• 한국건축시공학회지
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• 제4권2호
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• pp.81-88
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• 2004

The purpose of this study is to investigate the chemical shrinkage and autogenous shrinkage of high strength cement paste and silica fume and fly ash and sand to cement ratio by the method of volumetric tests, and also investigate the autogenous shrinkage of high measurement method, and compare the results of volumetric test and linear length measurement test. A series of cement paste which have W/C ratio of 25%, 35%, 45% respectively were planed to study the effect of the W/C ratio to the shrinkages, and a series of cement paste which were replaced the cement by the silica fume and fly ash with 5%, 10%, 15% as the mass of cement respectively were planed to investigate the effects of poazolana to the shrinkages. A series of mortar which have a C/S ratio of 1:1, 1:1.5, 1:2 respectively were planed to investigate the shrinkage resistant effect of aggregate.

• Structural Engineering and Mechanics
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• 제51권3호
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• pp.403-412
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• 2014

In this paper, enhancement of corrosion and chloride resistance of high performance self compacting concrete (SCC) through incorporating nanosilica into the binder has been investigated. For this purpose, different mixtures were designed with different amounts of silica fume and nano silica admixtures. Different binder contents were also investigated to observe the binder content effect on the concrete properties. Corrosion behavior was evaluated by chloride penetration and resitivity tests. Water absorption and capillary absorption were also measured as other durability-related properties. The results showed that water absorption, capillary absorption and Cl ion percentage decreased rather significantly in the mixtures containing admixtures especially blend of silica fume and nano silica. By addition of the admixtures, resistivity of the SCC mixtures increased which can lead to reduction of corrosion probability.

• 한국건설순환자원학회논문집
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• 제2권1호
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• pp.66-73
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• 2014

Currently many researches have been performed for enhancing durability of concrete. Rice husk ash has several advantages like early strength of concrete and dense pore structure. A calcium silicate hydrate (CSH) gel around the cement particles due to pozzolanic reaction of rice husk can increase the strength of concrete against cracking. Very limitedly a systematic and detailed investigation on the corrosion performance of rice husk ash and silica fume blended concrete is performed. A realistic approach has been made through compressive strength, bond strength, and split tensile strength etc. Corrosion performance was also evaluated rapid chloride ion penetration test (RCPT) and impressed voltage test, and the results were discussed in the paper.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.775-780
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• 2003

The propose of this study is to discover concrete secondary products for proper mixing by lightweight concrete. The standard of water ratio 50% and weight substition 0%, 10%, 20% by Fly-ash. When produce manufactures, there use for maintain its form weight substition and addition among the viscosity agent each Silica-fume and Hydroxy propyl methyl cellulos. Testing method was to operate slump, air content, compressive strength test, rapid freezing and thawing test. The result of this study is appeared when substition Fly-ash generally it had better use Silica-fume.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2005년도 춘계 국제심포지엄 및 학술대회
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• pp.136-136
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• 2005

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.306-309
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• 2007

It shows not only positive effect with fan as a way of improving condition in workplace but also shows air supply, ventilation condition in welding site with CFD analyzation. Also when the wind blew to the front side by a fan, the welding Hume significantly reduced, As this was examined as CFD and was gone through enough exhaustion to become streamline flow laminar, the toxic materials will be reduced. The improvement of welding work and education are investigated to be more significant factors than wearing protective equipments and setting safety tools to prevent welding works from welding fume exposure.

• 한국농공학회논문집
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• 제47권6호
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• pp.27-34
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• 2005

The purpose of this study is to improve the durability performance of polymer modified cement composites for repair of concrete under combined aging conditions. The experimental procedure was divided into three parts. First, the replacement level of mineral admixtures in polymer modified cement composites were determined in an experimental study based on a Box Behnken design. Second, the flow value, compressive strength and chloride permeability test of sixteen types of mixtures were conducted. Test results show that the polymer modified cement composites were effected on the improvement of the compressive strength and permeability performance. Third, the effects on the replacement level of silica fume mixture was evaluated by the compressive strength, chloride permeability, chemical resistance and repeated freezing and thawing cycles test. They demonstrated that the polymer modified cement composites using mixture of silica fume, fly ash, and blast furnace slag improved the durability performance.

• 한국건축시공학회지
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• 제13권1호
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• pp.48-57
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• 2013

To consider the practicality and economic feasibility of developing reactive powder concrete (RPC), the strength and microstructure properties of RPC using ternary pozzolanic materials (silica fume, blast furnace slag, fly ash) were investigated in this study. Through the investigation, it was found that the compressive strength of RPC using ternary pozzolanic materials was increased significantly compared to that of the original RPC containing silica fume only. A considerable improvement in the flexural strength of RPC using ternary pozzolanic materials was found, and then the utilization of a structural member subjected to bending was expected. The X-ray diffractometer (XRD) analysis and Scanning Electronic Microscope (SEM) revealed that the microstructure of RPC was denser using the ternary pozzolanic materials than the original RPC.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.308-314
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• 1997

Shrinkage and creep are the fundamental properties of concrete. These long term deformations can be seen as bothersome(increased deflection) or can be seen as reduction of compressive stress of prestressed concrete. Steel fibers advance the mechanical properties of concrete:tensile strength, ductility, flexural strength, fracture toughness, and post-cracking resistance, etc...Silica fume is pozzolanic material which combines with hydrated lime to generate silicate materials which increase the compressive strength and reduce somewhat the creep of concrete. This paper is the result of the long-term deformation by silica fume and steel fibers with varying percentages.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.217-220
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• 2005

As this study is to test effects of sulfate attack on deterioration of concrete using in crushed aggregates. Besides tests have been carried out with concrete by river sand and crushed sand by fine sand, concrete mixes various proportions of slica fume and fly ash(up to 15$\%$ by weight fo cement) were prepared and immersed in pure water, sodium sulfate solution for 28 and 60days. Test on the change in the weight and compressive strength of concrete according to the duration of immersion time and the content of slica fume and fly ash was performed.