The document presents a comparative analysis of river sand, manufactured sand (M-sand), and quarry sand for use as fine aggregates in concrete. A series of tests were conducted to evaluate the compressive strength, split tensile strength, and flexural strength of concrete mixtures made with 100% replacement of river sand with M-sand and quarry sand. The results showed that at 28 days, M-sand concrete achieved higher strengths than river sand concrete, indicating that natural sand can be fully replaced with M-sand in concrete.