ABSTRACT
This paper summarizes the findings from a study conducted to closely examine the nature and influence of microstructures in asphalt binders on its rheological properties. A combination of rheological measurements, optical measurements using different techniques, and differential scanning calorimetry were used. Results show that microstructure on the surface of the binder commonly observed using devices such as the Atomic Force Microscope (AFM) is unique to the binder-air interface and different from the microstructure in the bulk of the binder. This study also quantitatively demonstrates the influence of the bulk microstructure on the rheological properties of the binder. A key conclusion of this study is that it is more critical to investigate and model the influence of the bulk microstructure as opposed to the surface microstructure.
