Fine solid wastes as a resource-conserving filler and their influence on the performance of asphalt materials

Abstract

Abstract Currently, the reuse of fine solid wastes (FSW) as cleaner production, instead of raw material, helps in improving road performance, easing excavation of virgin material and reducing environmental pollution. Nevertheless, concerns over poorer pavement performance caused by the addition of FSW have hindered the prevalent reusing of FSW in pavement engineering. Therefore, seven types of filler with five filler-binder volume ratios (FBv) were selected to prepare thirty-five types of asphalt mortar, in this study. The relationships among diversities of physical and chemical indexes of seven types of filler were firstly analyzed. Then, stripping test was applied to investigate the moisture sensitivity of asphalt mortar. After that, the effect of FBv and Rigden void of filler on the performance of asphalt mortar was evaluated. Moreover, the mechanism for the impact of FSW on the property of asphalt materials was comprehensively studied based on the rheological, mechanical and microscopic performances. Additionally, environmental impact of filler and mixture in the early stage was evaluated. In conclusion, the moisture damage mechanism of mixture in terms of surface free energy theory and asphalt mortar system was revealed, which indicated that the effect of filler on binder can be classified into four mechanisms; “physical hardening”, “chemical bonding”, “moisture instability” and “polarity enhancement”.