• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.183-188
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• 1996

The durability of concrete structures decrease due to deterioration of concrete when they are constructed in marine or pollutional environments. In this study, the mortar specimens made from the five different types of cement were immersed in artificial seawater and four kinds chemical solution, and were measured the change of compressive strength and weight. The results show that the longer the immersed days are, the more the compressive strength reduction is. It has been remarked that the resistance of slag cement and ground granulated blast-furnace slag is excellent in chemical attack.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.527-530
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• 2005

Shotcrete have become a deterioration which is used in the underground such as groundwater and soil in sulfate ion. Sulfate attack on concrete structures in service is not widespread, and the amount of laboratory-based research seems. to be disproportionately large. In this study, immersion test using $Na_2SO_4$ solution($1,2,5\%$) was performed to evalute the resistance of shotcrete. From the results of the immersion test for 112 days of exposure. In order to understand the deterioration mechanism due to seawater attack, test using scanning electron microscopy(SEM) analysis and X-ray diffraction showed that the deterioration mechanism due to sulfate attack in shotcrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1989년도 가을 학술발표회 논문집
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• pp.25-30
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• 1989

In this paper, morter and concrete specimens made with four cements were immersed in Mgcl2, MgSO4 Solution and artifical Seawater which was corresponded with Seawater. The hydration products of immersed cement pastes were looked over by using SEM, EDS and X-ray diffraction method. The results show that the concrete made with domestic flyash cement and blast-frrnace slag cement is superior to that of ordinary portland cement in resistance to chloride and sulphate solution. Especially, it is found that the attack of Cl-ion on the concrete plays an important role of the deterioration of concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.51-56
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• 2002

Protection against salt attack in seawater is obtained by using a dense, quality concrete with a low water-cement ratio, and a components appropriate for producing concrete having the needed salt resistance. The objective of this study is to evaluate the feature of corrosion with using the various concrete materials under marine exposure environment. According to the test results, slag powder and anti -corrosion inhibitor showed high chloride resistance effect. Also concre crack have an influence on corrosion of steel in spite of mixed design for salt resistance concrete. The requirement for low permeability is essential not only to delay the effect of salt attack, but also to afford adquate protection to reinforcement with admixtures.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.169-172
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• 2006

The IIA structures exposed to marine environment is subject to many different types of potential attack. The physical attack due to drying and wetting would increase the internal stress of concrete. The chemical attack resulting from the diffusion of ions$(Cl^-,SO_4^{2-},Mg^+)$ from seawater through the pores in concrete. Therefore the sea water resistance of concrete must be considered when it is used for structure in the ocean. The objective of this study is to evaluate chloride diffusion and corrosion characteristics of concrete when using the various concrete materials under marine environment. After 5 years of exposure, concrete incorporating 40% blast-furnace slag as replacement for type I cement with low w/c ratio of 0.42 and using the inhibitor shows excellent performance.

• Corrosion Science and Technology
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• 제17권4호
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• pp.176-182
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• 2018

Corrosion of the Cu alloy with 10wt% Ni in stagnant seawater with residual free chlorine was investigated. Despite that fact that Cu alloys are widely used for seawater applications due to their stubborn resistance to chloride attack, not much is known as to how the residual free chlorine in seawater affects corrosion of Cu and its alloys. In this work, immersion tests were conducted in the presence of different levels of chlorine for 90-10 Cu-Ni samples, one of the most frequently used Cu alloys for seawater application, mostly in shipbuilding. The results revealed no evidence for accelerated corrosion of the Cu-Ni alloy even in the presence of 5 ppm residual chlorine in seawater, signifying that the Cu-Ni alloy can be more tolerant to residual chlorine that has been commonly cited by the shipbuilding industry. However, comparison of polarization behavior of the alloy samples in the presence of different electrolytes with different concentrations of residual chlorine suggests that higher concentration of chlorine could increase the corrosion rate of the Cu-Ni alloy. Furthermore, it is suggested that microorganisms in the seawater could increase the corrosion rate of the Cu-Ni alloy by encouraging exfoliation of the corrosion product off the metal surface.

• 콘크리트학회논문집
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• 제23권1호
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• pp.23-30
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• 2011

이 연구는 콘크리트의 내구성 저하요인인 해수침식 및 동결융해 반복작용을 받은 콘크리트의 성능저하 정도를 실험적으로 고찰하기 위하여 포틀랜드 및 혼합시멘트를 사용하여 콘크리트 공시체를 제조한 후 상대동탄성계수, 압축강도 변화 및 기기분석을 통하여 성능저하 원인을 구명하였다. 동결융해 520싸이클까지의 결과 보통포틀랜드 및 저열포틀랜드시멘트는 75% 이상의 상대동탄성계수와 압축강도가 내황산염포틀랜드시멘트 약 44%의 값을 나타내어 상대적으로 낮은 저항성을 나타내었으며, 고로슬래그미분말을 50% 대체하여 사용한 콘크리트가 혼합시멘트계 콘크리트 중 가장 우수한 동결융해 저항성을 나타내었다. 혼합시멘트계 콘크리트의 해수침식 유 무에 따라 비교한 결과, 고로슬래그미분말 콘크리트의 잠재수경성 촉진으로 동결융해 저항성이 우수하였으나, 실리카퓸을 혼합한 콘크리트는 해수침식에 의한 성능저하가 발생하여 동결융해 저항성이 낮아지는 경향을 나타내었고, 해수침식 및 동결융해 작용을 받은 보통포틀랜드 콘크리트는 동결융해 작용에 의한 쏘마싸이트 피크와 해수침식에 의한 석고 및 프리델 염분 피크가 주로 검출되고, 고로슬래그미분말을 혼합한 콘크리트는 해수침식의 유 무에 상관없이 좋은 결과를 나타내었다.

• 한국표면공학회지
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• 제51권2호
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• pp.87-94
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• 2018

Various sealing techniques were applied to the anodized 5083 aluminum alloy for marine environment to reduce corrosion and cavitation erosion damage. Electrochemical experiments and cavitation erosion tests were conducted to evaluate the corrosion resistance and cavitation resistance of the anodic oxide film treated with sealing in natural seawater solution. Then, damaged surface morphology was analyzed by scanning electron microscope(SEM) and 3D microscope. As the results of the electrochemical experiments, it was observed that the surface damage of all the experimental conditions in the anodic polarization experiment was locally grown by the combination of crack and corrosion damage. In the Tafel analysis, the corrosion resistance of all sealing treatment conditions was improved compared to the anodizing. On the other hand, cavitation erosion tests showed that the anodizing and all the sealing treatment conditions generated local pit damage by cavitation erosion attack and grew to crater damage in the observation of damaged surface by SEM. Also, the weight loss and the surface damage depth measured with the experiment time presented that most of the sealing treatment conditions showed better cavitation erosion resistance than the anodizing, and they had an incubation period at the beginning of the experiment.

• 한국건설순환자원학회논문집
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• 제5권2호
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• pp.152-159
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• 2017

해양환경에서 콘크리트의 내구성과 철근의 부식은 콘크리트 내부로 침투하는 염소이온에 의해 악화된다. 본 연구에서는 염소이온에 의해 야기되는 콘크리트의 염해부식에 대한 저항성을 향상시키기 위해 전도성 광촉매를 사용하였다. 시험체로는 전도성 활성탄소와 광촉매($TiO_2$)분말을 혼합하여 모르타르와 콘크리트를 제작하였다. 전도성 탄소의 함량이 증가할수록 압축강도는 감소하였다. 전도성 광촉매가 첨가된 시험체가 일반 시험체보다 월등히 우수한 내염해부식성을 나타내었으며 이것은 XRF 시험에 의한 분석 결과 모르타르 또는 콘크리트 내부로의 염소이온 확산이 광촉매 작용에 의해 억제되었기 때문인 것으로 판단되었다. 모르타르 및 콘크리트 내부로의 염소이온 확산계수를 구함으로써 광촉매에 의한 염소이온 확산에 대한 억제반응이 분석되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.676-681
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• 2000

This paper covers durability and field application of marine concrete which have been enhanced the resistance against deterioration in seawater. Fly ash concrete is applied to make the concrete with good durability. It is well known fly ash in concrete has a good performance preventing fro a sulphate attack and a steel corrosion. Several durability tests were performed to find characteristics of marine concrete which is proposed in this paper comparing with normal concrete. Field application was executed to compare results with laboratory test and to give a reliability to engineers. The project was supported by Ministry of Marine Affairs and Fisheries for two years.