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Concrete is the most widely consumed construction material after water. Increasing environmental concerns related to greenhouse gas emissions from the cement industry necessitate the use of waste products and alternative minerals as partial cement replacements. This study investigates the strength properties of M30 grade self-curing concrete using Magnetite (Fe3O4) as a partial replacement for Ordinary Portland Cement (OPC) at 5% and 7.5% by weight, combined with Super Absorbent Polymer (SAP) – sodium polyacrylate (0.25% by weight of cement) – as an internal self-curing agent. Compressive strength, split tensile strength, and flexural strength tests were conducted on cube and cylinder specimens at 7 and 28 days. Results show that 7.5% Fe3O4 replacement achieves the highest compressive strength, while 5% Fe3O4 with 0.25% SAP yields superior long-term flexural performance. The SAP effectively retained internal moisture, reducing bleeding and segregation, and improving workability.