The river sand and manufactured sand forms by the crushed rocks in millions of years. Nowadays, the reduction of river sand and manufactured sand is too fast in our environment because of our rapid construction world. So the GBFS (Granulated Blast Furnace Slag) is used at the place of river sand and manufactured sand but the presence of alkali and chloride in GBFS causes different problems like corrosion in reinforcement, react with external agents, high heat generated during the heat of hydration process and less durability. In this project, the foam separation method is adopted for removing the presence of alkali from GBFS (Granulated Blast Furnace Slag) and balance the pH value of crushed slag just like river sand and manufactured sand. The alkali and chloride remove from crushed slag in the form of bubbles and floats over the surface. The pH value balanced like river sand and manufactured sand. By using the foam separation method, 99% of alkali removed from GBFS (Granulated Blast Furnace Slag). The pH value of GBFS is balanced as equal to the river sand which is approx 7.00. The external effect of rainwater and chemical attacks are protected by removing the alkali from GBFS (Granulated Blast Furnace Slag). The total weight of construction also reduces because of the less value of bulk density of slag i.e. 1200kg/m³. After this method N-A-S-H OR C-A-S-H gel substituted by the C-S-H gel which is the same as well as river sand mix concrete. Also, protect our forest soil and area which places dumped by the Slag and its harmful to the soil nutrients and also for ecosystem.