• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.63-67
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• 2003

There are many factors that generate the early deterioration of the concrete structure. As the one of the representative factors, we can think an invasion of the water, air and so on. The water and air invade in inside void along the capillarity and they become the cause that the durability like corrosion of layer department due to freezing and thawing, inside steel frame corrosion, and so on blacks. Therefore with covering permeability covering waterproofing material of fluid condition in outer wall, intercepting the deterioration factor due to the infiltration of water from outside and for salt damage of concrete layer department, freezing damage and neutralization, it needs to improve durability of structure. This study separately examined physical and chemical specific of quality liquid siliceous of waterproofing material. Therefore as this applys the construction site, it improves the durability of concrete structure. Further this presents the application plan from the construction market against the new material.

• 보존과학회지
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• 제6권1호
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• pp.79-88
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• 1997

책과 문서의 보존은 매우 중요하고 시급한 문제이다. 여기에서는 책과 문서를 만드는 종이의 열화 원인, 열화를 억제하거나 방지하는 화학적 방법, 그리고 고분자를 이용한 물리적 보강 방법, 열화가 산성 종이에 비해 매우 느린 알카리성 종이 제법, 그리고 최근 책과 문서에 사용되는 종이에 대한 규정 등에 관해서 개관하고 토의하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.31-32
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• 2020

Concrete changes its internal moisture distribution depending on the external environment, and changes in the condition of the material's interior over time affect the performance of the concrete. These effects are closely related to the long-term behavior and durability of concrete, and the degree of deterioration varies from climate to climate in each region. In this study, we use actual climate data from each region with distinct climates. A multi-physical analysis based on the method was conducted to predict the difference and degree of deterioration rate by climate.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.140-141
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• 2020

Concrete has a lower thermal conductivity or thermal diffusion coefficient compared to other building materials, so it is widely used as fireproof compartment material or refractory material for structures. However, in the event of thermal damage such as fire, cement curing agents and aggregates act differently, resulting in heat generation or deterioration of tissue due to dehydration, resulting in deterioration of physical properties and fire resistance. Therefore, in this study, the processing structure of cement paste is measured through nitrogen absorption method. The test specimen is a cement paste of 40% W/C and is set at 1000 ℃ under heating temperature conditions. As the temperature rose, the micro-pore mass below was reduced based on about 0.01 감소m, but the air gap above that was increased.Thus, in the range of pores measured in nitrogen adsorption, the air mass tended to decrease under high temperature conditions.

• 보존과학회지
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• 제35권4호
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• pp.279-293
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• 2019

The stone lantern of the Damyang Gaeseonsaji temple site is a cultural heritage built during the Unified Silla period (AD 868). The reason for its value as a cultural property is due to wittern the background and the period created on inscription of the lamp stone engraved by letters. The stone lantern consists of two types of lithic tuffs for the 23 original properties, the replaced stones in 1991, and the biotite granite for its ground stones replaced in 2005. The lithic tuffs selected as the replacement parts in 1991 and 2017 have been examined and got to properties of hardly exposure moisture as well as very similar geochemical characteristics. There were various types of physical deterioration of the stone properties and structural cracks; in particular, on the northern side of the stylobates. Chemical and biological deterioration can be identified as black, white, and brown discolorations as well as by the presence of lichens, bryophytes, and herbaceous plants. In the evaluation of the physical properties of the stone lantern, the mean and maximum ultrasonic velocities were found to be similar in each direction. However, the lowest velocity on the east and south sides were found to be lower than those of other stone properties. It was found that physical damage to the stylobates resulted from water expansion in a freeze-to-thaw phenomena related to water content. Therefore, dismantling repair was carried out in the protection facility to restrict further water supply to the stone as much as possible.

• 열처리공학회지
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• 제37권3호
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• pp.114-120
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• 2024

AA 2026, which is used as an aviation material, is an improved version of 2024 and has higher physical properties, and is a material that has the potential to be applied to supersonic aircraft to be developed in the future. However, when an aircraft exceeds supersonic speeds, the surface heats up and the material must be resistant to this. Therefore, this study confirmed the high-temperature properties of AA 2026, an aviation structural material. AA 2026, solution treated at 500℃ for 4hr, was naturally aged at room temperature for more than 168 hr. Changes in microstructure and physical properties were confirmed over several hours of exposure to 100℃, 200℃, and 300℃, respectively. As a result of microstructure analysis, there was no significant change at 100℃, and from 200℃, GPB, a strengthening mechanism, grew and formed an S Phase. It was confirmed that the S Phase grew as the exposure time increased. Through a tensile test, it was confirmed that physical properties deteriorated as the precipitates grew. However, it was confirmed that the properties were stably maintained at 100℃, which is the temperature when the speed of a supersonic aircraft is less than Mach 2.

• 지질공학
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• 제23권4호
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• pp.341-352
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• 2013

본 연구에서는 생성 당시의 퇴적환경이 상이한 것으로 알려진 대구지역의 적색 셰일과 흑색 셰일의 물리적 및 역학적 특성을 확인하기 위하여 단위중량, 흡수율, 공극률, 초음파속도, 일축압축강도, 점하중강도, 슬레이크 내구성 및 열화특성 시험 등을 실시하였고, XRD 및 XRF 분석과 SEM 영상 분석을 수행하였다. 시험결과 두 셰일의 단위중량은 유사하였으나 흡수율과 공극률은 적색 셰일이 흑색 셰일보다 더 높았다. 특이하게도 공극률이 높은 적색 셰일의 초음파속도, 일축압축강도, 점하중강도지수 가 흑색보다 더 높은 값을 보였는데 이는 흑색 셰일 내에 발달된 엽층리의 영향인 것으로 판단된다. 열화시험에서는 용액의 산성도가 증가할수록 또 수침시간이 길어질수록 시료의 점하중강도지수와 슬레이크 내구성지수의 저감정도가 심하였으며, 흑색 셰일보다는 공극률이 큰 적색 셰일에서 더 크게 영향을 받는 것으로 나타났다.

• 보존과학회지
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• 제29권2호
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• pp.93-102
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• 2013

속초 신흥사 목조지장보살삼존상(보물 제1749호)은 신흥사 명부전에 안치되어 있다. 이 삼존상에는 부분적으로 균열, 박락 등의 물리적 손상과 안료 변색, 균류 서식 등의 화학적 및 생물학적 손상이 발생하였다. 이 연구에서는 삼존상의 손상도 평가 및 보존계획을 수립하기 위해 손상지도 작성, 초음파 측정, X-선 및 내시경 촬영 등의 비파괴 정밀진단을 수행하였다. 이 결과, 지장보살에서는 개금층 박락이 관찰되며 각종 오염물이 불상표면에 고착되어 있다. 무독귀왕은 누수에 의한 안료변색이 심하다. 도명존자는 노출된 목부재에서 곤충의 서식흔적이 확인되었으며, 내부에서는 벌집이 관찰되었다. 따라서 이 손상도 진단 결과를 바탕으로 삼존상의 원형을 보존하기 위한 보수가 필요한 것으로 판단된다.

• 환경영향평가
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• 제22권4호
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• pp.303-317
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• 2013

The purpose of this study is to offer the raw data for restoration and management of trails by assessing the physical environments, the types of deterioration and the naturalness on trails located in the Sogeumgang, Hwarang and Seoak districts of Gyeongju National Park, Korea. The Sogeumgang was 5.9m, 1.1m of the Hwarang and 1.8m of the Seoak district in trail width. In the bared width of trail, the Sogeumgang was 3.9m, 0.9m of the Hwarang and 1.7m of the Seoak district. In the depth of erosion, the Sogeumgang was 37.1cm, 14.2cm of the Hwarang and Seoak district. The Sogeumgang was $16.8^{\circ}$, $13.1^{\circ}$ of the Hwarang and $12.2^{\circ}$ of the Seoak district in longitudinal slope. In the left and right of transect slope, the Sogeumgang was $18.3^{\circ}$ and $12.6^{\circ}$, $18.0^{\circ}$ and $21.3^{\circ}$ of the Hwarang and $15.3^{\circ}$ and $22.7^{\circ}$ of the Seoak district. In the left, middle and right of soil hardness, the Sogeumgang was 29.9mm, 34.7mm and 31.1mm, 27.6mm, 35.0mm and 27.2mm of the Hwarang and 27.1mm, 30.8mm and 28.0mm of the Seoak district. The types of deterioration in trails were 10 types of the Sogeumgang, 11 types of the Hwarang and 9 types of the Seoak district. The trail erosion, rock exposure and root exposure were substantially observed in the types of deterioration. In the results of the naturalness assessment, the Hwarang district was a good condition, but the Sogeumgang district was bad. The indicators of the Sogeumgang district were mostly poor.

• 한국지반공학회논문집
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• 제23권6호
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• pp.77-84
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• 2007

유입량과 라이닝에 작용하는 간극수압은 터널 설계시 고려해야 할 중요한 요소 중 하나이다. 간극수압의 발생은 누수를 가속화시키며 라이닝 열화를 초래한다. 본 논문에서는 모형실험을 통하여 배수시스템 기능저하로 인한 간극수압의 발생과 그 영향을 조사하였다. 배수시스템 기능저하거동은 배수재의 투수계수제어법과 유량 조절법으로 모사화 하여 터널 라이닝의 잔류수압발생 메카니즘을 확인하였다. 또한, 유량제어법이 배수시스템 기능저하현상을 모사하기에 보다 더 효과적인 방법임을 알 수 있었다. 모형실험을 수치해석으로 재현한 결과, 배수시스템 기능저하로 인한 영향을 Coupled 수치 모델링을 통해 이론적으로 예측 가능함을 확인할 수 있었다.