• Title/Summary/Keyword: Reinforcing Corrosion

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A Study of Non-destructive Measurement on the Reinforced Concrete Structure Damaged by Reinforcing Steel Corrosion (철근콘크리트구조물의 철근부식에 대한 비파괴 측정과 부식에 따른 균열거동)

  • 김성운;정한중;김창환;임선택
    • Proceedings of the Korea Concrete Institute Conference
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    • 1991.10a
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    • pp.80-85
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    • 1991
  • This experimental study was performed to derive the relationship between the measured values(corrosion potential) and the actual amount of corrosion products(reinforcing steel weight loss rate). Also the growth of crack due to the steel corrosion was oberved. First, the reinforcing steel of R/C specimen was corroded with chloride penetration and accelerated galvanostatic corrosion method. And then, the corrosion potential of reinforcing steel was measured with nondestructive tester.

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A comparative study on bond of different grade reinforcing steels in concrete under accelerated corrosion

  • Kurklu, G.;Baspinar, M.S.;Ergun, A.
    • Steel and Composite Structures
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    • v.14 no.3
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    • pp.229-242
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    • 2013
  • Corrosion is important reason for the deterioration of the bond between reinforcing steel and the surrounding concrete. Corrosion of the steel mainly depends on its microstructure. Smooth S220, ribbed S420 and S500 grade reinforcing steels were used in the experiments. Samples were subjected to accelerated corrosion. Pullout tests were carried out to evaluate the effects of corrosion on bond strength of the specimens. S500 grade steel which has tempered martensite microstructure showed lower corrosion rate in concrete than S220 and S420 steels which have ferrite+perlite microstructure. S500 grade steel showed highest bond strength among the other steel grades in concrete. Bond strength between reinforcing steel and concrete increased with increase in the strength of steel and concrete. It also depends on whether reinforcing bar is ribbed or not.

An Experimental Study on the Corrosion Protection Method of Reinforcing Steel in Concrete by Using Corrosion Inhibitor (방청제에 의한 콘크리트 내의 철근 방식법에 관한 실험적 연구)

  • 배수호;정영수;권영우;김년산;권혁진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.710-713
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    • 2000
  • The corrosion protection methods of reinforcing steel in concrete are the various methods such as increasing thickness of cover concrete, using of reinforcing bars coated with epoxy, dosage of corrosion inhibitor as concrete admixture, cathodic protection method and etc. The most economical method of them will be the corrosion protection method using corrosion inhibitor as concrete admixture. Therefore, the purpose of this research is to investigate the performance of corrosion protection of ordinary strength and high strength concrete using corrosion inhibitor, respectively. For this purpose, after manufacturing ordinary strength and high strength concrete with and without corrosion inhibitor, the accelerated corrosion tests for reinforcing steel were conducted according to the periodic cycles (140 day) of wetting ($65^{\circ}C$, 90% R.H.) and drying period ($15^{\circ}C$, 65% R.H.). As a result, th high strength concrete using corrosion inhibitor showed an excellent performance of corrosion protection.

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The Application of Impressed Current System for the Corrosion Control of Reinforcing Steel in Concrete (콘크리트 중의 철근부식 방지를 위한 외부전원법의 적용)

  • 문한영;김성수;김홍삼
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.197-202
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    • 1997
  • Recently the interest in the reinforcing steel corrosion due to the use of sea-sand and deicing salt, marine environment, and carbonation in RC structures is increasing, therefore the studies on the corrosion control of reinforcing steel in concrete are vigorously proceeding. In this study, from the viewpoint of electrochemical process of steel corrosion in concrete we applied the impressed current system among the cathodic protections to reinforcing steel in concrete and ascertained the protection effect by half-cell potential, corrosion rate, and depolarization.

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Corrosion Protection Method of Reinforcing Steel in Concrete by Using Corrosion Inhibitors

  • Bae Su-Ho;Chung Young-Soo;Kim Dae-Ho
    • KCI Concrete Journal
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    • v.14 no.4
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    • pp.145-150
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    • 2002
  • Reinforced concrete is inherently a durable composite material. When properly designed for the environment to be exposed and carefully constructed, reinforced concrete is capable of giving maintenance-free performance. However, unintentionally using improper materials such as non-washed sea sand having much salt together with poor controlled quality, or the concrete are placed in highly severe environment such as marine atmosphere, the corrosion of reinforcing steel in concrete becomes one of the most significant concerns of concrete. The purpose of this experimental research is to evaluate the performance of corrosion inhibitors for normal strength and high strength concrete, and to propose desirable measures for controlling corrosion of reinforcing steel in concrete. Test specimens in normal strength and high strength concrete were made with and without corrosion inhibitors. The accelerated corrosion test for reinforcing steel in concrete was adopted in accordance with JCI-SC3, which required the periodic 20 cycles for 140 days. One cycle includes 3 days for the wetting condition of $65^{\circ}C$ and $90\%$ RH, and 4 days for the drying condition of $15^{\circ}C\;and\;60\%$ RH. It was observed from the test that corrosion inhibitors in normal strength concrete and high strength concrete showed excellent corrosion resistance for reinforcing steel in concrete, but the silica fume in high strength concrete was found to have a negligible corrosion resistance if not used with corrosion inhibitors, since the chloride corrosion threshold limit in concrete containing silica fume without corrosion inhibitor was found to be considerably smaller than that of the case with corrosion inhibitor.

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An Experimental Study on the Corrosion Characteristics of Reinforcing Steel in Concrete by the Accelerated Corrosion Test (부식촉진시험에 의한 콘크리트 내의 철근의 부식특성에 관한 실험적 연구)

  • 배수호;정영수;김년산;권영우;권혁진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.503-507
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    • 2000
  • The corrosion protection methods of reinforcing steel in concrete are the various methods such as increasing thickness of cover concrete, using of reinforcing bars coated with epoxy, dosage of corrosion inhibitor as concrete admixture, cathodic protection method and etc. In this study, the performance of corrosion protection was investigated for the test specimens using corrosion inhibitors and cathodic protection, respectively. For this purpose, the accelerated corrosion tests for reinforcing steel were conducted according to the periodic cycles(140 days) of wetting($65^{\circ}C$, 90% R.H) and drying period($15^{\circ}C$, 65% R.H) for the test specimens. As a result, it can be concluded from the test that the effect of corrosion inhibitor was found to be variable with products, the cathodic protection method was found to be independent of salt concentration in concrete.

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An Experimental Study on the Corrosion Monitoring of Reinforcing Steel in Concrete by the Accelerated Corrosion Test (부식촉진시험에 의한 콘크리트 내의 철근의 부식 모니터링에 관한 실험적 연구)

  • 배수호;정영수;김진영
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.543-548
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    • 2001
  • The corrosion monitoring methods of reinforcing steel in concrete are the various methods such as half cell potential method, galvanic current method, resistivity method, polarization resistance method, AC impedance method and etc. In this study, the corrosion monitoring methods of reinforcing steel in concrete were investigated for the test specimens using corrosion inhibitors, zinc-mortar, zinc-plate, respectively. For this purpose, the accelerated corrosion tests for reinforcing steel were conducted according to the periodic cycles(140 days) of wetting($65^{\circ}C$, 90% R.H.) and drying period(15$^{\circ}C$ , 65% R.H.) for the test specimens. As a result, it can be concluded from the test that half cell potential and galvanic current method as monitoring techniques for corrosion were found to be relatively reliable and easily usable method in the field.

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A Study on the Reinforcing Bar Corrosion Caused by Permeation of Chloride Ion Under Sustained Load (지속 하중하에서 철근콘크리트 부재의 염화물 침투특성에 따른 철근부식에 관한 연구)

  • 최일호;김형래;윤상천;지남용
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.779-782
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    • 1999
  • This study was carried out to estimate the effects of the loading conditions on the corrosion of reinforcing bars and permeation of chloride ion. The permeation of chlorides depends not only on the transfer properties in concrete but also on the load applied in the case of reinforced concrete structures. Recent studies reported that the loading conditions affected the corrosion rate of the reinforcing bars under existence of an external current supply. But it was not reported that loading conditions affected corrosion of reinforcing bar caused by the characteristics of permeation and the process of cracking. In this experiment, it was shown that the corrosion of reinforcing bars and the characteristics of permeating were greatly affected by the loading conditions.

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A Fundamental Study on the Method Repair for Crack in Concrete by Corrosion of Steel Reinforcing (콘크리트 내부 균열에 대한 보수기법의 기초적 연구)

  • Lim, Nam-Gi;Paik, Min-Su;Kwon, Young-Jin;Choi, Eung-Kyoo;Chung, Lan;Jung, Sang-Jin;Choi, Mun-Shik
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.579-584
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    • 1997
  • This experimentation is to apperciation an efficiency of repair for processing crack by corrosion of steel reinforcing, Crack on concrete by corrosion of steel reinforcing is the fact that the first crack appear on the surface of water because of supplying is of oxygen and water. The crack processing is on surface to be contacted by air and to bottom as mainly the vertical direction from a surface of water. The experimentation gives rise to crack in model by electricity. Crack by corrosion of steel reinforcing is more internal crack than external crack. since it is so. crack by corrosion of steel reinforcing have to attention to repair or intermal crack.

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Repid Corrosion Test on Reinforcing Steels in Chloride-Penetrating Concrete Structures with Various Crack Patterns (균열특성에 따른 콘크리트 구조물의 염분침투에 관한 실험적 연구)

  • 이상국;정영수;문홍식;안태송;유환구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.345-350
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    • 2001
  • Reinforced concrete is, in general, known as a high durability material due to a strong alkalinity of cement. Probable concrete cracks could incur steel corrosion of RC structures and then could easily deteriorate the concrete durability, which can be fully secured by a systematic quality control for the construction of concrete structures. For the corrosion protection of reinforcing steels in concrete, however, current design specifications of concrete cover depth do not in-depth consider the effect of the cracks as well as the chloride content of RC structures. Therefore, appropriate provisions for concrete cover depth should be coded by considering the influence of concrete cracks on the corrosion of reinforcing steels. The objective of this research is to investigate pertinent cover depth, which can prohibit rebar corrosion, on the basis of experimental corrosion measurements of reinforcing steels on crack characteristics such as the width, depth and frequency of concrete cracks.

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