• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.134-134
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• 2008

아연도금강판은 유-무기 코팅 처리를 통해 도금층 표면의 방청성 향상과 추가적인 고기능성을 부여한다. 최근 POSCO 에서는 가전, 건재 및 자동차용으로 사용하기 위해 다양한 Cr-free 코팅강판을 개발하였다. 본 발표에서는 기존의 크로메이트 처리 강판을 대체하기 위해 유-무기 복합코팅 강판 개발과 품질특성을 소개하고자 한다.

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.548-551
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• 2014

In order to reduce toxicity on the human body, four new cleaning agents (1-4) containing ester and ether functionalities have been invented. The synthesized cleaning agents's physical properties, biodegradabilities, and $LD_{50}$ values, which were conducted by Korea Testing Certification Institute by using standard method, showed excellent values. A specimen for cleaning ability was prepared by cutting in $60{\times}40mm$ size of stainless steel plate. The surface of the above specimens was treated with four different kinds of contaminants, such as cutting oil, anti-rust oil, drawing oil, and lubricating oil. Contaminated specimens were then immersed in compounds (1-4) for 1 to 5 minutes to dissolve oil in the cleaning agent. The data indicate that all compounds (1-4) exhibit good cleaning ability toward four contaminant oils. It is also confirmed that these compounds can be applicable to various industrial cleaning fields as nontoxic and biodegradable cleaning agents because of their excellent biodegradabilities and $LD_{50}$ values.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.11a
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• pp.87-91
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• 2002

This paper investigates the corrosion inhibition and the reduction of hydration heat properties of Ground Granulated Blast-Furnace Slag (GGBFS) added concrete. Since the massive civil structure is vulnerable to the thermal crack by hydration. adiabatic temperature rising tests were performed for water-binder ratios from 43.2% to 47.3%, while replacing 15% to 50% of cement with GGBFS of equal weight. Then, the corrosion protection performance was evaluated using cylindrical specimens embedded with steel reinforcement according to the combination of 3 W/B ratios and 2 levels of chloride ion quantity. The corrosion area of the embedded steel ban was determined using the high pressure steam curing method specified in KS F 2561. The test results showed that the replacement of GGBFS was effective in reducing the hydration heat. The corrosion area of the embedded steel ban decreased as the replacement of GGBFS increased. However, the corrosion area of the steel bar was proportional to the autoclave cycle and the chloride ion quantity. Among the tested specimens, compressive strength, reduction of hydration heat, and corrosion inhibition performance were excellent when 50% of cement was replaced with GGBFS of equal weight.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1358-1364
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• 2019

The mechanical properties of Heavy duty resin of synthetic polyurethane-epoxy resin for stainless steel were measured by SEM, FT-IR, tensile properties, and specific mass loss by EIS analysis, etc. As interest in eco-friendly medium coatings increased, the Heavy duty coatings were synthesized for various metals such as stainless steel composed of Polyol, MDI, water bored Epoxy resin, filling agent, silicon surfactant, catalyst etc. The coatings of synthetic Heavy duty resin were increased tensile strength due to various temperature change, and the low-Specific Mass Loss was measured in a highly electrolytic solution. In conclusion, the Heavy Duty coatings composed of polyurethane and waterbored Epoxy resin were synthetic microstructure with cross linkage can be good material for coating of anticorrosion of metal substrates such as stainless steel.

• Journal of Ocean Engineering and Technology
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• v.23 no.4
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• pp.64-68
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• 2009

It has been observed that coated steel structures deteriorate more rapidly than the designed lifetime due to acid rain caused by air pollution, etc. Therefore, improving the corrosion resistance of anti-corrosive paint is very important in terms of safety and the economic point of view. In this study, the corrosion resistance of five kinds of anti-corrosive paints, including the Acryl, Fluorine, and Epoxy resin series, were investigated with electrochemical methods, such as corrosion potential measurements, polarization curves, diffusion limiting current density, etc. As a result, the corrosion resistance of the F101 specimen with the fluorine resin series was found to be superior to the other specimens, while E100 with the epoxy resin series also showed a somewhat good corrosion resistance. Furthermore, it was observed that the amount of water and oxygen entering the inner side of a painted film increased with an increase in immersion time, irrespective of the kind of resin series. However, the oxygen diffusion limiting current density of a specimen with good corrosion resistance was relatively decreased compared to other specimens, because of the difficulty of oxygen diffusion penetrating to the inner side of the film. Consequently it is suggested that we can qualitatively evaluate the corrosion resistance of an anti-corrosive paint by measuring the diffusion limiting current density as an electrochemical method.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.212-216
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• 2005

Benzotriazole which is used as a corrosion inhibitor for the zinc coated steel was intercalated into Na-MMT. X-ray diffraction experiments on intercalant/silicate composite samples demonstrated that the intercalation of intercalant leads to an increase in the spacing between silicate layers. Water soluble poly(ethylene-co-acrylic acid) (PEA) nanocomposites, to use as a coating agent, were prepared with these modified MMT. We found that mono-layered silicates were dispersed in PEA matrix and those resultants were exfoliated nanocomposites. From the result of salt spray test, we found that this coating agent prepared with water soluble poly(ethylene-co-acrylic acid) (PEA) nanocomposite provided good corrosion protection. These results were caused by decreasing the rate of oxygen permeation from silicate layers dispersed homogeneously in PEA matrix and the effect of corrosion inhibitor from benzotriazole.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.1
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• pp.239-247
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• 2004

When the concrete is subjected to chloride attack or carbonation, the passive steel normally initiate corrosion. By product of corrosion make volume of concrete expand 3 to 8 times and induce the stress which lead cracking and spalling of concrete. It result in the loss of the integrity of the concrete structures. Several corrosion inhibitors imported from America, Japan and Europe are currently being used to repair the concrete structures in Korea. However, questions has been raised for protective effect of the corrosion inhibitors which applied in steel reinforced concrete structures. Therefore, we investigated the influence of type and amount of corrosion inhibitors through the tests immersing in salty water. In addition, we developed the corrosion inhibitive agent treating to surface of concrete structures for improving resistance to penetration and corrosion of the steel reinforcement.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.409-414
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• 2002

This study is intended to develop the self water proof admixture for durability concrete by anti-corrosion inhibitor. Chloride induced corrosion of reinforcement is one of the main factor which cause the deterioration of concrete structure. When the substitute anti-corrosion agents for a part of self waterproofing agent, the corrosion-proof increases for the increased water proofing capacity. And proper self waterproofing agent by cement weight in concrete was generally positive effect to concrete compressive strength, slump, freezing and thawing resistance. Also, permeability and absorption show a straight decrease when self waterproofing agent is added.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.641-646
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• 1998

The structures exposed to marine environment do not show long-term durability due to corrosion of steel and deterioration of concrete by the attack of various salts dissolved in sea water. In this study, Partial substitution of cement with fly ash(20%) or blast furnace slag(40%) was made together with the addition of 4 different corrosion-inhibitors, as a protective measure of concrete structures against chemical attack of salts. Combined effects of mineral and corrosion-inhibiting admixtures were tested by measuring the resistance and compressive strength of concretes under the simulated tidal condition, which consists of alternating 12 hour periods of immersion in artificial sea water and drying in air. Both the strength and concrete resistance were found to decrease in following order, regardless of the corrosion inhibitors the concretes with blast furnace slag, those with fly ash and those without any mineral admixtures. The interrelation between compressive strength of concrete and resistance was investigated.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.142-147
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• 1994

Lately, among concrete component used in construction works, the aggregate is the most important material because it hold about 70~80 Vo1% of most structural materials. Considering that the demand of aggregate is on the continuous increase in the construction works year after year, it is a very urgent thing to develop a substitute aggregate for river aggregate. This paper, an experimental study on the effect of corrosion protection by tighting concrete used fly-ash and silica fume, is to investigate workability and engineering properties of concrete used fly-ash and silica fume. As a test results, contrary to SF, workability of concrete used FA is inclined to be improved. And in the case of containing SF, the compressive strength containing admixtures is higher than plain concrete with increasing curing age.