could effectively exert the sterichindrance effect to realize the deagglomeration of asphaltene nanoclusters, which was attributed to the fact thatthe functional group branched chain of biomass rejuvenators could exert pullout and intercalation effect todeagglomerate the asphaltene nanoclusters. The regeneration efficiency of aged bitumen is jointly determined bythe diffusion rate and the deagglomeration effectiveness of the base oil in rejuvenator. Therefore, balancing bothdiffusion capability and deagglomeration performance constitutes a critical consideration in the design anddevelopment of high-performance rejuvenators.
NETL
NSTL