Abstract:This study investigates the modification effects and mechanisms of anti-stripping agents and surface modifiers on the adhesion performance of the asphalt-aggregate interface, based on a nano-micro-macro multi-scale model. By constructing six asphalt-aggregate interface models and conducting tensile simulations, it was found that the anti-stripping agent regulates the distribution of asphalt components through its polar groups. The polyethylene oxide chain in XT depolymerizes the saturated fraction, resulting in a bimodal distribution and driving the asphaltenes to concentrate at the interface. The silane coupling agent synergistically enhances the interface adhesion with LY anti-stripping agent. The phenolic hydroxyl group forms hydrogen bonds with the silane amino group, and the aromatic rings interlock with hydrophobic segments through π-alkyl interactions, leading to an 87.0% increase in interface energy (389 kcal/mol). The combined treatment strategy balances performance trade-offs, achieving an 87.0% increase in adhesion energy and a 300% increase in diffusion coefficient for the LY+Si group, indicating a synergistic enhancement of interface toughness and dynamic relaxation ability. Surface energy tests confirm that the simulation results are highly consistent with experimental data (LY+Si > XT+Si > LY > XT > BA+Si > BA), demonstrating that the nano-scale model can effectively predict the adhesion behavior of real materials and provides theoretical support for the application of tuff aggregates.
