• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.177-186
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• 2005

The latest concrete structure has showed that the deterioration of durability has been increased by the damage from salt, carbonization, freezing & thawing and the others. Therefore, the measures for the concrete which has deteriorated durability have been taken. Among them, it has been often used that surface treatment which cuts off the deterioration factors of durability by protecting the surface of concrete. However, troubles such as fracture and rupture in the repair layer have been reported as time goes by due to the difference between the organic repair material like epoxy and concrete properties. Researchers have been developing the repair material which can cut off the deterioration factors of durability such as $CO_2$ gas, chloride ion and water by making the formation of concrete elaborate through the reaction with calcium ion when the surface improving agent is coated on the concrete. The main ingredient of that is inorganic substance which is the same as the concrete property. This study was evaluated the surface improving agent for permeability, watertightness, air-permeability, chemical resistance and elution resistance. As a result, it has been reported that the surface improving agent improves watertightness and air-permeability by penetration more than 10mm within concrete. Therefore, it is concluded that the surface improving agent developed in this research prevents deterioration of concrete durability when it is coated on the concrete structure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.6
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• pp.77-86
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• 2007

The repair technique utilizing surface impregnant is widely used due to its simple construction procedures and economical benefit. Surface protection through this reparing technique cannot increase the bearing capacity of concrete members much but increase the durability performance and service life efficiently. In this study, fundamental tests such as water suction and permeation are performed for concrete specimens with several organic/inorgarnic impregnant and suitable impregnant is selected on the basis of the results. Finally, durability tests such as carbonation, freezing and thawing, and chloride attack are carried out for the concrete specimens with selected impregnant and it is experimentally verified that they have good resistance to deteriorations.

• Journal of the Korea Concrete Institute
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• v.19 no.4
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• pp.475-482
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• 2007

The property and applicability of the organic-inorganic synthesized penetrating and reinforcing agent, which is developed in order to improve durability of concrete structures and prevent deterioration that may occur as service years increased, are researched with experimental works. TEOS (tetra-ethoxyorthosilicate) and acrylate monomer are synthesized by the solution polycondensation method in order to formulate silicate with sol-gel process and improve durability of concrete. Additional substances such as isobutyl-orthosilicate is supplemented in order to improve the performance of the agent. After the developed organic-inorganic penetrating reinforcing agent penetrates, a flexible impact alleviating layer is formed with organic monomers as well as the agent strengthens concrete by filling up the internal pore of concrete with stable compounds after penetration. Penetrating and reinforcing agent can be applied as an effective life management method because it makes concrete more durable against the aging factors, such as chloride ion, carbonation, freezing-thawing, and compound aging.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.433-436
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• 2008

Deterioration in the concrete structure are due to carbonation, chloride ion attack and frost attack. Therefore, concrete structure is needed to surface protection for increase durability using silicate impregnants. Thus, this study is concerned with self-cleaning and durability of silicate hydrophilic impregnants of concrete structure using lithium and potassium silicates. From the experimental test results, lithium and potassium silicates have a good properties as a carbonation resistance. Lithium and potassium silicates make good use of hydrophilic impregnants of concrete structures.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.489-498
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• 2005

Recently, the deterioration of concrete structures have been increased by the damage from salt, carbonization, freezing & thawing and the others. Therefore, the measures for the deterioration of concretes have been taken. Among them, it has been often used that surface treatment which cut off the deterioration factors of durability by protecting the surface of concrete. The water proof and repair materials for concrete mainly use organic materials such as epoxy, these materials excel in intial bonding force and resistance to chemical agents. But they cause difference in the modulus of elasticity and the rate of shrinkage and expansion of concrete, and thus result in such problems as scaling and spatting in the progress of time. Therefore in this study it develop the performance Improving agent of concrete surface that can block a deterioration cause such as $CO_2$ gas, chloride ion and water from the outside and enhance waterproofing ability by reinforcing the concrete surface when applying it to concrete structures.

• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.28-35
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• 2000

This paper deals with a coating technique for hardening surface layer of softwood(Larix leptolepis) flooring board to improve its surface properties such as hardness and abrasion resistance, Two coating methods were applied for surface hardening of the wood in this study. First, several functional monomers were added in UV-curing epoxy acrylate varnish. Secondly, unsaturated polyester varnish was used as under coat and acryl varnish including anti-abrasive agent was used as top coat. The hardness of the treated wood was similar to that of high density hardwood such as keruing by the first coating method. The abrasion resistance of the coated wood was greatly improved by the second method. Adhesion properties and impact resistance of the coated wood surface were also good. It was suggested that the well-coated softwood could be used as interior flooring board for heavy walking as substitute for hardwood.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.300-302
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• 2001

폴리카본산계 기능성 고분자를 합성해서 고성능 감수제 원료로 활용하여 고유동화 혼화제를 개발하고자 한다. 폴리카본산계 기능성 고분자를 합성한 후, 이를 고유동, 고강도 혼화제 원료로의 제반 물성을 확인하고, 이를 현장에 적용하여 현재의 제품을 획기적으로 개선하고, 혼화제 품질의 우위성을 확보하기 위해 1) 시멘트 및 골재 표면에서의 적절한 계면활성을 갖는 분자설계를 하였으며, 2)분자량의 조절 기술의 개발을 개발하였다. 합성에 있어서 첫째, 시멘트 및 골재 표면에서의 적절한 계면활성을 갖는 분자설계와 둘째, Mw 5,000정도의 분자량을 갖는 감수제의 합성기술을 개발하였다. 이렇게 제조된 고성능 유동화제의 화학구조 해석을 해석하고 분자량 및 분자량 분포를 측정한 다음, 시멘트 페이스트의 유동성, 점도, 슬럼프로스 등을 측정하여 고성능 유동화제의 성능인 시멘트 페이스트의 유동성을 시험하였다. 그 결과 고유동성을 갖는 것과 장시간 안정한 유동성을 나타내었으며, 경과 시간에 따른 겉보기 점도변화를 측정한 결과 점도의 상승이 초기에 일어나다가 시간의 경과에 따라 점도가 감소하는 경향을 나타내었다. 따라서 경과시간에 따른 유동성 손실을 억제할 것으로 기대한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.695-704
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• 2016

Rubber deposited during aircraft landing is known as the main cause of reducing surface friction force on wet surfaces. Thus, rubber deposits are removed at regular intervals for sae airplane landing. The high-pressure waterblast method, widely used for the removal of rubber deposits, is regarded as the main cause for the loss of surface material because in this method, water hits the surface directly at a high pressure. In this study, a rubber removal primer is developed to reduce surface damage by lowering the pressure of waterblast relatively during the removal of rubber deposits such that the deposits are removed efficiently even with a lower water pressure. To achieve this, basic materials appropriate for the primer were selected and their performance, penetration rate, and site applicability were evaluated. Based on the evaluations, the proportion of additive required for improving the performance of the basic materials was first determined. Then, the optimum mix ratio was derived through the evaluation of the effect on pavements, and the development of the rubber removal primer was completed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.47-54
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• 2018

Concrete undergoes various deterioration on surface. Impregnant with silicate is usually applied to concrete surface and forms insoluble hydrates, which can provide many engineering advantages. In the work, concrete impregnated with colloidal silicate is used for durability enhancement in surface and self-clearing performance is evaluated with photocatalyst-$TiO_2$ spraying. For the work, various tests are performed both for strength evaluation and durability evaluation such as absorption ratio, drying shrinkage, chloride penetration, sulfate resistance, and freezing/ thawing action. Furthermore, removal and self-clearing performance are evaluated with Acetaldehyde decomposition and Methylene blue decolorization. Through silicate impregnation and photocatalyst spraying, the impregnated concrete can have not only durability enhance but also self-clearing performance.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1777_1778
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• 2009

한국수자원공사에서는 1998년부터 단계적으로 12~14 GHz의 Ku-band 대역을 사용하고 있는 무궁화위성을 이용하여 우량 및 수위, 경보 등의 데이터를 송수신하고 있으며, 특히 강우가 집중되는 기간 동안에는 그 데이터의 필요성이 더욱 큰 실정이다. 사용하고 있는 위성통신망 주파수의 파장은 2~2.5 cm 이므로 물방울 입자에 의해 산란되는 특징을 가지고 있으며, 이로 인해 안테나 및 휘드혼의 표면에 물방울이 묻어 있으면 전파가 산란되어 신호가 감쇠되는 특성을 가지고 있다. 따라서 본 연구에서는 강우시 안테나 및 휘드혼 표면에 발생하는 물방울 맺힘 현상에 대해 물방울과 전파신호간의 상관관계를 분석하고, 위성안테나 성능을 개선방안을 시험하여, 강우로 인한 위성신호의 감쇠를 최소화하여, 최적화된 안테나 성능 구현으로 강우 영향을 최소화하여 안정적인 위성단말국을 운영하고자 한다.