• Structural Engineering and Mechanics
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• 제59권5호
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• pp.853-866
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• 2016

This paper examines a methodology for computing the probability of structural failure of reinforced concrete beams subjected to fire. The significant load variables considered are dead load, sustained live load and fire temperature. Resistance is expressed in terms of moment capacity with random variables taken as yield strength of steel, concrete class (or grade of concrete), beam width and depth. The flexural capacity is determined based on the design equations recommended in Indian standard IS456:2000. Simplified method named $500^{\circ}C$ isotherm method detailed in Eurocode 2 is incorporated for fire design. A transient thermal analysis is conducted using finite element software ANSYS$^{(R)}$ Release15. Reliability is evaluated from the initial state to 4h of fire exposure based on the first order reliability method (FORM). A procedure is coded in MATLAB for finding the reliability index. This procedure is validated with available literature. The effect of various parameters like effective cover, yield strength of steel, grade of concrete, distribution of reinforcement bars and aggregate type on reliability indices are studied. Parameters like effective cover of concrete, yield strength of steel has a significant effect on reliability of beams. Different failure modes like limit state of flexure and limit state of shear are checked.

• Steel and Composite Structures
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• 제38권2호
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• pp.121-139
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• 2021

Ultra-high strength concrete (UHSC) encased steel columns are receiving growing interest in high-rise buildings owing to their economic and architectural advantages. However, UHSC encased steel columns are not covered by the modern fire safety design code. A total of 14 fire tests are conducted on UHSC (120 MPa) encased steel columns under constant axial loads and exposed to ISO-834 standard fire. The effect of load ratio, slenderness, stirrup spacing, cross-section size and concrete cover to core steel on the fire resistance and failure mode of the specimens are investigated. The applicability of the tabulated method in EC4 (EN 1994-1-2-2005) and regression formula in Chinese code (DBJ/T 15-81-2011) to fire resistance of UHSC encased steel columns are checked. Generally, the test results reveal that the vertical displacement-heating time curves can be divided into two phases, i.e. thermal expansion and shortening to failure. It is found that the fire resistance of column specimens increases with the increase of the cross-section size and concrete cover to core steel, but decreases with the increase of the load ratio and slenderness. The EC4 method overestimates the fire resistance up to 186% (220 min), while the Chinese code underestimates it down to 49%. The Chinese code has a better agreement than EC4 with the test results since the former considers the effect of the load ratio, slenderness, cross section size directly in its empirical formula. To estimate the fire resistance precisely can improve the economy of structural fire design of ultra-high strength concrete encased steel columns.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2005년도 춘계학술논문발표회 논문집
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• pp.189-189
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• 2005

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1999년도 추계학술발표회 논문 초록집
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• pp.143-148
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• 1999

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2000년도 추계학술대회 논문집
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• pp.147-152
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• 2000

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2000년도 추계학술대회 논문집
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• pp.103-107
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• 2000

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2004년도 하계학술논문발표회 논문집
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• pp.217-224
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• 2004

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2004년도 하계학술논문발표회 논문집
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• pp.232-238
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• 2004

• 복합신소재구조학회 논문집
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• 제6권1호
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• pp.21-29
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• 2015

Other countries(USA, Europe) have performed the fire resistance design of buildings by the alternative performance design methods, which are based on fire engineering theories. However, in Korea, the process on the alternative fire resistance performance design has only suggested without any applications for real steel structures. Therefore, In the case of steel structures stagnant research on refractory measures face difficulties in introducing fire resistance design. In this study, first of all, Intumescent paint was analyze the thermal properties(thermal conductivity, specific heat and density). In Sequence, using the section factor by H-standard section propose of section concrete filled steel tube and hollow. finally presents a reasonable thickness Intumescent paint takes time to target performance of the proposed cross-section steel tube.

• 한국화재소방학회논문지
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• 제14권4호
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• pp.23-28
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• 2000

반도체 공장의 제연설계를 위한 성능기준 설계를 분석하였다. 사례분석을 통하여 제연 설계 시스템의 성능평가 기준을 설정하고 최적의 배연 방법을 분석하기 위한 FDS 화재모델링을 수행하였다. 제연 설계 지침이나 관련 법규 또는 표준화된 기준이 부족한 한국과 미국의 현실에서 본 연구의 성능기준 설계 방법은 반도체공장의 제연 설계를 위한 현실적인 적용과 활용이 기대된다.