Use of dimension limestone sludge as filler in asphalt mix

Abstract

This study investigates the feasibility of using waste dried sludge dust from the Indian dimension limestone (namely, Kota stone (KS)) industry in the place of conventional stone dust as filler in asphalt concrete mix. First, physical, morphological and chemical characteristics of both fillers were determined by relevant standards. Second, asphalt concrete mixes including both fillers were designed and their performance against primary occurrences of distress (rutting, cracking, long-term ageing, ravelling and moisture susceptibility) was evaluated. The KS mix had lower optimum asphalt content than conventional mixes, which was attributed to the lower porosity of KS dust. KS mixes also displayed superior resistance against permanent deformation, cracking and ravelling due to the finer nature of KS. Although the KS had a relatively high active clay content, KS mixes displayed good active and passive adhesion as well as satisfactory resistance against moisture permeation.