Evaluation of Performance of Quarry Dust as Additive for Stabilizing Black Cotton Soils

Abstract

This paper presents a laboratory investigation into the efficacy of quarry dust as an additiveforenhancing the strength characteristics of black cotton soil. Based on the AASHTO classification system and the USCS, the studied soil belongs to A-7-6(12) and CH respectively, implyingthat the soil is unfit for engineering purposes. The modification of the soil was carried out bytreatingthe soil with 0-30% by  weight of quarry dust in 5% increments. Results of compaction tests onthemodified soil indicated that, the maximum dry density  increases from 1.7 to 1.92 Mg/m³ asthemodifier is varied from 0-20%. Conversely, the optimum moisture content decreases from16-7.1%  for the same variation of the modifier. The CBR value also increases as the amount ofquarry dust is increased (from 9 when untreated to  19% when treated with 20%of additive), thusindicating that the additive has the tendency to enhance the strength characteristics of  theexpansive soil. Based on CBR criterion, the recommended percentage of modifier is 15, beingthesmallest quantity of quarry dust that  satisfies the criteria for a suitable sub-grade cover.