Silica fume

Shankersinh Vaghela Bapu Institute of TechnologyConcrete technology

Topic : Silica Fume

Prepared By : Vijay Patel Guided By: Prof. Ankit PatelEn No : 130750106081Silica fumeSilica fume is a product resulting from reduction of high purity quartz with coal is an electric arc furnace in the production of silicon or ferrosilicon alloy.it is also referred to as micro silica or condensed fume .It is an artificial pozzolanic material.Silica fume rises as an oxidised vapour.it cools, condensed and is collected in cloth bags. Condensed silica fume contains more 90% of silicon dioxide in non crystalline form.

Silica fume is more efficient in concrete having high water-cement ratio.It has been found that concrete with a water-cement ratio of about 0.55 and higher ,the silica fume has an efficiency factor of 3 to 4. It means that 1kg of silica fume can replace 3 to 4 kg of cement in concreteThe usual percentage replacement is 0-10 % . In India the silica fume of international quality is marketed by: Elkem metallurgy (p) Ltd., 66/67, Mahavir Center, Sector 17, vashi, Navi Mumbai 400703. Recently, Steel Authority of India has provided necessary facilities to produce annually about 3000 tons of silica fume at their Bhadravati Complex. Silica fume concrete was first used in India by Nuclear Power Corporation in their Kaiga and Kota Nuclear Power Project.Silica fume concrete has been used for the construction of Bandra-Worli sea project. (b) Silica fume in the concrete can be used for the following purposes:To conserve cement.To produce ultra high strength of the order of 70 to 120Mpa.To increase early strength of fly ash/slag concrete.To control alkali-aggregate reaction.To reduce sulphate attack and chloride associated corrosion.

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