Experimental investigation of the interface interaction between asphalt binder and mineral filler from the aspects of materials properties

The strength of the interface between asphalt and filler is relatively low, making it susceptible to stress concentration and damage, which can affect the service life of the asphalt pavement. Current research indicates that there is a significant relationship between the interfacial interaction behavior and the properties of both asphalt and filler. Based on this, this study investigated the influence of both asphalt and filler properties on the interaction behavior of the asphalt-filler interface. Firstly, this study conducted research on existing interaction evaluation indicators and selected Palierne C as the optimal evaluation indicator for this study, which has the weakest correlation with filler volume fraction, in order to avoid the influence of filler volume fraction on experimental results. Secondly, this study analyzed the effects of asphalt SARA components and aging degree on the interface interaction ability between asphalt and fillers, as well as the rheological properties of asphalt. The research results found that the asphaltenes and resins fractions can enhance the interaction ability between asphalt and filler, as well as the high-temperature performance of asphalt. The content of these fractions was positively correlated with the interaction between the interfaces. In contrast, the content of aromatics and saturates fractions was negatively correlated with the interaction capacity. The strength of the interaction was negatively correlated with aging time, and long-term aging inhibited interface interaction to a greater extent than short-term aging. Finally, the mineral and chemical composition of common fillers were analyzed by X-ray diffraction (XRD) and X Ray Fluorescence (XRF). Subsequent studies were carried out on the interaction of the asphalt-filler interface in terms of the mineral composition, chemical composition, and particle size of the filler. It was found that in terms of mineral composition, albite and asphalt have the strongest ability to interact at the same temperature, followed by calcite and the weakest by quartz. In terms of chemical composition, the strongest interaction was between MgO and asphalt, followed by CaO, Fe2O3 and Al2O3, and the interaction between SiO2 and asphalt was the worst. In addition, the smaller the particle size of the filler, the greater the interaction capacity.