• 한국화재소방학회논문지
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• 제24권2호
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• pp.44-51
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• 2010

본 연구의 목적은 성능적 내화설계를 기반으로 한 CFT 구조의 내화성능 설계기술 개발을 최종목표로 CFT 구조의 실증적 실험을 통한 내화성능을 도출하고 내부 콘크리트 압축강도와 하중비를 변수로 하여 수축량과 시험체 내부 온도를 측정하여 내화성능을 도출하여 성능설계를 위한 기초 자료로 활용하고자 하는데 있다. KS F 2257-1과 7의 기준에 따라 CFT 각형 기둥에 24MPa, 40MPa, 하중비 0.9, 0.6, 0.2를 재하하여 내화성능기준에 따른 결과 하중비 변화는 24MPa의 경우 하중비가 0.3 감소시 약 73분의 내화성능 향상효과가 있는 것으로 나타났다. 40MPa은 하중비 0.6, 0.2의 경우 내화성능시간은 31분, 180분으로 나타났다. 시험체 내부 콘크리트 강도 변화에 따른 내화성능평가 결과 강도가 증가할수록 내화성능은 감소하는 것으로 나타났다.

• 복합신소재구조학회 논문집
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• 제3권2호
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• pp.36-46
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• 2012

Structure Insulated Panel (SIP) is an wooden structure material with which structure and insulation functions are satisfied. Hence, it would be a cost-effective model to implement low energy house which has higher insulation and structure performance and which the wall thickness is able to be reduced. In this study, performance of thermal insulation and fire resistance were evaluated in order to verify applicability to low energy house. Fire resistance test is performed on vertical load bearing members for partitions, and the test results satisfy one hour of fire resistance condition according to KS F 2257. The members include two layers of fireproof gypsum board with thicknesses of 12.5mm attached to SIP. Thermal insulation performance is satisfied with the 2012 standard ($0.225W/m^2{\cdot}K$). As the performance of resistance and thermal insulation are satisfied, SIP is expected to be applied to low energy building materials. In the future, the structural safety will be confirmed by structural performance and seismic performance test and the guidelines for distribution will be drawn up.

• 국제초고층학회논문집
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• 제12권3호
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• pp.235-239
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• 2023

In this study, the fire resistance performance of the concrete-filled steel tube (CFT) columns and thin steel-plate composite (TSC) beams installed at a 20-story office building were designed using a performance-based structural fire design. Because of the lack of any specific provisions in the building code and guidelines for structural engineers about the performance-based approach, the only prescriptive approach has been selected for designing fire-resistant structures in Korea. To evaluate the fire resistance performance of the CFT columns and TSC beams, finite element analysis verified by the experimental results studied by several researchers was conducted with ABAQUS. From the fire scenario, the temperature distributions of the CFT columns and TSC beams were found via finite element analysis and the behaviors of the CFT columns and TSC beams were investigated in the structural field based on the temperature distribution.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.41-42
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• 2023

The physical performance of high-strength concrete deteriorates when exposed to high temperatures such as fire. In particular, in the case of ultra-high-strength concrete, there is a high possibility of explosion due to internal water pressure and thermal expansion due to the tight internal structure. In this paper, a fire resistance certification test was conducted for field application of ultra-high-strength fire-resistant concrete, and the fire resistance performance (temperature rise of main rebar) was compared according to the structural concrete cover thickness. As a result, when the covering thickness was 40 mm, three structures did not meet the certification standards, and when the covering thickness was 50 mm, all structures met the fire resistance certification standards.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2002년도 학술논문발표회
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• pp.47-50
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• 2002

This paper presents the results of fire resistance properties of high performance concrete varying with fiber kinds and the size of metal lath in order to verify the validities of fiber on the spatting resistance by fire. Metal lath, glass fiber and carbon fiber are used to confine the concrete. According to test results, plain concrete without lateral confinement and confined concrete with glass fiber and carbon fiber show entire failure after exposed to fire, while confined concrete with metal lath take place in the form of slight surface spatting by fire, which has favorable spatting resistance of concrete. As for the effect of the size of metal lath, when the size of metal lath is more than 1.2mm of thickness, the residual strength of concrete exposed to fire maintains more than 80% of its original strength. However, glass fiber and carbon fiber does not perform desirable spatting resistance by fire due to loss of lateral confinement of fiber exposed to fire caused by melting of fiber and reducing bond strength between concrete and fiber.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.463-468
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• 2001

A lot of considerations on the spatting by fire of high performance concrete should be taken into for fire resistance of the concrete structures. In this paper, fire resistance of high performance concrete is described using polypropylene fiber, which is known to be contributed to fire resistance. Strength level and member size are varied with. According to test results, spatting by fire takes place more easily, as W/C increases and member size decreases. It shows that concrete containing polypropylene fiber has good effects on preventing spatting by fire. In case high performance concrete does not contain polypropylene fiber, residual strength shows to be decreased remarkably compared :o that of normal concrete. Whereas, in case 0.1% of polypropylene fiber contents, high performance concrete shows higher residual strength than that of normal concrete. As member size is smaller, residual strength shows to be decreased.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2010년도 춘계학술논문발표회 논문집
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• pp.389-394
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• 2010

A concrete filled square steel tube (CFT) is composed of the external steel material, which its strength is reduced in fire due to sudden temperature increase, and the internal concrete with high thermal capacity that can ensure the fire resistance performance of the structure. Therefore, research about the influence factors of the structural performance of CFT column is required in order to apply CFT column to a fire resisting structure, and additional research about influence for each condition is also necessary. Among the influence factors, the boundary condition between column and beam is important structurally, and it is one of the major factors that determine overall fire resisting performance. This study performed a fire experiment under loading in order to analyse the influences of CFT column to the boundary condition. As the results of the experiment, fire resistance time of 106 minutes was ensured for the clamped-end condition but 89 minutes for the hinge-end condition in case of the 360 cross section. And, fire resistance time of 113 minutes was ensured for the clamped-end condition but 78 minutes for the hinge-end condition in case of the 280 cross section. The difference in the fire resistance performance according to changes in the boundary conditions showed a tendency that larger change effect on the fire resistance performance was derived from smaller cross section area.

• 한국화재소방학회논문지
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• 제24권6호
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• pp.104-111
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• 2010

CFT기둥은 강관내부에 콘크리트를 채워 넣은 구조로서, 화재 시 강관의 강도는 저하되나 내부 콘크리트의 높은 열용량 효과로 내화성능을 확보할 수 있는 구조이다. 본 연구에서는 강관내부의 충전된 콘크리트의 압축강도 및 축력비 변화에 따른 CFT기둥의 내화성능을 평가하였다. 내화성능의 평가는 KS F 2257-1 및 KS F 2257-7에 따라 수행되었으며, 적용 부재 단면은 $280{\times}280{\times}6$, 콘크리트 압축강도 24MPa, 40MPa 및 축력비 0.9, 0.6, 0.2를 실험변수로 설정하였다. 재하가열시험을 통한 내화성능평가 결과, 콘크리트 압축강도 24Mpa의 경우 축력비 0.9, 0.6, 0.2에서는 각각 27분, 113분, 3시간 이상으로 나타나 축력비 변화에 따른 내화성능이 크게 변화하는 것으로 나타났다. 콘크리트 압축강도 40MPa의 경우, 축력비 0.9, 0.6에서는 각각 19분, 28분으로 나타났다. 40MPa는 24MPa에 비해서 축력비 변화에 따른 내화성능 향상 효과는 크지 않은 것으로 나타났다. 이는 고강도의 경우 가열시 발생되는 내부 압력의 상승로 성능저하가 크게 발생되는 것으로 판단되었다.

• Steel and Composite Structures
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• 제15권1호
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• pp.103-130
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• 2013

Fire performance and fire safety of high-rise buildings have become major concerns after the disasters of World Trade Center in the U.S. in 2001 and Windsor tower in Spain in 2005. Performance based design (PBD) approaches have been considered as a better method for fire resistance design of structures because it is capable of incorporating test results of most recent fire resistance technologies. However, there is a difficulty to evaluate fireproof performance of large structures, which have multiple structural members such as columns, slabs, and walls. The difficulty is mainly due to the limitation in the testing equipment, such as size of furnace that can be used to carry out fire tests with existing criteria like ISO 834, BS 476, and KS F 2257. In the present research, a large scale calorie meter (10 MW) was used to conduct three full scale fire tests on medical modular blocks. Average fire load of 13.99 $kg/m^2$ was used in the first test. In the second test, the weighting coefficient of 3.5 (the fire load of 50 $kg/m^2$) was used to simulate the worst fire scenario. The flashover of the medical modular block occurred at 62 minutes in the first test and 12 minutes in the second test. The heat resistance capacity of the external wall, the temperatures and deformations of the structural members satisfied the requirements of fire resistance performance of 90 minutes burning period. The total heat loads and the heat values for each test are calculated by theoretical equations. The duration of burning was predicted. The predicted results were compared with the test results, and they agree quite well.

• 한국해양공학회지
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• 제37권3호
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• pp.99-110
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• 2023

When a fire accident accompanied by an explosion occurs, the surrounding firewalls are affected by impact and thermal loads. Damaged firewalls due to accidental loads may not fully perform their essential function. Therefore, this paper proposes an advanced methodology for evaluating the fire resistance performance of firewalls damaged by explosions. The fragments were assumed to be scattered, and fire occurred as a vehicle exploded in a large compartment of a roll-on/roll-off (RO-RO) vessel. The impact velocity of the fragments was calculated based on the TNT equivalent mass corresponding to the explosion pressure. Damage and thermal-structural response analyses of the firewall were performed using Ansys LS-DYNA code. The fire resistance reduction was analyzed in terms of the temperature difference between fire-exposed and unexposed surfaces, temperature increase rate, and reference temperature arrival time. The degree of damage and the fire resistance performance of the firewalls varied significantly depending on impact loads. When naval ships and RO-RO vessels that carry various explosive substances are designed, it is reasonable to predict that the fire resistance performance will be degraded according to the explosion characteristics of the cargo.