• Proceedings of the Korean Reliability Society Conference
• /
• 2002.06a
• /
• pp.147-155
• /
• 2002

본 연구에서는 옥외에서 사용하는 소재의 신뢰성 평가(내후성)에 관한 연구를 수행하였는데 국내와 일본의 옥외환경시험장에 시험편을 동시에 폭로하여 기상인자 및 주변환경에 따른 시험편의 특성 변화를 상호 비교ㆍ평가하였고 인공 촉진내후성 시험을 실시하여 옥외내후성과의 상관관계를 관찰하였으며 그 결과는 다음과 같다. 국내 지역의 옥외환경시험장 중에서는 인천 옥외환경시험장에 폭로한 시험편에서 가장 많은 변화를 나타내고 있으며, 일본 지역은 가혹한 기상환경을 나타내는 미야고지마 옥외환경시험장에 폭로한 시험편에서 많은 변화가 나타남을 관찰할 수 있었는데 국내 지역보다는 온도와 습도 등 기상제조건이 더 가혹한 일본 지역의 옥외환경시험장에 폭로한 시험편의 노화가 더 빠르게 진행됨을 관찰하였다.

• Journal of Conservation Science
• /
• v.36 no.6
• /
• pp.549-561
• /
• 2020

This study aimed to assess the performance and life of nine natural mineral dancheong pigments: Seokganju, Jinsa, Hwangto, Jahwang, Wunghwang, Seokrok, Noerok, Seokcheong, and Baekto. The design of the accelerated weathering test considered the domestic climate characteristics and the location of Dancheong. Outdoor weathering tests were conducted at the Research Institute in Daejeon and the Sungnyemun Gate in Seoul to confirm the field reproducibility of the accelerated weathering test. Monitoring of the physical changes in pigments through accelerated and outdoor weathering tests are based on ultraviolet exposure dose. Despite small cracks at the beginning of the tests, the monitoring showed that Seokganju and Baekto had no marked physical changes, but the surface cracks of Jinsa and Seorok continue to expand. Hwangto and Noerok were marked with water or were resin stained, and the particles of Jahwang, Wunghwang, and Seokcheong had lost their luster. Despite the absolute difference in color change in each test, the final chromaticity change patterns of pigments were similar in that the color difference between Baekto and Noerok was below five, and Jina was above 28. The physical and surface color pigment changes were more concentrated in outdoor weathering tests than in accelerated tests, and the Seoul site was more intense than the Daejeon site. This is because outdoor weathering tests are exposed to severe variations of temperature and moisture or deposition of dust particles and, in the case of Seoul, the site is more exposed to the external environment than the Daejeon site.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.5
• /
• pp.785-808
• /
• 2016

The objective of this study was to investigate the effect of the short-term weathering on the flame retardant performance of wood coated with Dancheong. Flame retardants were applied on the Dancheong coated Korean red pine. Flame retardants applied panels were layed at the two conditions of outdoor exposure and artificial aging to assess the reliability of artificial aging. Flame retardants used were commercial products developed for historical wooden buildings. Scanning electron micrographs revealed the forming of carbonized membrane by melting of flame retardant on wood surface. These carbonized membranes may help delay the further combustion of wood. Flame retardant performance was assessed by measuring heat release rate (HRR) and total heat release (THR) by cone calorimetry. There was no difference in flame retardant performance between before and after 6-month outdoor exposure tests. And also no difference in flame retardant performance between before and after 2-week artificial aging which corresponds to 6-month outdoor exposure. Both tests showed the similar results of combustion characteristics.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.147-148
• /
• 2015

Exposed type waterproofing PVC sheets installed on structure rooftops are subject to changes in physical properties after longterm exposure to sunlight. Particularly when consideration the rotational movement of sunlight over the day through the course of the sun rising from the east and setting in the west, in the case of flat roofs the amount of UV ray the the surface of the PVC waterproofing sheet receives may be even throughout, but in cases of slanted rooftops the sunlight exposure may be uneven across the surface. In this regard, this study examines the effect uneven sunlight exposure on the exposed type waterproofing PVC sheets installed on slanted rooftops.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.279-287
• /
• 2018

Sealants are an important element of modern architecture and serve as a building protection against weathering by providing barriers against ingress of moisture, air, and other materials. Exposure to a variety of environments often reduces lifespan due to changes in physical, chemical and mechanical characteristics, and UV, humidity, and temperature expansion are important issues that are directly related to durability. In this study, a combined deterioration test chamber was developed to simulate the environment of the open air as an instrument for verifying the durability of structural sealing materials indoors. In order to replicate special weather conditions, such as yellow dust, acid rain, and contamination by microorganisms, it was deemed impossible to replicate the outdoor environment by 100 %, and the results of the results of the results of the external exposure test of the structural sealant and the combined deterioration testing device. As a result of the displacement test of the outdoor exposure test, it was determined that the sealant was breaking apart and that it would be smooth, and the displacement would be up to three times greater than the initial material value of 1 year. The displacement test results of the combined deterioration test device show the tendency to deteriorate, decreasing the elasticity and tensile characteristics. In the case of denatured silicon, the current 400 cycles have been completed to confirm 12 months of degradation of the external exposure. The deformation of the test specimen cannot be verified with the naked eye, so it is considered that the conditions of the specimen are more stable than the silicon sealant. As a result of the outdoor exposure test, if the combined deterioration test device is structured and proposed in the relevant guidance or specification, the anticipated lifespan of 12 months in the actual use environment can be verified indoors and below 3 months later, economically.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.69-70
• /
• 2017

In Korea, silicone type sealant is widely used for construction site. Before the silicone type, urethane type is one of the main type sealants. However, the weathering property is less than the silicone type, the urethane type is replace by the silicone one. Still the urethane type is used for the inside of the buildings for the perimeter of the window. The silicone type sealants are better in weathering property than those of the urethane type sealants. Except the weathering property urethane type sealant has its own advantage like movement property, low cost and so forth. There are many research results for the outdoor weathering of the sealants, but in Korea there are no results for the outdoor weathering for construction sealants. This research is focused on the outdoor weathering of the urethane sealants, how to measure the degradation, and compare the products which used in Korea. The outdoor weathering test is usually time consuming, thus we designed specialized device for accelerating the result.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.05a
• /
• pp.45-47
• /
• 2011

Finishing materials used during the construction of reinforced concrete structures aid in providing resistance to carbonation and help ensure the durability of a structure. However, detailed examinations of this phenomena using data gained from long-term outdoor exposure are not only lacking, but also are not taken into account as factors affected by the local environment. In this research, the velocity coefficient in terms of carbonation is compared as a difference according to the local region and the averaged annual temperature, and the carbonation-preventive effects of finishing materials are analyzed. As an outcome of this study, the results of long-term carbonation can be evaluated from carbonation resistance R induced by an acceleration carbonation test.

• Journal of Conservation Science
• /
• v.32 no.4
• /
• pp.491-500
• /
• 2016

Fog is atmospheric in which tiny drops of water vapor are suspended in the air near the ground. Its form, occurrence, etc., change according to the temperature, relative humidity, wind and geographical features of the space around it. In particular, fog tends to occur near a source of water because of temperature and relative humidity difference. These days, climate change is increasingly affecting the occurrence of fog. Therefore the purpose of this study was to investigate how fog affects materials that are part of our cultural properties through outdoor exposure tests and artificial degradation. The degradation evaluation of materials as a function of fog occurrence frequency, showed that the color of metals changed noticeably, whereas dyed silk and Dancheong showed degradation on the surface and color differences but no particular tendencies. Therefore, damage prediction by color differences as a function of fog occurrence frequency was based on metal samples, which showed constant color differences. Through a comparison of the predictive value and color difference by outdoor exposure, the accuracy and applicability of the damage prediction formula was confirmed. If a more complex damage prediction formula is created, it is expected that prediction of the degree of material damage in the field would be possible.

• Proceedings of the Korean Reliability Society Conference
• /
• 2002.06a
• /
• pp.157-164
• /
• 2002

본 연구에서는 실생활에 응용되는 Chloroprene계 고무에 대하여 30개월 동안 옥외 폭로를 행하였으며 동시에 Xenon-arc Type의 촉진 내후성시험기를 이용하여 그에 따른 내후성의 변화를 평가하였다. 폭로기간에 따른 인장강도와 신장률의 변화를 측정하였고 폭로면의 표면층에 대하여 FT-IR과 SEM을 사용하여 화학적 특성 및 미세구조를 분석하였다. 태양복사와 습도에 노출된 고무의 표면은 매우 짧은 기간에 파괴되었고, 고무 내부에 존재하는 가교제들의 용출을 확인할 수 있었으며, 산소와의 결합으로 내부층보다 고무의 표면에서 더 많은 가수분해와 광분해가 이루어진다는 것을 확인할 수 있었다. 이와 같은 표면층의 변화와 파괴는 고무의 기계적 성질에도 의미 있는 영향을 주었다.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.04a
• /
• pp.176-177
• /
• 2022

In this study, surface performance evaluation was conducted according to the fiber and surface finishing technique of the exterior material using Ultra High Performance Concrete(UHPC), whitch is spotlighted as a highly durable exterior material. As a result of outdoor exposure, the initial performance of the UHPC Panel using organic fibers was maintained without being affected by the surface finishing technique. In the specimen using steel fiber, the surface performance was maintained when the water repellent treatment was performed in the plain specimen, but fiber corrosion occurred in the specimen to which the surface finishing technique was applied.