• Title/Summary/Keyword: 방청

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Preparation and Performance Evaluation of Zinc Phosphate-Coated Mica Anticorrrosive Pigment (운모상에 인산아연이 도포된 방청안료의 제조 및 성능평가)

  • Lee, Yu Jin;Park, Seong Soo;Hong, Seong Soo;Lee, Seung Ho;Kim, Dae Sung;Lee, Gun Dae
    • Clean Technology
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    • v.19 no.3
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    • pp.257-263
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    • 2013
  • The zinc phosphate-coated mica (ZP/mica) pigments were prepared using phosphoric acid, zinc nitrate and mica as starting materials, and used as anticorrosive pigments. The scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were used to observe the morphology and crystal structure of prepared pigments. The prepared pigments were incorporated into an epoxy binder to prepare coating and the corrosion inhibition performance of the pigments was evaluated using electrochemical impedance spectroscopy (EIS). It was found that the anticorrosive performance of the ZP/mica pigment prepared at $70^{\circ}C$ was the better than that prepared at $20^{\circ}C$. The formation of ZnO, in addition to $Zn_3(PO_4)_2{\cdot}2H_2O$, was observed on ZP/mica pigment prepared at $70^{\circ}C$. The excellent anticorrosive performance of ZP/mica pigment could be ascribed to the synergistic effect with electrochemical anticorrosive mechanism from zinc compounds on mica and barrier anticorrosive mechanism from lamellar mica.

Corrosion-Inhibition and Durability of Polymer-Modified Mortars Using Redispersible Polymer Powder with Nitrite-Type Hydrocalumite (재유화형 분말수지와 아질산형 하이드로칼루마이트를 병용한 폴리머 시멘트 모르타르의 방청성 및 내구성)

  • Kim, Wan-Ki;Hong, Sun-Hee
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.3
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    • pp.275-283
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    • 2012
  • Nitrite-type hydrocalumite (calumite) is a material that can adsorb the chloride ions ($Cl^-$)that cause the corrosion of reinforcing bars and liberate the nitrite ions ($NO_2{^-}$) that inhibit corrosion in reinforced concrete, and can provide a self-corrosion inhibition function to the reinforced concrete. In this study, VA/E/MMA-modified mortars with calumite were prepared with various calumite contents and polymer binder-ratios, and tested for corrosion inhibition, chloride ion penetration, carbonation and drying shrinkage. As a result, regardless of polymer-binder ratio, the replacement of ordinary Portland cement with hydrocalumite has a marked effect on the corrosion inhibiting property of the polymer-modified mortars. However, chloride ion penetration and carbonation depths are somewhat increased with higher calumite content, but can be remarkably decreased depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to increase with the polymer-binder ratio and calumite content. VA/E/MMA-Modified mortars with 10 % calumite did not satisfy KS requirements. Accordingly, a calumite content of 5 % is recommended for the VA/E/MMA-modified mortars with calumite.

A Study on the Characteristic of Anti-corrosive Performance for the Cable Members (케이블 부재의 방청성능 특성에 관한 연구)

  • Ahn, Seung-Whan;Han, Sang-Eul;Lee, Sang-Ju
    • Proceeding of KASS Symposium
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    • 2006.05a
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    • pp.66-72
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    • 2006
  • Recently nonlinear materials are used in construction of building and bridge then various structure formats are achieved positively. one of them, cable members, are the interesting study object which increase rigidity of a total structure by inducing tension. The way of construction using cable members is increasing, so the technology of design and construction are developing. Protection Fretting Fatigue is very important to maintain efficiency of cable member permanently. However, recognition of this is somewhat humble and this paper considers anti-corrosive performance of cable.

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An Experimental Study on Corrosion Resistance of Epoxy Coated Reinforcements (에폭시 도포철근의 내 부식성능에 관한 실험적 연구)

  • 오병환;엄주용;권지훈
    • Magazine of the Korea Concrete Institute
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    • v.4 no.4
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    • pp.161-170
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    • 1992
  • 근래 들어 철근 콘크리트에 있어서의 철근부식이 관심의 대상이 되고 있는데 그이유는 이 현상이 실제 구조물에서 광범위하게 발생함이 확인되었고 이로 인한 보수비용이 급증하였기 때문이다. 철근의 부식이 처음 거론된 것은 해양구조물과 내화학성 구조물에서였고 최근 들어서는 교량상판, 주차공간등 염기에 노출되어 철근 부식이 우려되는 각 종의 구조물에 광범위하게 그 대책이 연구되기에 이르렀다. 이와같은 철근부식이 제어방법으로는 첫째로 콘크리트의 수밀화를 들 수 있고 다음으로 콘크리트의 표면을 처리하거나 피복두께를 늘이는 방법이 있다. 마지막으로 철근자체에 방청성능을 직접 부여하여 방법에 속하는 에폭시 도포 철근의 기본적인 방청성능을 고찰하기 위해 수행되었다. 연구결과 에폭시 도포철근의 방청성능은 매우 우수함을 발견하였고 앞으로 활용이 기대되고 있다.

An Experimental Study on the Resistance to Penetration of Harmful Ions in Surface Coatings Material Containing Organic Corrosion inhibitor (유기계 방청제를 혼입한 표면피복재의 유해이온 침투저항에 관한 실험적 연구)

  • Ryu, Hwa-Sung;Shin, Sang-Heon;Lee, Han-Seung
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.2
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    • pp.157-166
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    • 2017
  • In general, carbonation and chlorine ions are the most harmful causes of deterioration of concrete structures. Recently, a method has been developed to control the corrosion of rebar in concrete containing chloride by impregnating a Surface coating material with a inhibitor. In this study, accelerated carbonation and differential thermogravimetric analysis (TG-DTA) and CASS tests were carried out to evaluate the characteristics of Surface coatings containing Organic Corrosion inhibitors which are excellent in corrosion inhibition and fix degradation causes $CO_2$ and $Cl^-$. As a result of the experiment, TG-DTA analysis and accelerated carbonation showed that $CO_2$ was directly reacted with amine derivative in concrete by the incorporation of Organic Corrosion inhibitor. In other words, $CO_2$ was immobilized and carbonation inhibition effect was confirmed. In addition, in the CASS test, the specimen coated with the Surface coating material containing the Organic Corrosion inhibitor with $Cl^-$ fixing property showed no corrosion until the 28th day and had excellent performance in preventing corrosion of a rebar by the chloride ion.

A Study on Chloride Threshold Level of Polymer Inhibitive Coating Containing Calcium Hydroxide (수산화칼슘을 혼입한 폴리머 방청 코팅의 부식 임계치 향상에 대한 연구)

  • Song, Ha-Won;Lee, Chang-Hong;Lee, Kewn-Chu;Ann, Ki-Yong
    • Journal of the Korea Concrete Institute
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    • v.20 no.6
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    • pp.713-719
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    • 2008
  • Various types of coatings have been developed for use as reinforcement in concrete and to resist chloride environment. The most commonly used coatings are inhibited and sealed cement slurry coating, cement polymer compositing coating and epoxy coating. Cement slurry offers passive protection, epoxy coating offers barrier protection whereas polymer coating offers both passive protection and barrier protection. Moreover, damage during handling of the steel may result in disbondment of the epoxy coating, which would increase the risk of localized corrosion. In the present study, inhibiting technique was used to increase the calcium hydroxide content at the interface up to 20%. Calcium hydroxide provides a high buffering capacity that resists a local fall in pH and thus maintains the alkaline environment necessary to prevent chloride corrosion. This study examines the use of a calcium hydroxide coating on the steel surface to enhance the pH buffering capacity of steel-concrete interface. Finally, the chloride threshold level (CTL) of polymer inhibitive coating calcium hydroxide is evaluated.