A concrete use around the world is second only to water. The production of ordinary Portland cement contributes 5-7% of total greenhouse gas emission. It also consumes large amount energy. Hence it is essential to find the alternative to cement. Silica fume it is an ultrafine powder collected as a by-product of the silicon and ferrosilicon alloy production. It is also rich in silica and alumina. In this paper, silica fume is used to produce a geopolymer concrete. Geopolymer is a material resulting from the reaction of a source material that is rich in silica and alumina with the alkaline solution. Geopolymer concrete is totally cemented free concrete. In geopolymer, silica fume act as the binder and alkaline solution act as an activator. Silica fume and foundry sand are totally replaced and alkaline activator undergoes polymerization process to produce aluminosilicate gel. Alkaline solution used for present study is the combination of sodium hydroxide (NaOH) and sodium silicate (Na2Sio3) with ratio 3. A grade chosen for the investigation were M25.The mix was designed for molarity of 8M. Hot air curing is done by placing the specimens in the electric oven at 60ºC for the 24hours duration and 7days 14 days and 28days test is carried after heating. The geopolymer concrete specimens were tested for their compressive strength, flexure strength and split tensile test. Experimental investigations have been carried out on workability, the various mechanical properties of GPCs.