Characterization of Soil–Jarosite Mixes for Geopolymer-Based Soil Stabilization

In this study, an attempt is made to evaluate the compaction characteristics of soil–jarosite (SJ) mixes with an objective to check the feasibility of jarosite as a geopolymer binder for alkali-activated soil stabilization. Jarosite (waste from a Zn smelter) is first characterized in terms of its particle size distribution, specific gravity, Atterberg limits, and microstructure in order to draw comparisons with bare soil. Thereafter, two sets of SJ mixes, one with water and one with an alkali activator solution (NaOH), are then prepared with varying jarosite content. Results from the experiments reveal that jarosite is a silty soil with high plasticity (Ip = 16.71) having 72.8% silt and 26.6% clay-sized particles. Furthermore, the compaction tests revealed a rise in the optimum moisture content (OMC) and a drop in maximum dry density (MDD) with increase in the jarosite content. In addition, SJ mixes prepared with NaOH solution were observed to have lower MDD and higher OMC in comparison to those prepared with water. The findings of this study can be utilized to select a target dry density and OMC for sample preparation required for the strength determination of geopolymerized soil.