the practical application of micro silica fume

The silica fume can fill the pores between the cement particles, meanwhile it can form a gel with the hydration product and react with the alkaline material magnesia to form a gel. In cement-based concrete, mortar and refractory castables, the addition of an appropriate amount of silica fume can play important roles in practical applications as following:

• Silica fume can significantly improve pressure resistance, flexural resistance, impermeability, corrosion resistance, impact resistance and wear resistance.
• Silica fume has the functions of retaining water, preventing segregation, bleeding and greatly reducing the pumping resistance.
• Silica fume can extend the life of the crucible significantly. In particular, under harsh environments such as chloride salt pollution, sulfate attack and high humidity, the durability of tantalum can be doubled or even multiplied.
• Micro silica fume can greatly reduce the floor ash of the spray raft and the castable, and the thickness of the single spray layer is increased.
• It is an essential component of high-strength concrete and has been applied to C150 concrete.
• It has about 5 times the efficiency of cement, also it can be used in common concrete and low cement castables to reduce costs and improve durability.
• It can prevent the occurrence of strontium aggregate reaction effectively.
• It can improve the compactness of the cast refractory. When coexisting with Al2O3, it is easier to form a mullite phase, which has high temperature strength and enhanced thermal shock resistance.
• Silica fume has a strong volcanic ash effect. When mixing concrete,m it can react with the cement hydration product Ca(OH)2 to form a gelation product, fill the cement stone structure, improve the micro structure of the slurry and improve the hardened body with mechanical properties and durability.
• Micro silica fume is an amorphous spherical particle that can improve the rheological properties of concrete.
• The micro silica fume has relatively small average particle size and a good filling effect and can be filled between the gaps of the cement particles to improve the strength and durability of the concrete.