Effect of using fly ash as alternative filler in hot mix asphalt

Abstract

This study investigates the effect of using fly ash (FA) in asphalt mixture as replacement of common filler. In view of the same, samples were prepared for different bitumen content (3.5−6.5% at 0.5% increments) by using 2% hydrated lime (HL) in control mix as well as varying percentage of FA ranging from 2 to 8% as alternative filler in modified mixes. The optimum bitumen content (OBC) was then determined for all the mix by Marshall mix design. Experimental results indicated higher stability value with lower OBC for the mixture having 4% FA as optimum filler content in comparison with conventional mix and standard specification. So this study discuss the feasibility of using FA as alternative filler instead of HL in asphalt concrete mix by satisfying the standard specification.