Effect of quarry dust (QD) particle on the strength, durability, and microstructure of lime stabilized lateritic sandy soil

Chemical soil stabilization by lime addition is used to improve soil properties and to ensure a suitable performance of natural soil. Sometimes chemical and granulometric stabilization combined is required to meet the requirements imposed by the geotechnical design. In this context, reusing waste materials in large-scale projects, besides improving the characteristics of the soil, can reduce the environmental impact of irregular disposal. Considering the importance of this issue, this paper presents the results of an experimental study of quarry dust (QD) addition on a lime-stabilized lateritic soil. The mixtures were prepared using soil, quarry dust proportions of 25%, 50%, and 75%, and lime contents of 7%, 9%, and 11%. The unconfined compressive strength was evaluated at 7, 14, 21, and 28 days of cure, and wetting-drying cycles were performed after 14 days of cure. The microstructure of samples with 9% lime and 28 days of cure was also considered. Regarding the results, it was observed that incorporating 25% of QD and 9% or 11% of lime into a lateritic soil is a viable material in terms of unconfined compressive strength and durability with better performance than natural soil. However, proportions of 50% and 75% of quarry dust decreased the soil strength. The microstructure of the natural soil and soil with 25% QD presented a more closed and interconnected structure. In contrast, the 50% and 75% QD soil mixtures presented a porous structure. Therefore, the proportion of the quarry dust addition demonstrated a critical parameter to be considered.