Influence of Basalt, Hydrated Lime, and Fly-Ash Fillers on Aging Behavior of Asphalt Mastic Using Essential and Plastic Work of Fracture

Abstract

Abstract The present study was undertaken to investigate the influence of Basalt (B), Hydrated Lime (HL), and Fly-Ash (FA) fillers on aging behavior based on the fracture properties of asphalt mastic. The asphalt mastic samples were prepared in the laboratory using an AC-30 asphalt binder with various combinations of B-HL and B-FA fillers by maintaining a constant filler-binder ratio of 0.8:1 (by mass ratio and 22.5 % by volume). The HL and FA contents were selected as 0 %, 5 %, 10 %, 15 %, and 20 % by the weight of the asphalt binder, and the content of B filler was adjusted accordingly. Correspondingly, three types of asphalt mastic samples, namely, unaged, short-term aged, and long-term aged were prepared in the present study to understand the effects of oxidative aging. Fracture properties of asphalt mastic samples were evaluated at an intermediate temperature using a Double Edge Notched Tension test. The analysis of fracture behavior includes the load-displacement curve pattern, Total Work of Fracture (TWF), Essential Work of Fracture (EWF), Plastic Work of Fracture (PWF), and Critical Tip Opening Displacement (CTOD) values. The results showed that nature, surface texture, mineralogy, and interaction ability of HL and FA fillers strongly influence the aging and fracture resistance of the asphalt mastic. The load-displacement curve pattern, TWF, and PWF values signify a clear indication of an increase in ductile behavior with the incorporation of HL or FA fillers. Similarly, the EWF and CTOD values showed that the inclusion of HL or FA fillers in the asphalt mastic enhanced the aging and fracture resistance behavior. The inclusion of the HL filler has a predominant impact in comparison to the FA filler in the enhancement of both the aging and fracture resistance of asphalt mastic.