• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.517-520
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• 2008

In this study, corrosion resistance of steel in cracked-reinforced concrete was performed according to experimental method. Mixed design is OPC, 30% PFA, 60% GGBS and 10% SF, respectively. Moreover, corrosion resistance test was measured using ultra testing machine for 0.3mm crack induction. The corrosion resistance of blended concrete shows the results following OPC > 10%SF > 30% PFA > 60% GGBS after 60days curing. In case of mass loss test, embedded reinforcement in OPC concrete surveyed the minimum corrosion and appeared better corrosion resistance than blended concrete. As a result, corrosion resistance of sound concrete is higher than cracked concrete. Moreover, corrosion resistance of binary concrete is lower than OPC.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.375-381
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• 2017

Recently, due to the increasing of interest about the eco-friendly concrete, it is being increased to use concretes containing by-products of industry such as fly ash, ground granulated blast furnace slag, silica fume, and etc. Especially, these are well known for improving the resistance to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance to corrosion of reinforcement and critical chloride content of high volume fly ash concrete(HVFAC) which is replaced with fly ash for approximately 50% cement content. For this purpose, corrosion monitoring of reinforcement by half cell potential method was carried out for the cylindrical test specimens that the upper of reinforcement in concrete was exposed to detect the time of corrosion initiation for reinforcement. It was observed from the test result that the the time of corrosion initiation for reinforcement of HVFAC by the accelerated corrosion tests increased 1.2~1.3 times than plain concrete and the critical chloride contents of plain concrete and HVFAC were found to range $0.80{\sim}1.20kg/m^3$, $0.89{\sim}1.60kg/m^3$, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.559-568
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• 2019

Recently, the infrastructure of the marine environment has been increasing. Therefore, there has been increasing interest in increasing the durability of structures. The FRP Hybrid Bar with improved durability against corrosion was developed in recent years. On the other hand, studies that evaluate the corrosion resistance are insufficient. In this study, the corrosion resistance according to the type of rebar in concrete was assessed and analyzed. The experiment used steel bars and FRP Hybrid Bar. The corrosion test method was a galvanic current and half-cell potential method. The accelerated corrosion test was carried out by four levels (0%, 1.5%, 3%, and 6%) of chloride added to the concrete. The galvanic current measurements revealed no corrosion current in the FRP Hybrid Bar. The half-cell measurement also showed the corrosion resistance of the FRP Hybrid Bar. Therefore. FHB can be used as an alternative steel for structures where a marine environment and steel corrosion are predicted.

• Magazine of the Korea Concrete Institute
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• v.8 no.5
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• pp.201-209
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• 1996

Recently, large scale concrete structures exposed to severe environment are increasingly built in various locations. The corrosion may severely affect the durability and service life of such a concrete structure. It is, therefore, necessary to develop durable concrete to enhance the corrosion resistance. The corrosion resistance of concrete can be identified through accelerated corrosion test. The purpose of the present paper is, therefore, to devise a reasonable and accurate method to predict the amount of corrosion of reinforcing steels. The proposed method which is basically based on the concept of Faraday's Law, determines the corroded amount of a rebar according to accelerated corrosion time. The corrosion is accelerated by employing the potentiometric corrosion test arrangement. The effects of admixtures in concrete including fly ash and silica fume have been also studied to explore the relative corrosion resistance of concrete.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.1
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• pp.34-39
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• 2014

The purpose of this experimental research is to evaluate the resistance of reinforcement corrosion and chloride ion penetration of high volume fly ash (HVFA) concrete. For this purpose, concrete test specimens were made for various strength level and replacement ratio of fly ash, and then compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91 and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that compressive strength of HVFA concrete was decreased with increasing replacement ratio of fly ash but long-term resistance against reinforcement corrosion and chloride ion penetration of that was increased.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.289-290
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• 2009

In this study, the resistance of calcium aluminate cement (CAC) against chloride-induced corrosion was assessed by testing for the strength, chloride transport, and corrosion behaviour. The study found that the CAC concrete had better performance than ordinary Portalnd cement(OPC) in resisting the corrosion of steel.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.211-214
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• 1999

염화물 및 방청제가 함유된 철근 콘크리트의 부식특성을 마크로 셀 부식측정 방법인 갈바닉 전류 측정과 마이크로 셀 부식측정 방법인 선형분극 측정법 및 교류 임피던스법을 이용하여 염화물 및 방청제의 영향을 평가하였다. 마크로/마이크로 셀 부식측정기 Calcium Nitrite 방청제가 첨가된 시험체의 경우 갈바닉 전류 측정결과 낮은 전류값을 유지하였고, 교류 임피던스 측정결과 분극저항의 감소가 나타나지 않았으므로, 방청제의 첨가가 콘크리트내 철근의 부동태 피막을 보호하여 부식저항성을 향상시킴을 알 수 있었다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.10-17
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• 2016

Steel corrosion is a very significant problem both to durability and structural safety since reinforcement has to support loads in tensile region in RC(Reinforced Concrete) member. In the paper, newly invented FRP Hybrid Bar and normal steel are embedded in RC beam member, and ICM (Impressed Current Method) is adopted for corrosion acceleration. Utilizing the previous theory of Faraday's Law, corrosion amount is calculated and flexural tests are performed for RC beam with FRP Hybrid Bar and steel, respectively. Corrosion amount level of 4.9~7.8% is measured in normal RC member and the related reduction of flexural capacity is measured to be -25.4~-50.8%, however there are no significant reduction of flexural capacity and corrosion initiation in RC samples with FRP Hybrid Bar due to high resistance of epoxy-coated steel to corrosion initiation. In the accelerated corrosion test, excellent performance of anti-corrosion and bonding with concrete are evaluated but durability evaluation through long-term submerged test is required for actual utilization.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.217-223
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• 2005

This study is on the evaluation of three kinds of surface protectors for protecting reinforced concrete against corrosion of reinforcing steel by chloride attack and carbonation. In this study, the test has been carried out on the performance of specimens applied with surface protectors for anti-corrosion and anti-carbonation. The result showed that specimens applied with the three kinds of surface protectors, were excellent in resistance to the corrosion of reinforcing steel and carbonation. Especially the specimen applied with finish coating in conjunction with hydrophobic primer showed great reduction in the corrosion of reinforcing steel and carbonation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.214-221
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• 2024

The present study concerns the resistance of calcium aluminate cement (CAC) to steel corrosion. The corrosion behavior of steel, chloride binding/buffering and chloride transport were evaluated in order to predict the risk of steel corrosion. The CAC mortar exhibited no corrosion on steel, irrespective of the curing temperature and CAC types, whereas ordinary Portland cement (OPC) showed a severe corrosion on the steel surface. The chloride binding capacity of CAC found to be was lower than that of OPC, yet buffering capacity against pH decrease was found to be significantly higher in the CAC paste. Furthermore, chloride ingress at all depths was found to be reduced in CAC, thereby reducing the risk of corrosion.