Abstract: In order to investigate the pavement properties of tourmaline anionic powder modified asphalt, modified asphalt with different contents of tourmaline anionic powder were prepared by a high speed shear method, then, the high and low-temperature performance, viscosity-temperature property were studied by means of the conventional physical performance test, multiple stress creep recovery test (MSCR), bending beam rheometry (BBR) and Brookfield viscosimeter test, respectively. The microstructure, chemical composition and thermal properties of the modified asphalt were characterized and analyzed by means of X-ray powder diffraction (XRD), Fourier infrared spectrometer (FT-IR), optical microscope and differential scanning calorimetry (DSC) so as to investigate the modification mechanism of tourmaline anionic powder from a microscopic perspective. The results show that tourmaline anionic powder can significantly improve the high and low-temperature performance and viscosity-temperature properties of asphalt by virtue of its excellent thermoelectric and piezoelectric properties. Moreover, tourmaline anionic powder can be dispersed uniformly in the base asphalt and form a kind of cavernous network structure, which can effectively improve the technical performance of asphalt. Compared with base asphalt, both the T_g and ΔH are sigificantly improved, and the modified asphalt exhibit a better thermal stability. There is only physical interaction between tourmaline anionic powder and asphalt.

Key words: tourmaline anionic powder, modified asphalt, temperature sensitivity, thermal stability