Suitability of granite stone slurry dust and lime sludge for stabilising compacted black cotton soil

Abstract

This paper explores the potential of combining industrial wastes, specifically granite stone slurry dust (GSSD) and lime sludge (LS), to stabilise expansive black cotton (BC) soil for engineering applications. Lime is known for its effectiveness in soil stabilisation due to its pozzolanic properties. However, the environmental impact of lime is a concern since its production emits greenhouse gases. Hence, this study examines the partial replacement of lime with GSSD and LS through comprehensive laboratory experiments. The research evaluates the influence of moulding water content on the consolidation and strength behaviour of the soil. The findings indicate that a GSSD content of 30% is optimal for enhancing the properties of BC soil. Subsequently, BC soil samples with 30% GSSD were tested to assess the impact of LS. The experimental findings show improved compaction and consolidation characteristics (notably lower compression and recompression indices) and enhanced unconfined compressive strength (UCS). Additionally, samples that contained higher moulding water content exhibited better consolidation behaviour and reduced swelling potential. As expected, the UCS values remained high at the optimal water content. Overall, the use of GSSD not only reduces the reliance on lime but also improves the consolidation and strength of BC soils, thereby promoting eco-friendly waste-to-wealth stabilisation methods and contributing to UN Sustainable Development Goal 12.