ABSTRACT
The construction industry's increasing demand for sustainable practices has inten-sified efforts to reduce the environmental impacts of traditional soil stabilization methods. Ordi-nary Portland Cement (OPC), widely used for ground improvement, contributes significantly to global carbon emissions. This study explores the effectiveness of Supplementary Cementitious Materials (SCMs), specifically Ground-Granulated Blast-Furnace Slag (GGBS) and Biochar, as partial OPC replacements in clay soil stabilization. Clay soil was mixed with 20% OPC, replaced with varying proportions of GGBS (10 - 40%) and Biochar (5 - 10%), and subjected to unconfined compressive strength (UCS) testing at various curing intervals (7, 14, & 28 days). Microstructural analyses (FE-SEM, FTIR, and XRD) were conducted to assess hydration products and matrix structure. Results show a 28.5% strength increase with 20% GGBS and a 68% increase with 10% biochar, compared to the traditional soil mix with 20% OPC, achieving peak UCS values of 1.0628 and 1.4021 N/mm², respectively, at 28 days.
