The construction industry requires improved concrete performance through sustainable solutions. The present study investigates the synergistic effect of Glass Powder (GP) and silica slurry (SS) hybridization in self-compacting concrete (SCC) to improve the mechanical and microstructural properties. Fourteen SCC test mixes with varying proportions of GP (5-20%) as sand replacement and SS (2.5-7.5%) as cement replacement were studied. Results showed 15% GP improved flowability by 26% and 90-day compressive strength by 78.6%. The optimum mix (15% GP + 5% SS, w/c ratio = 0.36) showed 55% reduced water absorption, indicating enhanced durability. Microstructural examination showed a denser matrix, with BET analysis confirming reductions in surface area and pore volume by 75.5% and 67.2%. Despite enhanced early-age performance, ettringite formation in the interfacial transition zone was observed to limit long-term strength development. Hybrid use of GP and SS has been shown to enhance both the mechanical behavior and sustainability of SCC. |