Sustainable Utilization of Waste Oyster Shell Powders with Different Fineness Levels in a Ternary Supplementary Cementitious Material System

As cement manufacturing accounts for 8% of global CO2 emissions, there is an urgent need to tackle the environmental impacts production and address decarbonization construction materials. Adopting supplementary cementitious materials (SCMs), including fly ash, slag, silica fume, etc., can be used as a partial replacement ordinary Portland (OPC) reduce emissions related OPC industry, while providing benefits waste valorization. This study aims explore sustainable utilization oyster shell powder (OSP)–lithium slag (LS)–ground granulated blast furnace (GGBFS) ternary SCM system in green concrete. The effect OSP fineness on compressive strength, hydration products, pore structure, transport properties SCM-based mortars was studied using wide array experimental techniques, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) analysis, Mercury intrusion porosimetry (MIP), water absorption test rapid chloride penetration (RCPT). results revealed that concrete with SCMs showed equivalent strength compared reference specimens. ion charge RCPT containing decreased by up 30% 81.4%, respectively. It observed specimens incorporating mesh size 3000 exhibited highest most refined microstructure.