A Multi-scale Study of SBS Modified Asphalt-Aggregate Adhesion Under Moisture Damage

Adhesion is easily affected by moisture erosion, thus reducing pavement performance. SBS modified asphalt is widely used in road engineering due to its excellent performance. For analyzing the adhesion properties between SBS modified asphalt and aggregates under moisture damage, the macro-scale SBS modified asphalt-coated aggregates and micro-scale asphalt-aggregate adhesion models were prepared first. The moisture damage was applied to the coated aggregates and adhesion models subsequently. After that, the quantitative boiling tests and molecular dynamics (MD) simulations were carried out. Finally, the multi-scale adhesion results were analyzed using Pearson correlation analysis. The macro-scale results imply that as the degree of moisture damage increases, the stripping area of the asphalt-aggregate interface rises. The micro-scale results reveal the moisture damage mechanism that is the penetrated moisture into asphalt-aggregate interface disrupt the adhesion force by the action of hydrogen bonds and Van der Waals forces. The Pearson correlation coefficient is 0.996, which indicates that the multi-scale adhesion results present an extremely strong linear relationship. This research contributes to the analysis of moisture damage in asphalt pavements in pluvial as well as seasonal frozen regions, and also provides a reference for correlation analysis between the multi-scale results.