• Journal of the Korea Institute of Building Construction
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• v.24 no.3
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• pp.297-308
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• 2024

This study presents a novel approach for evaluating fire-induced damage depth in concrete. The methodology leverages the principle that exposure to high temperatures causes internal expansion within concrete, leading to increased voids and microcracks in the damaged zones. This heightened porosity results in greater absorption rates compared to undamaged areas. By immersing fire-damaged concrete samples in water and subsequently monitoring the drying process, the depth of damage can be assessed. Differences in drying rates and color variations between damaged and undamaged areas serve as visual indicators for determining the extent of the damage. Experimental results from this water immersion method revealed damage depths of 38.7mm and 37.5mm for two different concrete mixtures. These measurements notably surpass the damage depths estimated using traditional phenolphthalein-based methods. This discrepancy suggests that utilizing the absorption rate principle, which is directly linked to the physical changes caused by thermal expansion, offers a more accurate and sensitive assessment of fire damage depth compared to methods relying solely on the presence of Portlandite for colorimetric indication.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1045-1048
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• 2010

본 연구는 LPG 충전소 등에서 운용하는 저장탱크에 대하여 퓨방법을 통하여, 기존의 지상형과 지하형의 장점과 단점을 비교 판정하여 혁신시공법으로 고객만족을 실현시키기 위함이다. 자동차 연료로서 LPG(Liquefied Petroleum Gas)의 사용은 대기오염을 줄이는데 효과적으로 사용이 빠르게 확산되고 있다. 하지만 가스사용이 늘어나면서 폭발과 화재에 의한 인명피해가 해마다 발생하고 있으며, 특히 대규모 저장시설에서의 가스사고는 사회적으로 심각한 문제를 야기하고 있다. 따라서, 본 연구는 LPG를 대량으로 취급 저장하는 시설에서 운용하는 저장탱크의 설치방법을 개선하기 위하여 아이디어 판단기법중 하나인 퓨(Pugh) 방법으로 판단하면 기존의 지상형과 지하매몰형, 지하격납형에서 안전성과 토지이용률이 우수한 지하격납저장탱크가 가장 효과적임을 알 수 있다.

• Fire Science and Engineering
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• v.26 no.3
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• pp.35-39
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• 2012

This paper analyzes the combustion diffusion pattern when a water purifier is artificially ignited outside and inside in order to provide data to examine the cause of fire of a water purifier damaged by fire. The analysis result of the combustion diffusion pattern of a water purifier shows that the combustion diffused at a higher speed when it was ignited inside the purifier than when ignited outside. It took approximately 360 seconds for the water purifier to be half-burned when ignited on the outside, and approximately 180 seconds when ignited from inside. That is, it is thought that the internal combustion speed is higher because the internal ignition causes the generated heat to be accumulated and radiated instantly. It was observed that the water purifier damaged by fire caused by external ignition showed a uniform carbonization pattern and the carbide burned down at the bottom were gradually deposited. The water purifier damaged by internal ignition showed a relatively clear boundary of carbonized surface, which formed a V-pattern. The difference in the combustion patterns presents an objective base from which to determine where the fire started. By the time the purifier was half-burned by fire, the built-in fuse had not melted and the power supply protection device did not operate. In addition, as was found in the case of the fuse damaged by a general fire, carbonization occurred at the metal holder, and it is thought that this fact may be used as a basis from which to determine the cause of a fire.

• Fire Science and Engineering
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• v.24 no.5
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• pp.136-141
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• 2010

The purpose of this study is to examine the structure and heat generation mechanism of low voltage switches used to turn on or off the power supply to an indoor lighting system and investigate how the fixtures and movable contacts of the switches are damaged depending on the types of energy sources in order to secure the judgment base for expected PL disputes. Based on the Korean Standard (KS) testing method for incombustibility, this study applied a general flame to the switch. In addition, current was supplied to the switch using the PCITS (Primary Current Injection Test System). The ambient temperature and humidity were maintained at $22{\pm}2^{\circ}C$ and 40~60% respectively while performing the test. It is thought that the switch generated heat due to a defective connection of the wire and clip, insulation deterioration and defective contact of the movable contact, etc. The surface of the switch damaged by the general flame was uniformly carbonized. When the flame source was removed, the fire on the switch was extinguished naturally. From the result obtained by disassembling the switch carbonized by the general flame, it could be seen that fixtures and movable contacts remained in comparatively good shape but the enclosure, clip support, movable contact, indicating lamp, etc. showed carbonization and discoloration. In the case of the switch damaged by overcurrent, the clip connecting the wires, clip support, etc. showed almost no trace of damage, but the fixtures, movable contact, indicating lamp, etc. were severely carbonized. That is, the sections with high contact resistance were intensively damaged and showed a damage pattern indicating that carbonization progressed from the inside to the outside. Therefore, it is possible to judge the initial energy source by analyzing the characteristics of the carbonization pattern and the metal fixtures of damaged switches.

• Fire Science and Engineering
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• v.34 no.1
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• pp.135-141
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• 2020

The first case of Middle East Respiratory Syndrome (MERS) was reported in Korea in 2015, after a Korean man from Bahrain tested positive for the infection. After first eruption, there were numbers of secondary infectees and whole country were frightened. At the time, isolated ambulances were available but few, and there was no specific way to prevent contamination during transfer. Therefore, Seoul National University Hospital and the University of Seoul developed isolation units and air filters. Four years after the MERS outbreak, this study measured the differential pressure inside and outside the small isolation units based on the differential pressure and air flow derived from simulation and testing, and proposed minimum values for virus leakage and internal sealing. A performance evaluation and testing method for the transfer equipment is proposed. The critical function of the small isolated transport equipment was defined and selected as an evaluation item; performance evaluation was carried out by simulating a real-world case. The results provide the proper pressure configuration of positive and negative pressure inside the segregation feeder; the clear criteria for the HEPA filter; and the performance criteria for the segregation feeder and air purifier.

• Fire Science and Engineering
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• v.33 no.5
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• pp.66-77
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• 2019

To secure the safety and improve the work efficiency of forest firefighting crews, performance evaluation criteria for safety helmets were developed in this study. Because the standards for forest firefighting safety helmets are not available in Korea, we began our study based on the standards for firefighting safety helmets used by the Korea Fire Institute (KFI). Eleven test items were selected excluding 15 other items out of the 26 test items that, through the consultation of stakeholders and the review of foreign standards, were initially included in our study. Two types of general safety helmets and one firefighting helmet were tested by applying KFI standards, and the results were compared. The general safety helmets did not meet the standards of the retention system and chin strap. Additionally, polyethylene and acrylonitrile butadiene styrene materials were found to be especially weak under heat conditions. We compared the criteria of KFI, International Standardization Organization (ISO) 16073, National Fire Prevention Association (NFPA) 1977, NFPA 1971, and British Standards European Norm (BS EN) 443, and finally selected 11 test items and their acceptance criteria suitable for the work environment of forest firefighting crews in Korea.

• Fire Science and Engineering
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• v.32 no.6
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• pp.74-83
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• 2018

In order to secure safety and improve work efficiency of forest firefighting crews, performance evaluation criteria for safety gloves were developed. Since the standard for forest firefighting safety gloves is not available in Korea, we started the study based on the standard for firefighting safety gloves operated by KFI. 12 test items were selected excluding 5 test items out of the 17 test items through the consultation of stakeholders and the review of foreign standards. Two types of general safety gloves used by forest firefighting crews and one firefighting gloves were tested by applying KFI standard and the results were compared. Materials such as nylon or polyurethane which are weak to fire are not suitable for forest firefighting safety gloves. We compared the criteria of KFI, ISO 16073, NFPA 1977, NFPA 1971 and BS EN 659, and finally selected 12 test items and acceptance criteria suitable for the work environment of forest firefighting crews in Korea.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.77-77
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• 2013

최근의 산업활동에서는 신규 원료 개발과 생산 효율성을 높이기 위하여 분체 공정이 증가하고 있는데, 미세 분진의 취급으로 분진운의 형성과 착화가 용이해지므로 분진폭발이나 화재 위험성이 증가하고 있다. 분진을 안전하게 사용하고 저장, 취급하기 위해서는 착화 전의 위험성 지표로서 최저발화온도(MIT ; Minimum Ignition Temperature)를 사전에 파악해 두는 것이 중요하다. 분진농도의 발화온도는 장치 내의 발화위험성이나 분진 취급 공정의 사고예방대책 관리를 위한 실용적 관점에서 중요하게 활용되는 폭발특성값이다. 또한 분진의 발화온도는 분진농도에 의존하며 농도변화에 따른 가장 낮은 온도를 MIT라고 한다. 본 연구에서는 화재폭발사고 빈도가 줄지 않고 있는 Mg 및 Mg-Al합금(60:40 wt%, 50:50 wt%, 40:60 wt%)을 대상으로 조성비율에 따른 최저발화온도를 실험적으로 조사하였다. Mg 및 Mg-Al(60:40 wt%), Mg-Al(50:50 wt%), Mg-Al(40:60 wt%) 시료의 평균입경은 142, 160, 151, $152{\mu}m$이다. MIT실험장치는 IEC 61241-2-1(Methods for Determining the Minimum Ignition Temperatures of Dust, 1994)에 준거하여 제작하여 사용하였다. 실험장치는 가열로, 분진운 시료홀더, 온도조절장치, 압축공기 제어장치 등으로 구성되어 있다. 구체적인 실험방법은 시험분진를 분진홀더에 장착하고 0.5 bar의 압축공기를 0.3 sec 동안 사용하여 일정 온도로 가열된 로의 내부로 분진운을 부유시킬 때에 분진운이 발화하여 가열로 하단부의 개방구에까지 화염이 전파하는지를 디지털비데오카메라로 기록, 평가하여 발화 유무를 판정하였다. Mg합금에 대한 MIT를 측정한 결과 $740^{\circ}C$가 얻어졌으며, Mg-Al(60:40 wt%)의 MIT는 $820^{\circ}C$로 조사되었다. 그러나 Mg-Al(50:50 wt%) 및 Mg-Al(40:60 wt%)에 대해서는 최대 가열로의 설정온도를 $890^{\circ}C$까지로 하여 농도를 변화시키면서 조사하였으나 발화가 일어나지 않았다. 문헌에 따르면 Mg입자 표면의 산화피막은 다공성으로 일정 온도에서 산화반응이 시간에 따라 직선적으로 증가하는데 반하여, Al의 산화피막은 보호 작용을 하여 일정 온도에서 산화반응속도가 표면과 내부의 농도 기울기에 의한 확산속도에 의존한다고 보고하고 있다. 본 연구결과를 토대로 Mg-Al합금의 발화특성을 고찰해 보면, Mg-Al합금에서 자기 전파성이 작은 Al성분의 증가는 착화지연이 증가하여 연소성이 감소하여 최저발화온도의 증가로 이어지는 것으로 추정되었다. 또한 발화온도는 주어진 조건의 온도장에서 분진이 존재하는 시간 길이에 따라 변화하므로, 발화온도를 실험적으로 측정하는 경우에는 측정장치나 방법에 따라 달라지므로 사업장의 현장에 발화온도를 적용하는 경우에는 장치 내의 분진의 존재시간을 고려할 필요가 있다.

• Journal of the Society of Disaster Information
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• v.14 no.1
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• pp.89-100
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• 2018

when the explosive wastes to be treated as designated wastes are brought into the wastes treatment plant by mistake and lead to an explosion in the wastes disposal process, many people and property damage are involved. Waste should be treated properly. As mentioned in this paper, ignition reac- tion tests of ignitable re-burning of explosives packing material waste (solid butadiene) confirmed that ignition was easily occurred, and that even small ignition sources were easily ignited and burned quickly and explosively. In particular, when explosives are loaded into incineration wastes in large quantities and mixed with organic compound wastes, such as fire and explosion accidents caused by explosives packing materials at waste disposal sites, flammable and oxidative gases are generated due to mutual oxidation and pyrolysis It is confirmed that there is a possibility that ignition sources such as spark ignite and instantaneously lead to explosion. It is hoped that this study will be a small reference for on - site detection in the field of fire, and it is expected that the fire - fighting agency will be recognized as a fire investigation agency and will contribute to the improvement of the credibility.

• Congress of the korean instutite of fire investigation
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• 2010.12a
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• pp.63-79
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• 2010

It is found to the arc trace on the junction termination of 345kV cable. According to the analysis of the cable material is judged to be good. Manufacturing and design problems are not considered. In construction defects, it was estimated to the low level of insulation oil. In the majority of the arc trace appeared XLPE is found. However, there is no Soots mark, yellow band has not been confirmed, not associated with a radial arc of the spider leg is not evidence. In other opinions, void, contamination or jut are not found on the inside of XLPE. Thus, by the attachment of the impurities in surface of XLPE insulation is judged to the breakdown.