International Science Community Association Research Journal of Engineering Sciences 15 1 2026 01 26 Mechanical performance of M-30 Grade concrete incorporating Pyrogenic silica (silica fume) and Marble powder as partial Cement Replacements 8 15 EN Quipo June C. 1 College of Engineering, Nueva Vizcaya State University, Bayombong, Nueva Vizcaya, 3700, Philippines Jagtap Viplove Kumar 1 Department of Civil Engineering, Sushila Devi Bansal College of Engineering, Indore, MP, India Golghate Kavita 2 Department of Civil Engineering, Sushila Devi Bansal College of Engineering, Indore, MP, India Gupta Vikesh 3 Department of Applied Science & Humanities, Sushila Devi Bansal College of Engineering, Indore, MP, India > Research Paper 2026 1 4 2026 01 26 The extensive use of ordinary Portland cement (OPC) in concrete construction has raised serious environmental and cost-related concerns. This research investigates the performance of high-strength concrete incorporating Pyrogenic silica (silica fume) SiO2 and marble powder (CaCO3) as combined partial replacements for cement. Six Batches of M30-grade concrete mixtures were designed with OPC substitution levels ranging from 0% to 25%. Mechanical properties such as compressive strength, split tensile strength, and flexural strength were evaluated at 7, 14, and 28 days, along with workability characteristics. The results demonstrate that Pyrogenic silica (silica fume) SiO2 contributes to enhanced strength development through pozzolanic activity, whereas marble powder (CaCO3) improves microstructural compactness by acting as a filler material. An optimal replacement level of 15% SF and 5% MP achieved the highest strength enhancement, highlighting the effectiveness of SF–MP blends in producing sustainable and high-performance concrete. Copyright@ International Science Community Association