• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.19-22
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• 1998

This study is investigate the properties of high performance concrete at W/B of 35%, used with silica fume and CSA expansive additives, which is used to improve the concrete qualities and prevent the drying-shrinkage. According to the results, the fluidity of concrete shows a decline with the increase of replacement percentage of silica fume and proportions of expansive additives. A higher strength is obtained at 5% of replacement percentage of silica fume, while the compensation achieves in drying-shrinkage of concrete at 5% of expansive additives.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.285-291
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• 1998

During recent years, the durability of concrete structures has been considered in concret practice and material research. To preserve the brittleness of concrete as well as energy absorption and impact resistance, amount of fiber usage has greatly increased in the field of public works. Ultra fine powder, silica fume, mixed into concrete, it reduce void of concrete structure. Especially, there's a great effect for strength improvement of concrete by initial pozzolanic reactions. For these reasons, if silica fume mixed into concrete, it decrease the total void by microfilter effect . Pozzolan reaction, between cement particle and silica powder, can elaborate the micro structure of matrix. And so, in this paper, we deal SFRC for the purpose of efficiently using of industrial by-products(silica fume). Also we performed the test for durability such as freeze-thaw resistance and accelerated carbonation of SFRC using silica fume.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.5
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• pp.87-92
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• 2010

This study set up 25, 35% for silica fume, SFFB's 2 level and water-combination material ratio, silica fume 10% for substitution ratio, and 4 level of SFFB 5, 10, 15(%) in order to compare and analyze the quality characteristic of ultra high strength concrete according to the substitution ratio of silica fume free binder (SFFB) that can be utilized as a substitute material for silica fume. As a result of an experimentation, the lower water-combination material ratio was, the higher addition ratio of high performance water-reducing agent for securing target liquidity increased, and it indicated the tendency that addition ratio of high performance water-reducing agent decreases because of material characteristic that SFFB has a lower absorptiveness than silica fume. The best strength was shown when SFFB substitution ratio is 10% at compressive strength and when substitution ratio is 15% at tensile strength, and it was indicated that at autogenous shrinkage contraction decreases compared to Plain(SF) regardless of substitution ratio of W/B and SFFB.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.180-186
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• 2005

This paper discusses the development of mixtures for silica fume as a stabilization/solidification agent and a binder for industrial wastewater residue containing organic and heavy metal contaminants. The UCS (unconfined compressive strength) gradually increased to 66.7% as the silica fume content increased to 15%. The leaching of TOC (total organic carbon) and chromium decreased as more OPC (Ordinary Portland Cement) was substituted with the silica fume. When a mixture had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution. Also, microstructural studies of the solidified analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contrilbute to setting but coated the cement particles and retarded the setting reactions. The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and the contaminant leachability.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.04a
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• pp.23-28
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• 1991

Silica-Fume, an industrial by product, has an extremely small average partical size of 0.1${\mu}{\textrm}{m}$ and when used as a concrete admixture fills the fine voids which exist in concrete. The purpose of this study is to investigate material properties of the high-strength concrete using Silica-Fume and Fly-Ash. The main variables studied are; a) water-cement ratio. b) Silica-Fume, Fly-Ash content. The maximum compressive strength of 1000Kg/$\textrm{cm}^2$ is achieved with a mix using 18% water-cement ratio, 20% Silica-Fume and 10% Fly-Ash ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.196-199
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• 2004

Metakaolin is a cementitious material for producing high-strength concrete. This material is now used as substitute for silica-fume. In this paper, we tested the compressive strength of concrete according to the substitute ratio of metakaolin, silica-fume. And we did the durability test such as chloride ion diffusion and chemical attack. In the compressive strength test, the result shows that $10\%$ substitute of metakaolin & silica-fume for binder is optimum. In the chloride ion diffusion test, according to the increase of substitute of metakaolin & silica-fume for binder, the diffusion coefficient is more reduced. And in the chemical attack test, according to the increase of substitute, the resistance is more excellent. In the durability test, we recognized that metakaolin is able to used as a substitute for silica-fume.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.443-448
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• 1999

Tests have been carried out on four concrete containing different levels of silica fume to measure their permeability coefficient using water and oxygen, chloride ion. The total cementitious content was 351kg/㎥, and the water/cementitious materials ratio was 0.55. The results show that a dramatic reduction in permeability of concrete containing silica fume occurs due to formation of a discontinuous macro-pore system which inhibits flow. Porosity estimates from mercury-intrusion porosimetry are used to develop an explanations for the water and air permeability reduction. And, results of the rapid permeability test showed that the resistance of concrete to the penetration of chloride ions increases significantly as a contents of silica-fume is increased. The current intensity passing through the concrete containing silica fume is presented from 664C to 2166C.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.1
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• pp.83-92
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• 1997

An experimental study of the application of Silica fume for the high strength concrete was conducted. Nine specimens with three different contents of silica fume, 0%, 10%, 20% and with three water-cement ratio 30%, 40%, 50% were tested. Results shows that 10% of silica fume and 30% of water-cement ratio has a maximum strength with 700kg/$cm^2$ of compressive strength and 64kg/$cm^2$ of splitting tensile strength and 100kg/$cm^2$ of flexural strength. Slump value of the tested samples decreases with increasing water-cement ratio and elapsed time of silica fume. Splitting tensile strength$({\sigma}_f)$ and flexural strength $({\sigma}_f)$ and static modulus of elasticity(E) can be correlated with compressive strength $({\sigma}_c)$ from a regression analysis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.185-186
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• 2023

In the production of high-strength concrete of 80 MPa or more, silica fume is widely used as a binder to ensure the strength safety and pumpability of concrete. The bulk density of silica fume is an important physical property that can have a significant impact on the performance of concrete. Therefore, Understanding the effect of silica fume density on the physical properties of concrete and selecting the appropriate material with the correct density is crucial to ensuring optimal performance in construction projects.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.107-108
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• 2010

This paper provides test results on the tension stiffening behavior of high strength concrete (HSC) members used silica fume free binder (SFFB) instead of silica fume. The objective of this study is to evaluate the capability of replacing expensive silica fume to SFFB in HSCs with compressive strength of 60 and 80MPa. Test results indicated that for two mixes of 60 and 80 MPa HSC, cracking and strength behavior of tension members, which are replaced silica fume to SFFB, showed equivalent performance to those of tension members used silica fume.