Performance assessment of waste glass powder in sandy soil stabilization: Effect of alkaline activator on mechanical and microstructural properties

• A geopolymer based on waste glass powder was studied to enhance the compressive strength of sandy soil. • Comparison of Sodium hydroxide and potassium hydroxide as alkaline activators was investigated. • The alkaline activator mixing method was evaluated in dry and solution form. • XRD, FTIR, and SEM analyses confirmed the formation of aluminosilicate products in the stabilized soil specimens. • Waste glass powder-based geopolymer can be used in geotechnical engineering projects and construction as an environmentally friendly material. The rapid increase in waste glass and its harmful environmental effects emphasize the need for environmentally friendly recycling methods and sustainable waste management practices. This research investigated the potential application of geopolymer based on waste glass powder (WGP) for soil stabilization. Unconfined compressive strength (UCS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) tests were conducted to evaluate the mechanical and microstructural properties of stabilized, poorly graded sandy soil. WGP was investigated as a precursor with varying contents, 30% to 60%. At the same time, sodium hydroxide and potassium hydroxide were examined as alkaline activators at 10, 12.5, and 15 molar concentrations, which were added to the mixture in both dry and solution forms. The stabilized specimens were tested after three curing times of 7, 28, and 91 days. The results indicated that WGP-based geopolymer significantly improved the UCS compared to untreated soil. Additionally, statistical analysis established that curing time pointedly impacted UCS. The Taguchi method and ANOVA determine the optimal material mix and factor importance, respectively. These discoveries emphasize the significance of utilizing WGP-based geopolymer for soil stabilization, promoting waste efficiency in the construction industry, and providing a greener substitute to old-style binders.