Influence of Silica Fume on Strength Characteristics of Fly Ash Alumino Silicate Concrete

caused pollution to the environment due to the emission of CO2. As such, alternative material had been introduced to replace OPC in the concrete. Fly ash is a by-product from the coal industry, which is widely available in the world. Moreover, the use of fly ash is environmental friendly and save cost compared to OPC. Fly ash is rich in silicate and alumina, hence it reacts with alkaline solution to produce alumina silicate gel that binds the aggregate to produce a good concrete. The compressive strength increases with the increasing of fly ash fineness and thus the reduction in porosity can be obtained. Fly ash based geo polymer also provided better resistance against aggressive environment and elevated temperature compared to normal concrete. In this present investigation the strength properties of different concentration of molarity of fly ash- geo polymer concrete by partially replacing fly ash by Silica fume was studied. It is concluded that higher concentration of molarity and a partial replacement of silica fume to the f ly ash increases the Compressive Strength and Tensile strength of geo polymer concrete. Index terms- Fly ash, silica fume, geo polymer, alkaline solution, Compressive strength, Tensile strength I