Multi-Scale Mechanisms of Nano‑Silica Stabilization in Clayey and Sandy Soils

Abstract

This research investigates the multi-scale mechanisms of nano-silica stabilization in clayey and sandy soils. The term "multi-scale mechanisms" refers to interactions at the microstructural scale (SEM/XRD analysis), particle scale (interparticle bonding and pore filling), and macro scale (strength, compaction, and durability behavior). The study focuses on understanding how nano-silica dosage, dispersion quality, and curing conditions influence soil fabric, interparticle bonding, mechanical strength, and durability. A comprehensive experimental program will be conducted, including index property tests, compaction tests, unconfined compressive strength tests, direct shear tests, shrink-swell tests, and freeze-thaw durability tests. The experimental program considers curing periods of 7, 60, and 90 days to capture the evolution of strength and durability with time. Microstructural characterization using scanning electron microscopy (SEM) and X-ray diffraction (XRD) is employed to examine changes in soil structure and cementitious bonding mechanisms. In addition, statistical analyses using ANOVA and simple additive weighting will be applied to identify statistically significant performance improvements, determine the optimum nano-silica dosage, and quantify relationships between microstructure and engineering performance.