Present work focused on investigating the partial replacement of natural river sand (RS) by manufactured sand (MS) in concrete. The workability and mechanical properties like the density of hardened concrete, compressive strength, split tensile strength, and flexural strength of concrete mixtures made of MS and RS, were determined and compared. The experimental results show that the MS decreases the workability but improves the mechanical properties. In the present study, the compressive, split tensile, and flexural strength values have been calculated analytically with the ACI method besides experimentally. The model was also proposed for the compressive strength at the desired age and the percentage replacement of MS.Further, the effective utilization of MS was determined by multi-criteria decision-making techniques, namely analytical hierarchy process (AHP) and Techniques for order performance by similarity to ideal solution (TOPSIS). The result of AHP and TOPSIS were compared, and a comparison of these results shows that the effective utilization of MS is 25%. In addition the microstructure study also conducted to observed the change in bon behavior and the loss againgst to temperature by conducting XRD, FTIR and TG analysis. The cost analysis has been carried out for the analytically determined optimum mixture

Manufactured Sand, Entropy Method, TOPSIS, AHP