关键词: 道路工程；石灰岩填料；理化性质；沥青胶浆；流变性能；沥青吸附膜厚度

Abstract: To clear the effect of the physicochemical properties of fillers on the rheological properties of asphalt mastic, dynamic shear rheological (DSR) tests, multiple stress creep recovery (MSCR) tests and bending beam rheological (BBR) tests were employed to study the effects of high and low temperature performances of SBS-modified asphalt mastic, which was based on the differences in physicochemical properties of limestone fillers from three different sources. Utilizing the thickness of asphalt adsorption film as a link, the influence mechanism of the physicochemical property differences of fillers on the rheological properties of asphalt mastic was analyzed. Subsequently, a grey correlation analysis model and two-factor variance analysis were employed to analyze the correlation and coupling effects of influencing factors. The research results indicate that as the volume fraction of filler increases, the thickness of the asphalt adsorption film is increased, the complex modules and rutting factors of asphalt mastic are increased, and high-temperature rheological properties and resistance to deformation are enhanced. Meanwhile, the creep stiffness of asphalt mastic increases, while the creep rate decreases, resulting in a reduction of low-temperature stress relaxation capacity and a deterioration of low-temperature crack resistance of the asphalt mastic. Furthermore, the greater disparities in physicochemical indicators of fillers such as specific surface area, alkaline component content, average particle size, the more significant effect on the rheological properties of asphalt mastic. Specifically, the larger specific surface area of filler, the higher alkaline component content and the smaller particle size, the better high-temperature performance but the worse low-temperature performance for asphalt mastic. The correlation between the physicochemical property indicators of fillers and the rheological properties of SBS modified asphalt mastic is ranked from high to low as follows: filler volume fraction > specific surface area > average particle size> CaO content > SiO2 content > MgO content.

Key words: highway engineering; limestone filler; physicochemical properties; asphalt mastic; rheological properties; thickness of asphalt adsorption film