Performance evaluation of bamboo leaf ash and steel slag powder as alternative filler in asphaltic mixes

Abstract

The need to improve the quality of asphalt concrete and to control the disposal of waste into the environment has been an issue of concern to most researchers. This study investigated the re-use of bamboo leaf ash (BLA) and steel slag powder (SSP) as replacements for conventional mineral filler, quarry dust (QD). Asphaltic concrete binder (BC) and wearing (WC) courses were prepared with SSP and BLA, while QD was used as control. Laboratory tests were carried out on the BC and WC to determine the Marshal and mechanical properties of the mixes. The properties are stability, flow voids, indirect tensile strength, tensile strength ratio, fatigue test, resilient modulus, cantabro loss test, skid resistance, and retain strength. The performance of asphalt mixtures containing SSP improved the marshal stability, indirect tensile test, ravelling resistance, and rutting resistance of the asphaltic concrete by 10, 15, 20, and 25%, respectively, more than the control compared to BLA. The moisture resistance, fatigue, and resilience moduli of the control (QD) were found to be a little higher than the SSP and BLA, with 15, 20, and 25%, respectively. The use of BLA and SSP is cheaper as compared to conventional fillers; BLA and SSP for wearing and binder courses are 4.35%, 4.13%, and 3.17%, 3.03% lower respectively, for 1 tonne of asphalt concrete produced. The result of this study suggests that re-using SSP and BLA can be a substitute for conventional filler to achieve a more satisfactory performance, cost-effectiveness, and a means of effective waste disposal.