Mechanical and Microstructural Characterization of a Nano-stabilized Sandy Soil

This research investigates the potential of using nanoparticles, Poly Aluminum Silicate and Poly Calcium Silicate, and industrial by-products, Recycled Glass Powder (RGP) and Ground Granulated Ballast Furnace Slag (GGBS) to enhance the durability and strength of a sandy soil, particularly in wet or saturated conditions where water table is close to building foundations. The study aims to determine the optimal content and concentration of additives and assess their influence on the compressive strength and the failure strain. The optimal content and concentration of dry additives and alkaline solutions were determined. Uniaxial compressive strength tests were conducted on various stabilized geopolymers, considering factors such as alkaline activator type, nanoparticle type and percentage, and degree of saturation. Scanning electron microscopy images were taken and analyzed to verify geomechanical testing outcomes. Mixtures with nanomaterials exhibited greater strength than untreated soil, with some exhibiting up to a tenfold increase. GGBS-based samples displayed a twofold increase in strength with nanomaterial addition, while RGP-based samples experienced reduced strength. However, both nanomaterials addressed the durability concerns in wet conditions. The addition of 2% nanomaterials to GGBS-based mixtures led to significant strength gains, with some showing a 20% increase after saturation. This research indicated the potential of nanoparticles and industrial by-products in resolving a major concern regarding geopolymers which is the lack of durability in wet or saturated conditions. These findings have implications for eco-friendly geoconstruction materials and practices.