Investigation of rutting, fracture and thermal cracking behavior of asphalt mastic containing basalt and hydrated lime fillers

Abstract

The present study was undertaken to evaluate rutting, fracture and thermal cracking resistance behavior of asphalt mastic containing inert and active fillers. A control neat binder (AC-30) along with basalt (B) as an inert filler and hydrated lime (HL) as active filler were selected in this study. The asphalt mastics were prepared for different percentages of HL (5, 10, 15 and 20%) filler, in such a way that Filler to Binder (F/B) ratio becomes 0.8. A total of five combinations of asphalt mastic were prepared such as: AC-30+80% B+0% HL, AC-30+75% B+5%HL, AC-30+70% B+10%HL, AC-30+65% B+15%HL, and AC-30+60% B+20%HL. The rutting, fracture and thermal cracking resistance of asphalt mastics was evaluated using Superpave rutting factor parameter, Double Edge Notched Tension (DENT) and Bending Beam Rheometer (BBR), respectively. Influence of HL on the performance of neat asphalt mastic was observed to be predominant in high-temperature range as obtained from the G∗/Sinδ value. The aging resistivity of asphalt mastic increased with the inclusion of HL, indicating a better rutting performance of asphalt mastic. The intermediate-temperature performance of asphalt mastic with HL was found to be higher compared to neat asphalt mastic from Critical Tip Opening Displacement (CTOD) results, implying better resistance to fracture. The addition of HL increased the low-temperature performance of asphalt mastic obtained from S(t) and m(t) values with S(t) and E(t) master curve, indicating enhanced resistance to thermal cracking. The combined effect of B and HL filler on the G∗/Sinδ, CTOD, S(t), m(t) and E(t) parameters are presented in this study. In addition, ranking of asphalt mastics based on various parameters (i.e. CTOD and m(t)) is discussed in this paper.