• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.549-552
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• 2008

일반적으로 콘크리트의 공극수는 알칼리성이므로 철근의 부식이 방지된다. 그러나 염소이온이 침투하면 철근부식의 위험이 증가하게 된다. 특히 해양환경 콘크리트에서 염소이온의 공급이 활발하여 철근부식이 내구수명을 결정하는 중요한 인자가 되고 있다. 이 논문에서는 염소이온의 확산에 의한 이동을 고려하여, 해양환경에 노출된 사각형 콘크리트 교각에 대한 염소이온 침투해석을 수행하였다. 사각형 교각의 측면에 위치한 철근에 비하여 구석에 위치한 철근에 염소이온이 훨씬 빨리 축적됨을 확인하였다. 또 부식개시 임계농도에 도달하는데 걸리는 시간도 구석 철근의 위치가 측면 철근 보다 짧았다. 해석결과 임계 염소이온 농도에 걸리는 시간은 측면 철근에 비하여 절반 정도로 나타났으며, 따라서 사각형 교각의 염소이온에 대한 내구수명은 구석에 위치한 철근에 의해 결정되며 따라서 이차원 해석이 필요할 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.41-42
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• 2016

As the importance of maintenance of reinforced concrete structure recently has emerged, the attention of durability of structure has been increasing. There are many studies about durability decline especially due to the carbonation. In order to study carbonation progress after surface repair of carbonated concrete, each carbonation penetration velocity from different repair materials of concrete structure is compared through the experiment of carbonation accelerating CO₂ concentration to 20% and 100%. As carbonation infiltration progress is predicted through this study, the counterplan of service life evaluation will be prepared on selection of repair materials of concrete structure.

• Corrosion Science and Technology
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• 제14권2호
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• pp.99-105
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• 2015

The structures of reinforced concrete have been extensively increased with rapid development of industrial society. Futhermore, these reinforced concretes are easy to expose to severe corrosive environments such as seawater, contaminated water, acid rain and seashore etc.. Thus, corrosion problem of steel bar embedded in concrete is very important in terms of safety and economical point of view. In this study, specimens having six different coating thickness (W/C:0.5) were prepared and immersed in flowing seawater for five years to evaluate the effect of coating thickness and immersion time on corrosion property. The polarization characteristics of these embedded steel bars were investigated using electrochemical methods such as corrosion potential, anodic polarization curve, and impedance. At the 20-day immersion, the corrosion potentials exhibited increasingly nobler values with coating thickness. However, after 5-yr. immersion their values were shifted in the negative direction, and the relationship between corrosion potential and coating thickness was not shown. Although 5-yr. immersion lowered corrosion potential, 5-yr. immersion did not increase corrosion rate. In addition, after 5-yr. immersion, the thinner cover thickness, corrosion current density was decreased with thinning coating thickness. It is due to the fact that ease incorporation of water, dissolved oxygen and chloride ion into a steel surface caused corrosion and hence, leaded to the formation of corrosion product. The corrosion product plays the role as a corrosion barrier and increases polarization resistance. The corrosion probability evaluated depending on corrosion potential may not be a good method for predicting corrosion probability. Hence, the parameters including cover thickness and passed aged years as well as corrosion potential is suggested to be considered for better assessment of corrosion probability of reinforced steel exposed to partially or fully in marine environment for long years.