• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.104-104
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• 2009

금값 폭등과 에너지자원 고갈에 따라 폐 인쇄회로기판의 유가금속 및 에너지자원을 효과적으로 회수하고자, 최근 국내외 금 회수 및 폐백보드 활용방안을 제시하였다. 금을 회수하는 방법으로는 침적박리, 농축처리, 중화처리, 수용액환원처리, 이온교환수지, 전해채취 등의 방법이 있다. 금은 상온침적박리 회수하며 폐백보드는 이동식 건축내장재로 활용하고자 한다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.34-35
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• 2015

Recently, introduction of Advanced water treatment facilities has been increasing due to serious domestic water pollution. Ozone is a strong oxidizing materials in the advanced water treatment facilities. However, due to such a strong oxidation, Ozone eroded waterproofing/corrosion on the concrete surface and caused performance degradation. Therefore, in this study, permeability experiment of metal spraying system by concrete surface treatment was conducted.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.485-488
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• 2002

최근 산업용 유리섬유는 고부가가치 응용분야로 대형 막구조(membrane structure)와 의공학 부품, 인쇄회로기판 등에 응용되고 있으며, 광통신의 주체인 광섬유로 활용되며 점차 그 용도를 넓혀가고 있다. 특히, 근래에 관심을 모으는 유리섬유 복합재료를 이용한 대형 막구조물은 경제성과 건축의 용이성 및 신속성 면에서 기존 건축구조보다 유리하고, 내구성도 우수하기 때문에 그 활용이 증가하고 있다. (중략)

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.13-14
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• 2012

This study investigates the effect of adhesive type applying to surface-strengthening Ondol floor on level of attachment. Adhesive materials of four types produced in different companies were prepared and their attaching performance was examined. Test results showed that the water-based epoxy type produced in S company was the most effective on attaching the pieces of the surface-strengthening Ondol floor product.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.50-51
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• 2016

Ozone is a strong oxidizing materials in the advanced water treatment facilities. However, due to such a strong oxidation, Ozone eroded waterproofing/corrosion on the concrete surface and caused performance degradation. Therefore, in this study, permeability experiment of metal spraying system by concrete surface treatment was conducted.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.161-162
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• 2020

In this study, as part of securing related data, water droplets were dropped on the upper part of the wooden board for flooring in an environment such as floor heating, and the degree of absorption according to the surface temperature change was tested. The test results showed that the contact angle of the surface was low (25℃→40℃) or the droplet was absorbed into the small plate and disappeared. The contact angle of the OSB and MDF was decreased within 30 minutes, but the surface water droplet was maintained longer than the plywood. This is because the surface is coated with hydrophobicity unlike the plywood, but moisture absorption in the cross section after the second processing will not be prevented and it will lead to defect occurrence problem.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.42-49
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• 2020

This paper is a basic study to improve durability by imparting hydrophobicity to the surface and sphere of cement-based materials. A cement mortar to which a silane/siloxane-based mixed water repellent was added was prepared, and its initial hydration performance, flow performance, and compressive strength were measured. In addition, after the surface was abraded, the water contact angle and water absorption were measured. The flow of cement mortar to which the water repellent was added was found to decrease up to 1.5% in the addition amount of the water repellent agent, and increased at 3.0% in the addition amount. It was found that the setting time of the cement paste was delayed in both the initial setting and the termination when the water repellent was added. It was found that the compressive strength decreased from 3.0% of the maximum added amount of the water repellent to a maximum of 30%. The contact angle was found to increase when the water repellent was added to the cement mortar, and the contact angle after surface polishing was found to be larger than before surface polishing. The addition of the water repellent showed hydrophobicity not only on the surface but also on the surface and cross section damaged by polishing. The water absorption rate was found to decrease when the water repellent was added to the cement mortar, and the water absorption rate after surface polishing was found to be greater than before surface polishing.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.24-31
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• 2024

Mortar has been applied in most previous studies on 3D concrete printing. In such cases, however, the economic efficient cannot help decreasing due to higher binder contents and larger amount of fine aggregates. In order to enhance the applicability of 3D printing technology to construction industry, therefore, 3D concrete printing technology utilizing coarse aggregates needs to be developed further. This study aims at proposing the mix design process of concrete containing coarse aggregates for 3D printing. Based on extensive literature review and experimental studies, the mix proportion suitable for 3D printing has been derived, and the extrudability of concrete with coarse aggregates has been verified through 3D printing tests. The primary variable of the extrudability tests was the contents of viscosity modifying agent (VMA), and the extrudability was quantitatively evaluated by measuring dimensions, distribution of aggregates, and surface quality of 3D-printed filaments. The test results showed that the dimensional suitability and surface quality were improved as the VMA contents were larger, and the coarse aggregates were evenly distributed in the section of filament regardless of the VMA contents. Based on the test results, the mix design process for concrete containing coarse aggregates for 3D printing has been proposed.

• Journal of the Korea Institute of Building Construction
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• v.15 no.6
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• pp.579-587
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• 2015

In this paper, microencapsulated healing agent was embedded in the polymer matrix to obtain self healing properties. Microencapsulation of methacrylate using polyurea-formaldehyde as a shell material and studied the effect of agitation rate on capsule characteristics such as size, shell thickness, and surface morphology. The formation of microcapsules was confirmed by FTIR and TGA, and capsule characteristics were studied by optical microscopy and SEM. The self-healing effect was evaluated using permeability measurements and further confirmed by surface analytical tools including optical microscope. According to the experimental results, the microencapsulated healing system has the self-heaing ability for artificial cracks.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.251-257
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• 2018

There are various quality deteriorations of concrete such as plastic, drying shrinkage due to abrupt moisture evaporation, slump loss and cold joint under hot weather condition. To protect from above deteriorations, several kinds of modified bubble sheets have been applied to secure heat insulation performance. But, there is not enough application cases of bubble sheets at job site under hot weather condition. The objective of the paper is to investigate the temperature profile and crack occurrence of the concrete covered with five different kinds of surface curing sheets, which is placed under hot weather condition. Single layer transparent bubble sheet, white colored bubble sheet, aluminum metalizing bubble sheet and PE film are adopted for surface curing sheets. Test results indicated that application of aluminum metalizing bubble sheet had most favorable effect on the reduction of on temperature rise and on the crack reduction of concrete. But due to larger reflection of light by aluminum, it brings about visual pollution to the workers. Hence, the application of white colored bubble sheet can be the most desirable alternative to protect the concrete from hot weather in the field.