Investigating asphalt aggregate bonding degradation through aging and temperature effects using multiscale testing methods

Moisture damage in asphalt mixtures is a critical durability concern influenced by interfacial adhesion between asphalt and aggregates. This study systematically evaluates adhesion performance using digital image analysis and surface energy theory across four asphalt types (OR50, OR70, OR90, ORSBS) and five aggregates (limestone, basalt, granite, diabase, diorite). Key findings reveal that limestone exhibits superior adhesion stability (100% adhesion rate under aging) due to chemical bonding, while acidic aggregates (e.g., granite) show significant sensitivity to moisture and aging. A novel quantitative method combining water immersion tests and pixel-based stripping area analysis demonstrated high correlation (R² > 0.9) with surface energy-derived ER values, validating its reliability. Temperature and aging effects were further quantified, showing adhesion loss under thermal/oxidative aging, with SBS-modified asphalt outperforming base binders. These results provide a robust framework for material selection in pavement design, emphasizing aggregate alkalinity and polymer modification as key factors for moisture resistance.