Micro Silica is ultra fine amorphous (non-crystalline) polymorph of silicon dioxide. Because of its extreme fineness and high silica content, silica fume is a highly effective pozzolanic material. Silica fume is used in concrete to improve compressive strength, bond strength. It is highly resistive to impact, abrasion, heat and chemical attacks. It also reduces permeability; and therefore helps in protecting reinforcing steel from corrosion.