Experimental investigation on related properties of asphalt mastic with activated coal gangue as alternative filler

Abstract

To evaluate the feasibility of using activated coal gangue (ACG) as replacement of mineral filler in asphalt mixture, some properties of asphalt mastic containing ACG were investigated in this paper, compared with the traditional limestone mineral filler (LMF). The investigated mastic consisted of asphalt and filler at a mass ratio of 1:1. Cone penetration test (CPT), Dynamic Shear Rheometer test (DSR), Brookfield viscosity test (BVT) and Dynamic Mechanical Thermal Analysis (DMTA) were applied to research the shear resistance rheological property, rutting resistance, high-temperature viscosity characteristics and low-temperature property of asphalt mastic. With the application of scanning electron microscope (SEM) and Infrared Spectroscopy (IR), the mechanism of ACG imposed on asphalt mastic was analyzed. Results indicate the possibility of ACG as inorganic filler derived from solid waste to improve the performance of asphalt. The ACG has better effect on improving the shear strength and temperature sensitivity of asphalt mastic than LMF. Besides, ACG has positive effect on high-temperature properties while some negative effect on low-temperature properties of asphalt mastic. The results also indicate that the physical adsorption between the ACG filler and asphalt binder is the main mode of action.