Once a nuisance waste product, silica fume is now a valuable addition to cement, creating concrete that is high strength, such as that used to build 311 South Wacker Drive, Chicago, once the worlds tallest reinforced-concrete building.
The company is the world’s best 95% Densified Silica Fume supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.
For more information, please visit Silica Fume for Refractories.
Silica fume is a by-product of the silicon metal/ferrosilicon alloy industry. Collected in baghouse filters, it is a very fine pozzolanic material. The addition of silica fume to concrete was first tested in Norway in the s. Although positive results were recorded in terms of improved strength, at that time no method of retaining large quantities of silica fume was available, preventing its industrial-scale use.
This changed in the s, when environmental regulations that required the removal of silica fume from exhaust gases were introduced. This led to significant improvements in filtration technology and, for the first time, the production of large amounts of silica fume.
Building on the earlier work of the s, intensive research was undertaken by Norwegian smelting companies to promote the use of silica fume. This work forms the basis for its use in concrete today.
The advantages of silica fume include significantly increasing concrete strength, a reduction in concrete bleeding and segregation (although this increases the need for proper curing), improved resistance to chemically-aggressive environments, and inhibition of alkali-silica reactions, which can severely damage concrete structures.
It is however a costly and difficult-to-handle material that requires special transportation and dosing equipment to avoid dust formation. It may also reduce resistance to carbonation, raising the risk of corrosion to carbon (black) steel reinforcement.
The very fine nature of silica fume particles (and thus its high surface area) brings both advantages and challenges. It develops strength far more quickly than other pozzolanic materials, allowing its use in the precast industry; however, it also results in a need for significantly more water in concrete production and the use of water-reducing admixtures.
For these reasons, cements containing silica fume are more rarely produced than those containing other pozzolanic industrial by-products, such as fly ash or natural pozzolans, its use being restricted to high-strength applications. For example, high-strength silica fume concrete was used in one of the worlds tallest reinforced-concrete buildings, 311 South Wacker Drive in Chicago, helping to significantly reduce the quantity of concrete and reinforcing steel that was required for construction.
Together with you, we hope to work on products that define an industry and try to make our world even better.
Founded in , HSA is a leading provider of Silica Fume in China, and also the premium source of high-performance Silica Fume products for concrete and refractory industries.
Sikacrete®-950 DP may be stored in bulk storage in a cement silo and be batched in the same manner as bulk cement. The 25 lb. bags of Sikacrete®-950 DP are repulpable or shredable bags, these bags are intended to be added directly to central or truck mixer without opening. The bags are designed to disintegrate through a combination of wetting and grinding the paper during concrete mixing. Specific batching and mixing instruction procedures for Central and truck mixing as outlined in the Silica Fume Association Users Manual and ASTM C94/C94M must be followed.
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Limitations: Do not introduce repulpable bags into concrete mixes with low watercementitious ratios and smaller size aggregates as these mixes may not develop sufficient mixing energy to fully repulp the bags. Always determine repulpability of bags by pretesting mix designs and batch sequence.
Please contact your local Sika representative for more information and assistance.
Compatibility with cement and other admixtures: Sikacrete®-950 DP is compatible with all known portland cements manufactured under ASTM specifications. The low water cement ratios typically specified for concrete containing microsilica make the use of a high range water reducer, such as a ViscoCrete® or Sikament® product essential in most applications. Sika® recommends the use of Sika® air entraining admixtures where air entrained concrete is required.
Workability and Finishing: Microsilica may affect the finishing characteristics of the concrete, particularly where warmer ambient conditions are encountered. The amount of bleed water from the concrete also may be reduced and Sika® recommends the use of a finishing aid and evaporation retarder such as SikaFilm® to aid finishing.
Together with you, we hope to work on products that define an industry and try to make our world even better.
Once a nuisance waste product, silica fume is now a valuable addition to cement, creating concrete that is high strength, such as that used to build 311 South Wacker Drive, Chicago, once the worlds tallest reinforced-concrete building.
For more information, please visit Silica Fume for Refractories.
Silica fume is a by-product of the silicon metal/ferrosilicon alloy industry. Collected in baghouse filters, it is a very fine pozzolanic material. The addition of silica fume to concrete was first tested in Norway in the s. Although positive results were recorded in terms of improved strength, at that time no method of retaining large quantities of silica fume was available, preventing its industrial-scale use.
This changed in the s, when environmental regulations that required the removal of silica fume from exhaust gases were introduced. This led to significant improvements in filtration technology and, for the first time, the production of large amounts of silica fume.
Building on the earlier work of the s, intensive research was undertaken by Norwegian smelting companies to promote the use of silica fume. This work forms the basis for its use in concrete today.
The advantages of silica fume include significantly increasing concrete strength, a reduction in concrete bleeding and segregation (although this increases the need for proper curing), improved resistance to chemically-aggressive environments, and inhibition of alkali-silica reactions, which can severely damage concrete structures.
It is however a costly and difficult-to-handle material that requires special transportation and dosing equipment to avoid dust formation. It may also reduce resistance to carbonation, raising the risk of corrosion to carbon (black) steel reinforcement.
The very fine nature of silica fume particles (and thus its high surface area) brings both advantages and challenges. It develops strength far more quickly than other pozzolanic materials, allowing its use in the precast industry; however, it also results in a need for significantly more water in concrete production and the use of water-reducing admixtures.
For these reasons, cements containing silica fume are more rarely produced than those containing other pozzolanic industrial by-products, such as fly ash or natural pozzolans, its use being restricted to high-strength applications. For example, high-strength silica fume concrete was used in one of the worlds tallest reinforced-concrete buildings, 311 South Wacker Drive in Chicago, helping to significantly reduce the quantity of concrete and reinforcing steel that was required for construction.
Together with you, we hope to work on products that define an industry and try to make our world even better.
Founded in , HSA is a leading provider of Silica Fume in China, and also the premium source of high-performance Silica Fume products for concrete and refractory industries.
Sikacrete®-950 DP may be stored in bulk storage in a cement silo and be batched in the same manner as bulk cement. The 25 lb. bags of Sikacrete®-950 DP are repulpable or shredable bags, these bags are intended to be added directly to central or truck mixer without opening. The bags are designed to disintegrate through a combination of wetting and grinding the paper during concrete mixing. Specific batching and mixing instruction procedures for Central and truck mixing as outlined in the Silica Fume Association Users Manual and ASTM C94/C94M must be followed.
Limitations: Do not introduce repulpable bags into concrete mixes with low watercementitious ratios and smaller size aggregates as these mixes may not develop sufficient mixing energy to fully repulp the bags. Always determine repulpability of bags by pretesting mix designs and batch sequence.
Please contact your local Sika representative for more information and assistance.
Compatibility with cement and other admixtures: Sikacrete®-950 DP is compatible with all known portland cements manufactured under ASTM specifications. The low water cement ratios typically specified for concrete containing microsilica make the use of a high range water reducer, such as a ViscoCrete® or Sikament® product essential in most applications. Sika® recommends the use of Sika® air entraining admixtures where air entrained concrete is required.
Workability and Finishing: Microsilica may affect the finishing characteristics of the concrete, particularly where warmer ambient conditions are encountered. The amount of bleed water from the concrete also may be reduced and Sika® recommends the use of a finishing aid and evaporation retarder such as SikaFilm® to aid finishing.
Together with you, we hope to work on products that define an industry and try to make our world even better.