• Title, Summary, Keyword: fire resistance

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Evaluation of the Fire Resistance Performance of Interior Anchor Type CFT Columns through Loaded Heating Test

  • Kim, Sunhee;Yom, Kyongsoo;Choi, Sungmo
    • International Journal of High-Rise Buildings
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    • v.2 no.1
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    • pp.39-48
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    • 2013
  • The fire resistance performance of generic CFT columns has been verified through various tests and analyses and the columns are widely used for fire resistance designs abroad. In this study, 3 groups of specimens (Non-fire protection, reinforcement with steel fiber and fire resistance paint) are suggested in order to evaluate the fire resistance performance of interior anchor type concrete-filled steel tubular columns having efficient cross-sections through loaded heating tests. Axial deformation-time relationship and in-plane temperatures are compared to evaluate the fire resistance performance of the specimens associated with variables. Suggested from the fact that the interior anchors exposed to fire exert influence on fire resistance performance due to thermal expansion, the reinforcements using steel fiber and fire resistance paint are verified to mitigate contraction and improve fire resistance performance. The result obtained from the tests of interior anchor type concrete-filled tubular columns is expected to be used for effective fire resistance design in association with previously conducted studies.

A Study on the fire-resistance of concrete-filled steel square tube columns without fire protection under constant central axial loads

  • Park, Su-Hee;Choi, Sung-Mo;Chung, Kyung-Soo
    • Steel and Composite Structures
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    • v.8 no.6
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    • pp.491-510
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    • 2008
  • This paper presents a plan and guidelines that were drawn for Korean based research carried out on the fire-resistance of CFT columns. This research was carried out by reviewing the Korean regulations related to the fire-resistance of CFT columns and examining studies which had been made in Korea as well as overseas. The first phase of the study plan was to compare the fire-resistance of square CFT columns without fire protection (obtained through fire-resistance tests and numerical analyses) with estimated values (obtained through fire-resistance design formulas proposed in Korea and overseas). This comparison provided conclusions as outlined below. Fire-resistance tests conducted in this study proved that, when the actual design load is taken into consideration, square CFT columns without fire protection are able to resist a fire for more than one hour. A comparison was made of test and analysis results with the fire-resistance time based on the AIJ code, the AISC design formula and the estimation formula suggested for Korea. The results of this comparison showed that the test and analysis results for specimens SAH1, SAH2-1, SAH2-2 and SAH3 were almost identical with the AIJ code, the AISC design formula and estimation formula. For specimens SAH4 and SAH5, the estimation formula was more conservative than the AIJ code and the AISC design formula. It was necessary to identify the factors that have an influence on the fire-resistance of CFT columns without fire protection and to draw fire-resistance design formulas for these columns. To achieve this, it is proposed that numerical analyses and tests be conducted in order to evaluate the fire-resistance of circular CFT columns, the influence of eccentricity existing as an additional factor and the influence of the slenderness ratio of the columns. It is also suggested that the overall behavior of CFT structures without fire protection within a fire be evaluated through analysis simulation.

A Study on the Method of Resistance Analysis of Water Stream During Fire Supperession (화재진압 시 발생하는 주수 기둥의 저항분석 방법 연구)

  • Jung, Byeong-Sun;Kim, Eung-Sik;Park, Jong-Yeol
    • Journal of the Korean Society of Safety
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    • v.33 no.6
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    • pp.22-27
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    • 2018
  • Fire fighters are exposed to the risk of many accidents during fire suppression, especially near the high voltage circuit. In order to prevent and analyze the electric shock accidents, measurement of water resistance is crucial. However, this has been one of the overlooked research areas and it has been very difficult to measure the mixed up resistance components separately. In this paper, we measured a total resistance of apparatus and regarded it as a serial resistance of contact resistance and length dependant resistance. Measuring the resistance by varying the length of water stream, the variable resistance and fixed contact resistance appear, which are used to calculate the both components of resistances. In addition, the resistance of fire hose can be calculated from the parallel circuit which is formed by grounding the fire hose with the resistance of water stream. Results show that we can successfully measure the resistance per unit length of water stream and fire hose, thereby proving that this method is a facile way to measure water and fire hose resistance. However, many experiments are still required to obtain the precise contact resistance of ground under various condition and the resistance between the human body and fire hose.

A Study on the Application of Gypsum Board through the Application of Fire Resistance Ceiling Structure (내화천장구조 적용을 통한 석고보드 활용 확대에 관한 연구)

  • Choi, Dong-ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.217-218
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    • 2019
  • Fire resistance ceiling system is the structure of which the ceiling installed under the slave of the structure has the fire resistance performance. Because of having the fire resistance performance, fire resistive coatings on steel beams can be reduced and large span structures can be constructed. So, it have advantages of convenience for construction, shorten for construction time and cost reducing. In foreign country, it is general that one system consisting of slave and ceiling is constructed as a fire resistance system, in these cases, gypsum boards are mostly used as ceiling materials. The purpose of this study was to explain the possibility of expanding the use of gypsum boards by securing fire resistance performance of these ceilings.

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An Experimental Study on the Fire Resistance Performance of Intumescent Coating System with Time Elapse (경년변화에 따른 내화도료의 내화성능에 관한 실험적 연구)

  • Kim, Dae-Hoi;Sung, Si-Chang;Choi, Dong-Ho;Park, Soo-Young;Lee, Sea-Hyun;Lee, Jong-Chan
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • pp.61-64
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    • 2008
  • Applying fire resistive coating to steel members is one of the general methods to secure fire resistance performance of steel members. And intumescent coating system is currently one of methods giving fire resistance to steel members. Intumescent coating system for fire resistance, however, has undesirable weaknesses that fire resistance performance of steel members is being deteriorated due to cracks and falling-offs of the coverings as time goes after completion of the coverings to the members. This study is designed to understand changes in fire resistance performance of intumescent coating system through follow-up tests on temperature of unexposed surface for the domestic intumescent coating system.

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Evaluation of Fire Resistance Using Mechanical Properties at High Temperature for Steel Column Made of Rolled Steels (SS 400) (구조용 압연강(SS 400)의 고온 기계적 특성을 이용한 기둥부재의 내화성능 평가)

  • Kwon, In-Kyu;Shin, Soon-Gi
    • Korean Journal of Metals and Materials
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    • v.49 no.9
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    • pp.671-677
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    • 2011
  • Steel columns used in steel buildings are inclined to lose their strength when exposed to severe fire conditions, so fire resistance is required in most countries to protect against loss of life and building collapses. In Korea, the fire resistance of columns can be obtained by the fire test defined in KS F 2257-1, 7. The fire resistance of a steel column should be evaluated in terms of the column's conditions, such as various section types (H-section, hollow-section), the column's length and boundary conditions, and whether it is fixed or hinged. However, fire testing of steel columns is usually conducted on one standard-sized H-section over 3,000 mm, and the result is used as the column's fire resistance. This is not a reasonable way to ensure that a building can withstand fire conditions. In this study, to evaluate the possibility of calculating the fire resistance of steel columns with material properties of high tensile strength of SS 400, both load-bearing fire tests and calculation of steel temperatures were carried out. The results of temperature calculation were very similar to those obtained by fire test.

Designing method for fire safety of steel box bridge girders

  • Li, Xuyang;Zhang, Gang;Kodur, Venkatesh;He, Shuanhai;Huang, Qiao
    • 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.

Behavior of composite box bridge girders under localized fire exposure conditions

  • Zhang, Gang;Kodur, Venkatesh;Yao, Weifa;Huang, Qiao
    • Structural Engineering and Mechanics
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    • v.69 no.2
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    • pp.193-204
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    • 2019
  • This paper presents results from experimental and numerical studies on the response of steel-concrete composite box bridge girders under certain localized fire exposure conditions. Two composite box bridge girders, a simply supported girder and a continuous girder respectively, were tested under simultaneous loading and fire exposure. The simply supported girder was exposed to fire over 40% of its span length in the middle zone, and the two-span continuous girder was exposed to fire over 38% of its length of the first span and full length of the second span. A measurement method based on comparative rate of deflection was provided to predict the failure time in the hogging moment zone of continuous composite box bridge girders under certain localized fire exposure condition. Parameters including transverse and longitudinal stiffeners and fire scenarios were introduced to investigate fire resistance of the composite box bridge girders. Test results show that failure of the simply supported girder is governed by the deflection limit state, whereas failure of the continuous girder occurs through bending buckling of the web and bottom slab in the hogging moment zone. Deflection based criterion may not be reliable in evaluating failure of continuous composite box bridge girder under certain fire exposure condition. The fire resistance (failure time) of the continuous girder is higher than that of the simply supported girder. Data from fire tests is successfully utilized to validate a finite element based numerical model for further investigating the response of composite box bridge girders exposed to localized fire. Results from numerical analysis show that fire resistance of composite box bridge girders can be highly influenced by the spacing of longitudinal stiffeners and fire severity. The continuous composite box bridge girder with closer longitudinal stiffeners has better fire resistance than the simply composite box bridge girder. It is concluded that the fire resistance of continuous composite box bridge girders can be significantly enhanced by preventing the hogging moment zone from exposure to fire. Longitudinal stiffeners with closer spacing can enhance fire resistance of composite box bridge girders. The increase of transverse stiffeners has no significant effect on fire resistance of composite box bridge girders.

An Experimental Study on Fire Resistance Performance Test of Non-loadbearing Ceiling Systems (비내력 천장구조 내화성능평가에 대한 실험적 연구)

  • Choi, Dong-Ho;Kim, Dae-Hoi;Park, Soo-Young
    • Fire Science and Engineering
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    • v.25 no.4
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    • pp.22-27
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    • 2011
  • Fire resistance ceiling system is the structure of which the ceiling installed under the slave of the structure has the fire resistance performance. Because of having the fire resistance performance, fire resistive coatings on steel beams can be reduced and large span structures can be constructed. So, it have advantages of convenience for construction, shorten for construction time and cost reducing. In foreign country, it is general that one system consisting of slave and ceiling is constructed as a fire resistance system. But in Korea, there are no fire resistance ceiling systems thus economical efficiency due to being high-rise and light-weight of structures is not secured. Therefore research and development of nominal fire resistance ceiling systems is necessary. On this study, fire resistances of standard non-loadbearing ceiling systems were assessed and basic informations for developing the fire resistance non-loadbearing ceiling systems were presented.

A Study on the Fire Resistance Design of Buildings Considering the Fire Load Energy Density (화재하중밀도를 고려한 건축물의 내화설계법에 관한 연구)

  • 이평강;이용재;최인창;김회서
    • Fire Science and Engineering
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    • v.17 no.2
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    • pp.10-16
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    • 2003
  • The main purpose of this study is to raise the point at issue and to propose reform direction about the current performance criteria of fire resistance through the examination of the fire resistance required for each use of compartment by using performance-based fire safety design method. To examine the performance criteria of fire resistance, this study compared the equivalent time of fire exposure which was calculated by using time-equivalent formulae with the required fire resistance time determined by existing prescriptive code, and surveyed factors such as the fire load energy density, ventilation factor, fire compartment materials and fire compartment geometry in order to calculate the equivalent time of fire exposure.