Micro- and Nano-Characteration of Interaction Between Asphalt and Filler

This study explored the testing technologies characterizing the interaction between asphalt and filler. An atomic force microscope (AFM) was used to describe the surface morphology and surface adhesion force of asphalt mastic and analyze their effect factors. Fourier transform infrared spectroscopy (FTIR) was used to analyze the physicochemical interaction between asphalt and filler. Adsorption tests were used to study adsorption and desorption properties of asphalt on aggregate. The results show that andesite aggregate had a smoother surface and a weaker adhesion force than granite aggregate. The greater the asphalt penetration, the stronger the surface adhesion force. A small number of filler material increased the adhesion force of the asphalt mastic, but too much filler decreased the adhesion force. FTIR tests were employed to explore the various functional groups of asphalt and fillers. No obvious new stretching vibration peak or deformation vibration peak indicated that the interaction between asphalt and filler was mainly a physical action. Net absorption test revealed that the greater the equilibrium concentration, the greater the adsorption amount. Distilled water stripped asphalt from aggregate. The type of adsorption isotherm corresponded to multi-molecular layer adsorption that further indicated that the interaction between asphalt and fillers was mainly a physical action.