Silica fume in 5 main function 1, the control of concrete materials, segregation and bleeding, reduce or avoid the emergence of concrete cellular, Ma face, weak interlayer, skin defects such as cracks and milk. 2 and improve the compressive strength of concrete, experimental proof of silica powder can greatly increase the strength of concrete. 3, to improve the durability of concrete to improve concrete's impermeability, frost resistance, abrasion resistance and corrosion resistance of 4 to improve the anti-carbonization of concrete for the reinforced concrete, mixed with silica powder can increase inequality between the matrix and the reinforcement The bond strength, but also enhance the capacity of steel resistance to corrosion. 5, to improve the mobility and dense refractories increased the levels of refractory high-temperature strength and thermal shock resistance.