Research on mechanical-activated nanoscale bentonite and surface aging behavior of its modified asphalt

The purpose of this study is to explore the influence of oil-milled bentonite on the aging behavior and mechanical properties of modified asphalt binders. In this paper, bentonite (BT) was used as the raw material, and waste engine oil (WEO) was used as the grinding medium. The nano-bentonite (OBT) was prepared through the liquid phase ball milling process. Liquid phase mechanical grinding and organic activation of bentonite with waste engine oil mixed with asphalt to modify asphalt. Through X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and surface area analysis (BET) was operated to study the structure and properties of nano-bentonite. The results showed that WEO successfully entered the interlayers of OBT, and the layer spacing was significantly enlarged. Through thin film oven test (TFOT), pressure aging test (PAV), nanoindentation, and universal testing machine experiments (UTM), the aging behavior and mechanical properties of nano-bentonite modified asphalt were tested. From the results, the introduction of OBT into asphalt significantly improved the surface anti-aging behavior of asphalt. The results of Fourier Infrared Spectroscopy show that WEO and the exfoliated OBT in modified asphalt could effectively delay the surface aging behavior of asphalt. The data of nanoindentation and UTM showed that OBT had the potential to optimize the low-temperature resistance of modified asphalt. The work provided a new method for solving the aging of asphalt materials and promoting nano-material modified asphalt, which had good prospects.