Experimental study on the aging behavior of modified asphalt with different types of fine solid wastes under different aging conditions

Abstract

Both Fine solid wastes (FSW) and various modified asphalt have been gradually applied in road construction for sustainable development and better performance. However, when considering the aging resistance of modified asphalt, present study on the effect of FSW like red mud and diatomite on the aging behavior of asphalt mortar is poorly documented. This research utilized limestone powder (LSP), fly ash (FA), diatomite, and red mud (RM) to estimate the impacting level of FSW and aging after 0 h PAV aging, 5 h PAV aging, and 25 h PAV aging. Firstly, the variations of chemical groups of modified asphalt/mortar were analyzed by carbonyl index test. Furthermore, the low and high temperature properties of modified asphalt/mortar were investigated based on Performance Grade test (PG), Muti-Stress Creep and Recovery test (MSCR), and Low-temperature Shear Stress Relaxation tests (SSR). Additionally, Binder Bond Strength test (BBS) and Linear Amplitude Sweep test (LAS) were carried out to indicate and evaluate the change of adhesion/cohesion property and the fatigue property of modified asphalt/mortar in the aging process, respectively. The test results showed that red mud and diatomite could enhance the aging resistance of modified asphalt much better than fly ash and limestone powder. And aging resistance was the comprehensive results of oxygen permeating, diffusion, and fusion inside the asphalt mortar, adsorption of porous fillers on light components. Besides, comparing with the variation of the index of elastic damage in MSCR test, different fillers showed weak differences in high-temperature property after short-term aging in PG test. The differences of low-temperature property among the modified asphalt/mortar with different FSW were minor after 5 h PAV aging, but significant after 25 h PAV aging. And the effect of hardening asphalt and filling particle would compete and decide the fatigue property jointly.