Study on adhesion between asphalt binders and aggregate minerals under ambient conditions using particle-modified atomic force microscope probes

• An experiment is presented to characterize the aggregate–binder adhesion at microscale.
• The particle probes are made from alumina, silica and calcium microspheres.
• The aggregate–binder adhesion are quantified for different PG binders and modifications.

Adhesion between asphalt binders and aggregates is critical to the performance of asphalt mixtures, which have been widely used in pavement systems. In this work, the authors presented an effective approach in quantitative characterizing the adhesion between binders and aggregate mineral particles at the microscopic scale. Attaching to cantilever ends with microspheres of alumina, silica and calcium carbonate, the adhesion between aggregate minerals and binder substrates at ambient conditions was measured directly using atomic force microscopes. In the three groups, it is found that the unit surface energy is largest in the alumina–binder pair and relatively smaller in the calcium carbonate- and silica–binder pairs.