• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.254-257
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• 2006

Five bench scale specimens were used to evaluate corrosion performance of damaged epoxy-coated bars in chloride contaminated concrete. The test specimens were subjected 48 weekly cycles of ponding with sodium chloride solution and drying. Test results using linear polarization technique show that the current density of specimen with conventional steel becomes $0.715\;{\mu}A/cm^2$ indicating that the steel bars are in moderate or high corrosion condition. However, the corrosion rates of the specimens with damaged epoxy coated bars are much below $0.1\;{\mu}A/cm^2$ and the bars appears to be in passive condition. The corrosion protection performance provided by calcium nitrite is better than that of specimens with the other two inhibitors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.165-168
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• 2006

The major cause of deterioration for the bare concrete bridge decks exposed to de-icing chemicals would be chloride-induced reinforcement corrosion. Thus, in this paper, in order to predict time to corrode for concrete bridge decks on highways, the chloride concentration was measured with depth from the surface. Then, the surface chloride concentration and apparent diffusion coefficient were calculated by regression. The premature failure of bare concrete decks were mostly related with thin cover depth and poor concrete property(high permeability). The good protection of deck surface might contribute to the prolongation of the service life of bare concrete bridge decks.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.399-400
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• 2009

본 연구에서는 염화물 이온을 효율적으로 침투방지 시키기 위한 방법으로, 나노실리카를 이용한 해양콘크리트 방식공법의 현장 적용성에 대하여 검토하였다. 적용결과, 굳지않은 콘크리트에서는 슬럼프 및 공기량에서 큰 차이가 없는 것으로 나타났고, 경화 콘크리트의 염화물 확산 특성에서는 초기 및 후기에서 공히 우수한 효과가 있는 것으로 나타났는데, 이는 나노실리카가 염소이온의 침투 및 확산을 방지하였기 때문인 것으로 판단된다.

• International Journal of Concrete Structures and Materials
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• 제8권3호
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• pp.201-212
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• 2014

Sixteen reinforced concrete laboratory specimens were used to evaluate a number of corrosion prevention methods under an accelerated (6 months) testing program. The use of galvanic thermal sprayed zinc, galvanic embedded anodes, a tri-silane sealer, an acrylic coating, and an epoxy/polyurethane coating was evaluated. The specimens received various treatments prior to exposure to accelerated corrosion. The performance of the treatments was evaluated with respect to corrosion currents, chloride ingress, extent of cracking, severity of rust staining, and visual inspection of the reinforcing steel after the conclusion of testing and dissection. Results indicated that the tri-silane sealer, the conjoint use of galvanic thermal sprayed zinc and epoxy/polyurethane coating, the epoxy/polyurethane coating, and acrylic coating performed better than the other methods tested. Higher chloride concentrations were measured in the vicinity of embedded zinc anodes.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.519-522
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• 2005

Ka-Hwa highway bridge, located in a corrosive marine environment, had been examined the current condition of reinforcement corrosion in concrete throughout half-cell potentials, electrical resistivity, chloride contamination of concrete, and visual observation. According to the test, the chloride corrosion reinforced concrete structure is not only the protecting film around the reinforcement is deteriorated but also corrosion activity develops, for example, delamination areas of concrete. The purpose of this paper is to report the effects of Ka-Hwa highway bridge damaged by chlodide attack and to present the results of repair of Ka-Hwa highway concrete bridge in domestic marine environment.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.91-94
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• 2007

It is essential every concrete structure should continue to perform its intended functions, that is maintain its required strength and durability, during the service life. However, deterioration occurs more progressively from the outside of concrete exposed to severe conditions. Deterioration in the concrete structure is due to carbonation and chloride ion attack. Therefore, concrete structure is needed to surface protection for increase durability using impregnant. Impregnant classify into two large groups in polymeric and silicate materials. Silicate impregnant is included silane and alkali silicate(sodium and lithium silicate). Thus, this study is concerned with carbonation and chloride ion resistance of self cleaning hydrophilic impregnant of concrete structure using lithium and potassium silicate. From the experimental test result, lithium and potassium silicate have a good properties as a carbonation and chloride ion resistance. Lithium and potassium silicate make good use of hydrophilic impregnant.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.203-204
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• 2023

Recycled aggregate is an aggregate that satisfies the quality as an aggregate by crushing waste concrete and passing it through a separator. The government grants a floor area ratio of up to 15% and building height mitigation when more than 25% of the recycled building materials are used. In addition to environmental protection issues, it is necessary to actively utilize recycled aggregates that meet the standards to secure the business feasibility of buildings. This study attempted to derive the results according to the substitution rate by measuring the chloride ion diffusion characteristics based on the electrophoresis method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.207-212
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• 1996

Recently, massive concrete structures exposed to salt from ocean marine environments, or from winter deicing. The corrosion caused by chloride-penetration may affect severey the durability and service life of such a concretestructures. Thus, it is necessary to develop durable concrete to enhance the corrosion resistance. In this study, we investigate the usage of adequate corrosion-protection materials in order to reduce permability-coefficient of concrete and method of enhancing the durability of concrete structures using by penetrating corrosion-protection materials.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.1065-1068
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• 2008

해상교량은 바다에 노출되기 때문에 많은 경우 본래의 설계수명을 다하지 못하고 조기에 열화된다. 이러한 콘크리트 열화는 다공성인 콘크리트 내부에 염분이 침투함으로써 철근부식을 야기하고, 부식된 철근은 보통 $6{\sim}10$배까지 부피가 팽창하면서 콘크리트에 균열을 일으키고 결국 탈락(박리)으로 이어진다. 이와 같은 철근부식과 균열발생의 가속화는 구조물의 심각한 손상과 궁극적으로 붕괴까지 이어질 수 있다. 따라서 이러한 피해를 막기 위해서는 콘크리트 내 철근부식의 정확한 이해가 필요하며, 부식발생의 정량화에 의한 예측은 물론 적절한 방식법을 적용해야한다. 음극방식법은 비교적 최근에 개발된 철근콘크리트 구조물의 방식법 중 하나이며 요즈음도 해외 여러 나라에서 이에 대한 방식시스템 연구가 활발하다. 본 연구에서는 해상교량이나 항만부두 구조물의 상판부에 대한 예비실험 성격으로 슬랩 시험편(40cm ${\ast}$ 30cm ${\ast}$ 18cm)을 채택하였다. 시험환경은 15% 염분과 온도 $40^{\circ}C$의 가속화된 해양환경이었으며, 시험 기간 동안 주기적인 건습 반복을 실시하였다. 방식시험편은 음극방식 기술의 하나인 Zn-mesh에 의한 희생양극식을 채택하였다. 연구내용으로는 음극방식에 의한 방식성능을 관찰하였으며 신설구조물과 보수구조물에 대한 방식 효과를 비교하였다.

• 접착 및 계면
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• 제24권2호
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• pp.69-75
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• 2023

최근 자기복원(self-recovery) 코팅층을 가진 자동차용 도장면 보호필름의 적용이 증대되고 있다. 본 연구에서는 poly(urea-urethane) hybrid 자기복원 코팅층을 가진 poly(vinyl chloride) 기재 보호필름에 대한 기본 물성에 대한 평가 결과를 보고한다. Poly(urea-urethane) 기반 코팅층을 구성하고 있는 주요 화합물의 비율과 코팅층의 두께 변화에 따른 자기복원성능을 확인하였으며, 색차 값 측정을 통해 내오염성능을 정량화 하였다. 또한, 소수성 첨가제로 외부 오염에 대한 표면특성을 향상시키기 위하여, 소량의 실리콘계 반응형 첨가제를 코팅 조성물에 함량에 따른 easy-cleaning 효과와 접촉각을 확인하였다. 마지막으로, poly(urea-urethane) 자기복원 코팅층을 가진 보호필름의 장기간 사용에 따른 변색 및 변형에 대한 가능성을 확인하고자 촉진 내후성 평가를 진행하였다.