Impact of particle morphology on aggregate-asphalt interface behavior

This paper researched interfacial adhesion behavior between asphalt with limestone and granite through surface microtopography comparison. Abrasion was conducted to limestone and granite by Los Angeles Abrader. Angularity coefficient was used to analyze the angularity and roughness changes of limestone and granite before and after abrasion. Digital imaging technique was used to study the macroscopic changes on the particle surface of limestone and granite before and after abrasion. Scanning electron microscope was used to characterize the changes of surface microtopography of limestone and granite before and after abrasion and the interfacial morphology with asphalt binder. The result showed that the texture complexity degree on the particle surface of limestone and granite decreased after abrasion, the relative flat site of surface increased, and the surface texture change of limestone was more significant. The test result of scanning electron microscope showed that asphalt could permeate into the surface texture of particles of limestone longitudinally after limestone was mixed with asphalt to form embedded structure, but there was a single surface adhesion in the interface between granite and asphalt that an embedded structure was not formed.