Concrete is the most commonly used material by humans which stands next to the water in terms of consumption in the world. Due to the rapid growth in the construction sector, the amount of concrete to be used is increasing day by day which requires a huge quantity of natural materials such as river sand and aggregates. Due to the illegal sand mining and overexploitation, the availability of river sand is getting scarce day by day. The cement which acts as a binding material is one of the important materials in concrete. The most commonly used cement is Portland cement. For the generation of 1 ton of cement, approximately 1 ton of Co2 is released into the atmosphere. To overcome these problems, Supplementary cementitious materials to be used as a replacement for the cement. In this experimental work, fly ash and M Sand are used as a replacement to the cement and river sand. The strength properties such as compressive strength and tensile strength were compared with the conventional concrete of M25 grade with the concrete made by using replacement materials.