Evaluation of Adhesion Between Aggregate and Asphalt Binder in Multi-scale

The adhesion force between aggregate and asphalt binder is one of the important indicators of asphalt mixture performance, which has important effect on the durability of the road. The adhesion force between aggregate is influenced by many factors. In order to investigate the inf-luence of the inherent components of the aggregate on the adhesion force between aggregate and asphalt binder, the probe tip of the atomic force microscope (AFM) was modified: use the main compounds in aggregate to make small ball probe tips so as to measure the adhesion of the asphalt surface. Obtaining aggregates from the quarry attached to the road engineering project under construction, combined with X-ray fluorescence spectrometer (XRF) analysis and macro MTS pull-out test to investigate the effect of aggregate composition on aggregate-asphalt adhesion and conduct a comprehensive evaluation. The conclusion indicates that the adhesion between aggregate and asphalt binder includes physical adsorption and chemical adsorption. Large adhesion force occurs between Al2O3 and asphalt binder, the results measured at the nano level show that there is a strong intermolecular attraction between SiO2 and asphalt binder, while the intermolecular attraction between CaCO3 and asphalt binder is weak. The macro-level measurement results show that chemisorption has a stronger effect on the adhesion between aggregate and asphalt binder and the alkaline aggregate combined with asphalt binder have a stronger ability to resist water damage. The result has certain guiding significance of aggregate screening in road engineering. © 2021, Materials Review Magazine. All right reserved.