Concrete is the most widely used composite construction material. Fine aggregate plays a very important role for imparting better properties to concrete in its fresh and hardened state. Generally, river sand was used as fine aggregate for construction. Due to the continuous mining of sand from riverbed led to the depletion of river sand and it became a scarce material. Also, samining from river bed caused a lot of environmental issues. As a substitute to river sand, Robo sand has been used. In this present experimental study a comparative study has been carried out to check the usability of Robo sand in place of natural sand. This study involves determination of some major properties of concrete like compressive strength, split tensile strength, flexural tensile strength. Based on proposed studies, quality of Robo sand is equivalent to natural sand in many respects concrete is taken into account by taking its compressive strength, Split tensile strength and flexural strength values. The compressive strength, Split tensile strength and flexural strength value of the concrete made of Robo sand is observed to be very nearer to the strength of the concrete made of natural sand in the present investigation, there by 100% replacement is reasonable. As a substitute to river sand, Robo sand has been used.