Sand plays a crucial role as an important component of concrete. Concrete is a widely used construction material. By examining the role of sand in enhancing workability, strength, and durability, we gain insight into its importance in shaping the structural integrity of concrete. Sand available in different Mohal of Barak Valley like Taranathpur river of Dwarbond, Katakhal river , Jatinga river, are found to be fail in zoning after Particle size Distribution Test . It is found to be fine to very fine in nature. So, for important Structure like multistorey buildings and bridges it does not give target strength in mix design. To achieve target strength, we have to mix crusher sand 5mm down with local sand subject to other property of sand ,cement and stone clips .This technique not only gives us target strength but saves cement 20-25% per cubic meter concrete. Crusher sand is easily available from stone crusher in this region.