Utilization of dolerite waste powder for improving geotechnical parameters of compacted clay soil

This study explores how dolerite cutting waste could be utilized for improving the quality of compacted clay soils. Different proportions of dolerite waste powder with varying grain sizes were used as admixtures and their impact on clay soil properties investigated. Ten samples were prepared by mixing clay soil with different proportions of dolerite waste powder having grain sizes of 0.210, 0.297, and 0.420 mm. The resulting samples were subjected to Proctor compaction, and their maximum dry density and optimum moisture content were measured. Next, all the compacted samples were subjected to geotechnical testing, including the determination of Atterberg limits, California bearing ratio (CBR), unconfined compressive strength, and specific gravity (Gs). The values of compaction parameters, Atterberg limits, and Gs were utilized for finding the porosity, void ratio, saturation potential, liquidity index (LI), and consistency index (CI). The results demonstrate that the addition of dolerite powder produces a substantial improvement in the plasticity index, compaction parameters, CBR, unconfined compressive strength, Gs, porosity, void ratio, degree of saturation, LI, and CI. The foremost reason for this improvement is the presence of denser and less water-adoring minerals in the added dolerite relative to pristine clay soil. Furthermore, the observed positive impact on the soils’ geotechnical comportment is comparatively higher with coarser than finer dolerite because of the decrease in surface area that causes a reduction in the moisture content and porosity but an increase in the density of soil.