Organic soil deposits are often unsuitable for safely bearing structural loads without proper soil stabilization measures. Sustainable methods of soil stabilization are gaining attention, with nano-additives showing promising effects owing to their high reactivity and better soil interaction. The present study attempts to investigate the feasibility of treating a low-plasticity organic silt soil using chitosan nanoparticle (CNP) additive, a crustacean polysaccharide. The modifications in the soil plasticity index (PI), compaction, unconfined compressive strength (UCS), permeability and consolidation properties were studied for 0.5 to 2.5% CNP addition, considering the curing period durations of between 0 and 90 days. Results showed that 1% CNP addition produced a better outcome in terms of geoengineering properties. For instance, compared to the untreated soil, the compacted 1% CNP-treated soil achieved a 146% UCS gain and 69% permeability coefficient reduction for 90-day curing, with negligible change in the coefficient of consolidation. Whereas 2.5% CNP-treated soil exhibited a comparatively smaller UCS gain (of 100%), along with a 59% permeability coefficient reduction for 90-day curing. SEM analysis indicated that the CNP additive enhanced the geomechanical properties by forming a fibrous network in the soil matrix. Finally, a critical discussion has been presented on the aspects of necessity of nano-based soil stabilization, cost analysis and material degradation effects to understand the suitability of the technique for practical applications.
Kannan et al. (Sun,) studied this question.