From Laboratory Waste to Building Strength: Evaluating Borosilicate Glass Powder as a Cement Replacement

Abstract The cement industry’s contribution of approximately 8% to global carbon dioxide ( CO 2 ) emissions, coupled with significant laboratory glass waste disposal challenges, necessitates sustainable solutions addressing both environmental concerns. Despite extensive research on supplementary cementitious materials (SCMs), limited investigation exists on borosilicate glass powder (BSGP) as cement replacement, representing a critical research gap in sustainable construction materials. This study aims to investigate BSGP as a sustainable cement replacement in mortar systems, evaluating its effects on mechanical properties, durability performance, and environmental sustainability. BSGP was incorporated at 10%, 15%, 20%, and 25% cement replacement levels with comprehensive 120-day evaluation encompassing mechanical property testing, durability assessments (electrical resistivity, water absorption, acid resistance), microstructural analysis, predictive modeling, and life cycle assessment (LCA). The 15% BSGP replacement achieved optimal performance with 8.91% higher compressive strength (63.56 MPa) and 7.71% improved splitting tensile strength compared to control specimens. Durability enhancements included 91.37% increased electrical resistivity, 16.92% reduced water absorption, and superior acid resistance with 10% less strength degradation. The predictive model demonstrated 91% accuracy ( R 2 = 0.925 ), whereas life cycle assessment revealed linear reductions of 32.9 MJ / m 3 embodied energy (EE) and 6.43 kg CO 2 - eq / m 3 global warming potential (GWP) per 1% replacement. BSGP at 15%–20% replacement effectively enhances mechanical performance and durability while reducing environmental impacts; however, performance declines at 25% due to excessive cement dilution, confirming dosage-dependent effectiveness and alignment with circular economy principles.