Generally we use materials which are required for conventional concrete and addition to those we replace the low cost as well as light weight materials such as Fly-Ash. In this project we replace the cement to the fly ash and fine aggregate to the robosand by variable percentages. Fly ash is the by product of the combustion of pulverized coal in electric power generation plants. Fly ash particles are minute solid spheres. Fly ash is collected from the exhaust gases by electrostatic precipitators or bag filters Color generally ranges from dark grey to yellowish tan for fly ash used for concrete. Chemical makeup of fly ash is primarily silicate glass containing silica, alumina, iron, calcium. The perfect substitute for river sand is robosand. River sand is one of the basic ingredients in manufacture of concrete. River sand has become expensive and scarce. The crusher dust is known as Robosand can be used as alternative material to the river sand. Robosand possess similar propertiesas that of river sand, hence accepted as a building material. All replacements were done to the M30 grade of concrete.