Adhesion mechanism of warm-mixed recycled SBS Modified Asphalt Binder: Surface free energy, microstructure and chemical compositions

Abstract

This study investigates the effects of aged asphalt binder content, rejuvenators, and warm mix agents on the adhesive properties, micro-morphological evolution, and chemical compositions of asphalt binder. Employing Surface Free Energy (SFE), Atomic Force Microscopy (AFM), Fourier-Transform Infrared Spectroscopy (FTIR), and Gel Permeation Chromatography (GPC) provided a comprehensive understanding. Aged asphalt binder reveals alterations in its microstructure and chemical components, influencing its adhesion capabilities. Rejuvenators counteract aging effects primarily physically and induce molecular transformations, while warm mix agents, including Fischer-Tropsch wax, alter asphalt binder's adhesive dynamics. A key finding is the correlation between asphalt's microstructure and chemical composition, both crucial in determining adhesive behavior. This study emphasizes the need for combined micro-level and macro-level analyses in asphalt binder research.

Keywords

• Warm mixed recycled
• SBS modified asphalt
• Surface free energy
• Microstructure
• Chemical composition
• Adhesion properties