Influence of silane-hydrolysate coupling agents on bitumen–aggregate interfacial adhesion: An exploration from molecular dynamics simulation

Abstract The objective of this research was to investigate the influence of silane-hydrolysate coupling agents on various parameters of the interfacial adhesion between bitumen and mineral aggregate by applying molecular dynamics (MD) simulations. The simulation was based on the 12-component molecular model of AAA-1 bitumen, and the molecular models of two types of mineral aggregate (SiO2 and CaCO3) and two silane-hydrolysates (KH550 and KH792). The results demonstrated that the interfacial adhesion energy significantly increased by the surface treatment of aggregate by silane-hydrolysates, whereby the hydrolysate KH792 had a much stronger effect than KH550. Both silane-hydrolysates increased the debonding energy between the SiO2 aggregate but decreased for the CaCO3 aggregate. The theoretical basis provided by this research enables a better understanding of the influence of silane-hydrolysates on the adhesion performance between bitumen and different aggregate types.