Effects of Sodium Nanoalginate and Lime on Swelling Properties of Expansive Soils

Abstract

The findings revealed that the addition of nanoalginate and lime had distinct effects on various soil properties. Specifically, the liquid limit (LL) and plastic limit (PL) decreased when sodium nanoalginate and lime were added, while the plasticity index (PI) and shrinkage limit (SL) increased. Furthermore, the soil classification was altered when sodium alginate and lime were introduced to the control soil. Regarding the standard Proctor test, it was observed that adding sodium nanoalginate increased the maximum dry density and reduced the optimal moisture content, whereas lime had the opposite effect by decreasing the maximum dry density and increasing the optimal moisture content. The free swelling and swelling pressure tests indicated that the incorporation of sodium nanoalginate and lime reduced both free swelling and swelling pressure. The most significant reduction was observed in the sample containing 7% sodium nanoalginate and 5% lime. Additionally, the study highlighted the influence of processing time, showing that an increase in the curing time led to a decrease in free swelling and swelling pressure in samples mixed with 3% sodium nanoalginate and lime. The XRD test showed that adding sodium nanoalginate reduced primary minerals, forming SAH, while lime reduced quartz and calcite, creating CSH. Overall, the results suggest that sodium nanoalginate can be a more environmentally friendly alternative to lime for soil stabilization projects.