Adhesion between Modified Binders and Aggregate Minerals at Ambient Conditions Measured with Particle-Probe Scanning Force Microscopes

Abstract

Accurate determination of adhesion between asphalt binders and aggregates is essential to pavement performance. In this study, particle-probe scanning force microscopes were used to measure the adhesion between mineral microspheres representing the primary aggregate constituents and various control (PG 64-22 and PG 58-22) and modified binders. Unit surface energies were collected to differentiate the adhesion between various aggregate-binder pairs. Results showed that the alumina-binder pair exhibited the highest adhesion among various combinations. No monotonic trends were detected for adhesion between silica-binder or calcium carbonate-binder pairs. Height and amplitude scans were also performed to characterize microstructural variations between different modified binders.