Investigation Into the Temperature Dependence of Surface Properties and Aggregate Adhesion of Base and SBS Modified Asphalts

Abstract

Addressing the frequent interfacial adhesive failure in high‐performance asphalt pavements, this study extends the characterization of interfacial energy from traditional low‐temperature, solid‐state conditions to high‐temperature molten states. The dynamic interface evolution mechanisms of base asphalt and SBS modified asphalt (at a dosage of 4.5%) were investigated between 120°C and 160°C. Using a self‐developed high‐temperature pendant drop in situ characterization system combined with the Young‐Laplace equation, the surface free energy (SFE) evolution of both asphalts was accurately determined. Dynamic contact angles on limestone, granite, and basalt surfaces were also measured. The results reveal that the SFE of both asphalts exhibits a linear decay with increasing temperature, while the SBS modified system (at 4.5% dosage), through its internal three‐dimensional physical cross‐linking network, exhibits a “thermodynamic anchoring action” that reduces temperature sensitivity. SBS modification significantly reduces the contact angle on aggregate surfaces, achieving a 28.8% reduction compared to base asphalt at 130°C, and maintains superior work of adhesion (48.18 mJ/m 2 at 140°C, a 33.5% increase) with high compatibility across different aggregates. Finally, a construction window optimization strategy based on the “viscosity‐adhesion dual‐control” principle is proposed, with suggested mixing temperature ranges of 140°C–160°C for base asphalt and 160°C–175°C for SBS modified asphalt.