• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.19-27
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• 2017

This paper is a study to improve the fire-resistance capacity of reinforced concrete (RC) members strengthened by fiber-reinforced-polymer (FRP). The fire resistance of the RC members strengthened by FRP was evaluated through high temperature exposure test. In order to improve the fire resistance of the FRP reinforcing method, a fire-proof board was attached to the reinforced FRP surface and then the high temperature exposure test was carried out to evaluate the improvement of the fire resistance performance. It was confirmed that the resistance to high temperature of NSMR could be improved somewhat compared with that of EBR from the experiment that exposed to high temperature under the load corresponding to 40% of nominal strength. When 30 mm thick fire-resistance (FR) board is attached to the FRP surface, the surface of the reinforced FRP does not reach $65^{\circ}C$, which is the glass transition temperature (GTT) of the epoxy until the external temperature reaches $480^{\circ}C$. In particular, when a high performance fire-proof mortar was first applied prior to FR board attachment, the FRP portion did not reach the epoxy glass transition temperature until the external temperature reached $600^{\circ}C$.

• Steel and Composite Structures
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• v.38 no.6
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• pp.657-670
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• 2021

This paper presents a designing method for enhancing fire resistance of steel box bridge girders (closed steel box bridge girder supporting a thin concrete slab) through taking into account such parameters namely; fire severity, type of longitudinal stiffeners (I, L, and T shaped), and number of longitudinal stiffeners. A validated 3-D finite element model, developed through the computer program ANSYS, is utilized to go over the fire response of a typical steel box bridge girder using the transient thermo-structural analysis method. Results from the numerical analysis show that fire severity and type of longitudinal stiffeners welded on bottom flange have significant influence on fire resistance of steel box bridge girders. T shaped longitudinal stiffeners applied on bottom flange can highly prevent collapse of steel box bridge girders towards the end of fire exposure. Increase of longitudinal stiffeners on bottom flange and web can slightly enhance fire resistance of steel box bridge girders. Rate of deflection-based criterion can be reliable to evaluate fire resistance of steel box bridge girders in most fire exposure cases. Thus, T shaped longitudinal stiffeners on bottom flange incorporated into bridge fire-resistance design can significantly enhance fire resistance of steel box bridge girders.

• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.272-281
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• 2013

Concrete filled tube (CFT) columns, which consist of a steel tube filled with concrete, combine the benefits of the two materials. The steel tube provides a confining pressure to the concrete, while the local buckling of steel plate can be prevented by the concrete core. CFT columns also have a high fire resistance due to the heat storage effect of concrete under fire. For this reason, it is possible to develop CFT columns without fire protection measures. CFT columns without fire protection have many advantages, including quality control, cost reduction, better space efficiency and a shorter construction period. Due to these advantages, studies on the development of CFT columns without fire protection measures have been performed. However, CFT columns lose their bearing capacity under fire because the steel tube is exposed to the outside. As a result, the structure is collapsed, causing significant damage. In this research, we made a CFT column using high strength concrete (100 MPa) and high strength steel (800 MPa). We use steel fiber and nylon fiber with concrete to provide fire resistance. We perform the fresh concrete experiment and investigate the fire resistance of the CFT column (${\Box}400{\times}400{\times}15{\times}3000mm$) under loading. To investigate the effect of steel fiber on increasing fire resistance, we compare the fire resistance time according to the steel fiber. Through the test, it was found that the CFT specimen with steel fiber had better fire resistance performance than other cases.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.199-202
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• 2008

The purpose of this study is to obtain the fundamental fire resistance performance of engineered cementitious composites(ECC) under fire temperature in order to use the fire protection material in high-strength concrete structures. The present study conducted the experiment to simulate fire temperature by employing of ECC and investigated experimentally the explosion and cracks in heated surface of these ECC. In the experimental studies, 3 HSC specimens are being exposed to fire, in order to examine the influence of various parameters(such as depth of layer=20, 30, 40mm; construction method=lining type) on the fire performance of HSC structures. Employed temperature curve were ISO 834 criterion(3hr), which are severe in various criterion of fire temperature in building structures. The numerical regressive analysis and proposed equation to calculate ambient temperature distribution is carried out and verified against the experimental data. By the use of proposed equation, the HSC members subjected to fire loads were designed and discussed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.143-152
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• 2006

High performance concrete(HPC) has been widely used in high-rise building. The HPC has several benefits including high strength, high fluidity and high durability. However, spalling is susceptible to occur in HPC and HPC also tends to be deteriorated in the side of fire resistance performance at fire. This paper investigated the spalling prevention of high performance RC column. Control concrete showed severe failure and a case of concrete with fire enduring spraying material exhibited more severe spalling failure than even control concrete. In addition, concrete with fire enduring paint reported the most favorable spalling resistance effect for preventing spall, compared with other concrete covered with finishing materials, such as fire enduring spraying material, gypsum board, marble board and fire enduring PC board. Meanwhile, concrete adding 0.1% of PP fiber demonstrated spalling resistance performance after 3hours load bearing test.

• Fire Science and Engineering
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• v.30 no.5
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• pp.82-86
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• 2016

The fire resistance of a statistically indeterminate beam made of fire resistant steel was analyzed using the mechanical and thermal databases and compared with that of an indeterminate beam constructed of ordinary structural steel to not only determine the fire resistance performance of a statistically indeterminate beam itself, but also to determine if it is stable to test the fire resistance performance with a determinate beam built with ordinary structural steel instead of an indeterminate beam made from fire resistant steels. The results showed that the fire resistance of an indeterminate beam consisting of fire resistant steels is better than that of a determinate beam made of SS 400 and if the length of the beam built with FR 490 is longer, the displacement of the beam is higher. In addition, the fire test with a determinate beam made of SS 400 is was more conservative than that of an indeterminate beam made of FR 490 in the range of the same length. Therefore, another measure should be considered if beams built with FR 490 are longer than thos of SS 400.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.229-234
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• 2008

Performance based fire engineering design is being adopted around the world as a rationed means of providing efficient and effective fire safety in Building. This development is being supported by the adoption of performance based codes which specify the objective and minimum performance requirements for fire safety traditional design for fire safety which is still practiced in many countries, relies on "prescriptive" codes which specify how a building is to be built, which no statement of objective and little or no opportunity to offer more rational alterative design. It is the aim of this study to investigate and analyze the research direction of structural fire resistance design of steel structures for recommendation of PBD in Korea.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05b
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• pp.43-47
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• 2010

The use of high-strength concrete has increased for its excellent structural stability as buildings become higher and bigger than ever before in Korea and overseas recently. The functional requirement of building materials has also been bolstered so for the high -performance, high-quality construction materials to be used more extensively. However, the internal structure of the high-strength concrete is very dense so spalling can be caused during fire. The spalling in turn can cause critical structural damages followed by the fatal consequences, demolition of the building. Therefore, ensuring fire safety for high-rise buildings is assumed to be urgent. Alumino-silicate fire resistant board producing technology has been developed in situations that new materials with excellent fire resistance and easy installation has been sought. The alumino-silicate fire resistant board turned out to exhibit not only fire resistance and excellent physical and dynamical characteristics but also excellent onsite applicability and easy process and transportation after completing Mock-up test. Its excellence as a high-performance building materials was proven.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.78-85
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• 2010

When the fire occur, concrete filled steel tube(CFT) columns expected to form a much distinction in a fire resistance performance according to a kind of fire protection because the steel surface is directly exposed to high temperature. In this study, an experiment by three factors which were kind of fire protection, thickness of protection and time was performed to get the characteristics of temperature distribution types of CFT column with fire protection. As the result of this study, on a basis of heating temperature, spray protection was the most superior in a fire resistance performance, fireproof paint was next, and without fire protection was most inferior. In a heating time-location relationship, the temperature increased slowly on the surface of the concrete, but the temperature increased sharply on the surface of the steel.

• Journal of the Korea Institute of Building Construction
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• v.22 no.3
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• pp.239-249
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• 2022

Fire resistance performance and performance design of fire doors are becoming more important to prevent the spread of fire and support the rapid evacuation of apartment buildings. In this study, a database using 182 evacuation spaces and 308 common areas that passed the fire performance test was established, and fire door performance influencing factors were derived through an analysis of the structure(12 elements) of the fire door. As a result, the effects of fire-resisting filler density, adhesive, and foam gasket were confirmed for evacuation space, and the effects of fire-resisting filler, adhesive, and fire fins were confirmed for common areas. In the fire door fire resistance test, flames and cracks were analyzed as the most frequent failure factors.