Evaluation of Sbr Asphalt Modification Mechanism and Adhesion Effect Based on Molecular Simulation

Abstract

Recycled rubber materials represent an environmentally sustainable option as asphalt modifiers. This research delves into the modification effects of Styrene Butadiene Rubber (SBR) asphalt at varying SBR content levels, employing a blend of molecular simulation techniques and laboratory experimentation. A comprehensive molecular model of SBR-modified asphalt is established, and molecular dynamics simulations are executed to scrutinize the thermodynamic attributes, dipole moments, mechanical characteristics, and adhesion properties inherent to SBR asphalt. The outcomes of this inquiry reveal that SBR exhibits notable compatibility with a majority of asphalt molecules, as evidenced by their dipole moments. The introduction of SBR into the asphalt matrix results in the adsorption of a substantial quantity of lightweight components, fostering the formation of a cross-linked network that bolsters the asphalt's resilience against external deformation forces. Furthermore, in terms of adhesion work, asphalt demonstrates heightened affinity with alkaline aggregates, and SBR serves to augment van der Waals interactions at the asphalt-aggregate interface, thereby amplifying interfacial bonding strength. Nevertheless, it is observed that at a SBR content threshold of 30%, certain SBR molecules exhibit proclivities toward aggregation within the asphalt matrix, leading to phase separation phenomena that affect colloidal stability. Consequently, in practical engineering applications, an optimal SBR content of approximately 20% is recommended. The findings derived from this research provide valuable theoretical insights for the judicious incorporation of recycled SBR powder in asphalt applications.

Keywords: SBR asphalt, Molecular dynamics, compatibility, rheological properties, modification effect, interfacial adhesion.