• 한국화재소방학회논문지
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• 제24권1호
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• pp.95-102
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• 2010

본 연구에서는 목조한옥구조 적심부 실물화재 실험을 통하여 목조건축문화재 지붕 상부구조 내부의 연소특성을 분석하였다. 실험체는 숭례문 지붕 내부 구조의 특성을 고려하여 제작하였으며, 기와를 제외한 강회, 보토, 적심, 개판 순으로 구성하고 위치별로 열 측정 장치를 설치하였다. 첫 번째 실험은 목조건축 문화재의 적심 지붕구조를 가지는 경우 연소 및 화재 성상을 알아보았다. 두 번째 실험은 화염이 직접 접촉하는 서까래와 천정 개판 상 하부에 방염도료를 도색하여 방염도료 내화 성능을 알아보았다. 세 번째 실험은 적심부와 개판 사이에 방염천을 넣어 적심부 및 강회층에 화염 전파에 어떤 영향을 미치는지 알아보았다. 그 결과 목조 한옥구조 지붕의 적심부 화재 전파는 외부 화염의 제거 후에도 내부에 장시간에 걸쳐 연기와 화염이 계속 진행함을 보였다. 또한, 방염도료의 경우 내열효과를 보였으며, 방염천의 경우 화염전파온도를 $100^{\circ}C$ 이하로 유지할 때 적심부로부터 화염전파차단 효과를 보였다.

• 한국산업보건학회지
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• 제33권4호
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• pp.464-470
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• 2023

Objectives: This study evaluated occupational exposures to noise and heat stress during routine non-outage works in three coal-fired power plants in the Republic of Korea. Methods: The data were collected during the summer of 2020. Full shift noise exposure of 52 workers were measured using noise dosimeters. Heat stress of 16 worksites were measured for 70 minutes using wet-bulb globe temperature monitors. Results: The noise dosimetry results revealed time-weighted averages that ranged from 47.5 to 88.9 dBA. 2 out of 52 noise measurements exceeded 85 dBA. Based on the arithmetic mean, the coal service group showed the highest level at 80.2 dBA by job tasks. Noise exposures exceeding 85 dBA were measured in the coal service and plant operator group. Heat stress index measurements ranged from 20.3℃ to 37.2℃. 1 out of 9 indices measured in coal facilities and 4 out of 7 indices measured in boiler house exceeded 1 hour TWA during moderate work. Heat stress indices measured from boiler houses were significantly higher than those measured from coal equipment. Conclusions: The results show that overexposure to noise and heat stress may be encountered during routine non-outage work activities in coal-fired power plants. Appropriate actions should be taken to reduce future health outcome from occupational exposure to noise and heat stress in the industry.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권3호
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• pp.127-131
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• 2005

Big fire such as mountain fire may cause the prevention of the functions of the overhead cables and insulators, which may affect the operation of the transmission lines. In the worst case, this kind of disaster may have a huge effect on the whole industry of a country. However, the study on the effect of the mountain fire on the transmission line is very rare. Therefore, in order to understand the effect of the mountain fire on the polymeric insulator for transmission lines, the author observed the deformation of the sheds of the polymeric insulators and the change of the discs of the porcelain insulators under fire, varying the ignition time using the artificial ignition testing equipment which simulates the mountain fire, and investigated the electrical and mechanical characteristics of the insulators after the ignition test. For the test, the miniature insulators made of polymeric material and porcelain have been utilized. As the result, the following conclusions were obtained. First, the porcelain insulator was degraded in electrical characteristics when the insulator was subjected to the fire for approximately 5 minutes; whereas, the polymeric insulator was not degraded though there were some damage on its sheds. Second, after 20 minute exposure to the fire, the polymeric insulator lost a lot of parts of sheds, but the electrical characteristics was lowered by around $20\%$, but the porcelain insulators were electrically degraded by more than $80\%$.

• Computers and Concrete
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• 제24권3호
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• pp.249-258
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• 2019

In order to investigate the strength recovery of fire-damaged concrete after post-fire curing, concrete specimens were heating at $2^{\circ}C/min$ or $5^{\circ}C/min$ to 400, 600 and $800^{\circ}C$, and these exposed specimens were soaked in the water for 24 hours and following by 29-day post-fire curing. The compressive strength and split tensile strength of the high-temperature-exposed specimens before and after post-fire curing were tested. The proportion of split aggregate in the split surfaces was analyzed to evaluate the mortar-aggregate interfacial strength. After the post-fire curing process, the split tensile strength of specimens exposed to all temperatures was recovered significantly, while the recovery of compressive strength was only obvious within the specimens exposed to $600^{\circ}C$. The tensile strength is more sensitive to the mortar-aggregate interfacial cracks, which caused that the split tensile strength decreased more after high-temperature exposure and recovery more after post-fire curing than the compressive strength. The mortar-aggregate interfacial strength also showed remarkable recovery after post-fire curing, and it contributed to the recovery of split tensile strength.

• Structural Engineering and Mechanics
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• 제82권2호
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• pp.163-172
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• 2022

Zinc-rich epoxy (ZRE) is used to overcome corrosion problems in reinforced concrete (RC) beams and coat steel rebars to protect them from humidity and chlorides. An extra coating layer of Sikadur-31 epoxy (SDE) is utilised to increase bond strength because the use of ZRE reduces the bond strength between concrete and steel rebars. However, the low melting point of SDE indicates that concrete specimens are vulnerable to fire. An experimental investigation on flexural performance of RC beams incorporating ZRE-SDE coating of steel rebars that were destroyed by fire is performed in this study. Twenty beams of five concrete mixes with different cementitious contents were tested to compare fire exposure for coated and uncoated rebars of the same beams at room temperature and determine the optimal cementitious content. Scanning electron microscopy (SEM) was also applied to investigate characteristics of fired mixture samples. Results showed that the use of SDE-ZRE at room temperature improves flexural strengths of the five mixes compared with uncoated rebars with percentages ranging from 8.5% to 12.3%. All beams with SDE-ZRE lost approximately 50% of their flexural strength due to firing. Moreover, the mix incorporating SF (silica fume) of 15% and cement content of 400 kg/m³ introduces optimum behaviour compared with other mixes. All results were supported and verified by the SEM analysis and compressive strength of cubic specimens of the same mixes.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 산업계
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• pp.135-141
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• 2009

This technology is able to construct with hardening UREPALT adhesives and TPO URE-Sheet simultaneously using automatic equipments. the benefit of this construction method is that The layer of waterproofing is uniform and defect of construction would be reduced because of no construction joints between UREPALT adhesives and TPO URE-Sheet. Furthermore, this new method could accomplish shortening of construction period, quality control and saving of labor costs. Also the non-exposure waterproofing method would be protected from fire and safe for workers without using a torch.

• Communications for Statistical Applications and Methods
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• 제9권2호
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• pp.381-388
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• 2002

It has been pointed out that the classical credibility model used in Korea since the beginning of 1990's lacks in objectiveness. Recently, in order to improve objectiveness, the empirical Bayes credibility model utilizing general exposure units like the number of claims and premium has been employed, but that model itself is not quite applicable in the country like Korea whose annual and classified empirical data are not well accumulated and even varied severely. In this article, we propose a new and better model, Based on the new model, we estimate both credibility and loss ratio of each class for fire insurance plans by Korean insurance companies. As a conclusion, we empirically make sure analysis that the number of claims is a more reasonable exposure unit than premium.

• 대한임상독성학회지
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• 제6권2호
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• pp.117-122
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• 2008

Purpose: Surveys on poisoning usually involves intoxication rather than inhalation, skin contact, etc. Therefore, we examined the characteristics of patients who visited the emergency department in an industrial complex after acute industrial exposure to toxic materials. Methods: Medical records of patients exposed to toxic materials in the work places from April, 2006, to March, 2008, were analyzed retrospectively. Inhalation patients due to fire were excluded. Results: Subjects included 66 patients, with a mean age of $35.4{\pm}10.9$ years, mostly men (91%). Toxicity occurred in 51 patients (77%) by contact, 15 patients (23%) by inhalation, and none by oral ingestion. For toxic materials, 10 patients were exposed to hydrofluoric acid, 8 to hydrochloric acid, 7 to sodium hydroxide, 7 to metals, and others. The face and hands were the most frequent exposure site by contact. Most exposures were caused by accidents, with 29 cases (42%) exposed because of carelessness or not wearing protective equipment. Most complaints were pain on exposure site, but 7 of the inhalation patients complained of dyspnea. The majority of patients with contact exposure were discharged after wound care or observation. After inhalation exposure, 1 patient died and 5 patients were admitted to the intensive care unit. Conclusion: Major causes of workplace exposure were not wearing protective equipment or carelessness. Although contact exposures are usually benign, cautious observation and management are required in patients with inhalation exposure.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2011년도 추계학술논문발표회 논문집
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• pp.167-170
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• 2011

화재현장에서 소방공무원은 화염, 증기, 또는 고온물 등에 의하여 화상사고를 당하고, 이로 인하여 극심한 고통 받고 있다. 따라서 화상 예측에 대한 연구를 통해 화상을 방지할 수 있는 방법을 개발하여야 한다. 본 연구에서는 화재시 고온 열유속 조건하에서의 화상 발생에 대한 예측을 수치해석적 방법으로 수행하였다. 생체 열전달 방정식(Bio-heat transfer)을 이용하여 지배방정식을 유도하였으며, 유한차분법(Finite Difference Method)을 활용하여 피부조직에 대한 온도분포를 얻었다. 이를 바탕으로 한 손상함수를 이용하여 2도 화상의 발생 유무를 예측하였으며, 기존의 실험 결과[Stoll and Chianta]와 비교하여 좋은 예측 결과를 얻을 수 있었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.81-82
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• 2018

The structure of the RC structure is actively reinforcing the structure of the building which has suffered from aging, artificial and natural damage of the building. Among various reinforcement methods, epoxy adhesive is used to attach FRP in FRP reinforcement method which is reinforcing by attaching FRP to the structural part. At this time, the epoxy adhesive having a low critical temperature has a sudden adhesive failure upon exposure to heat, and thus, the development of an inorganic fireproof adhesive having a high critical temperature has progressed. Therefore, in this study, the compositional change of inorganic fire - resistant adhesive exposed to high temperature heat was analyzed by XRD.