• Earthquakes and Structures
• /
• v.10 no.4
• /
• pp.867-891
• /
• 2016

This paper addresses numerically the behavior of steel structures under Fire-after-Earthquake (FAE) loading. The study is focused on a four-storey library building and takes into account the damage that is induced in structural members due to earthquake. The basic objective is the assessment of both the fire-behavior and the fire-resistance of the structure in the case where the structure is damaged due to earthquake. The combined FAE scenarios involve two different stages: during the first stage, the structure is subjected to the ground motion record, while in the second stage the fire occurs. Different time-acceleration records are examined, each scaled to multiple levels of the Peak Ground Acceleration (PGA) in order to represent more severe earthquakes with lower probability of occurrence. In order to study in a systematic manner the behavior of the structure for the various FAE scenarios, a two-dimensional beam finite element model is developed, using the non-linear finite element analysis code MSC-MARC. The fire resistance of the structure is determined using rotational limits based on the ductility of structural members that are subjected to fire. These limits are temperature dependent and take into account the level of the structural damage at the end of the earthquake and the effect of geometric initial imperfections of structural members.

• Steel and Composite Structures
• /
• v.14 no.3
• /
• pp.295-312
• /
• 2013

In this paper, a simplified approach based on critical temperature for fire resistance design of steel-concrete composite beams is proposed. The method for determining the critical temperature and fire protection of the composite beams is developed on the basis of load-bearing limit state method employed in current Chinese Technical Code for Fire safety of Steel Structure in Buildings. Parameters affecting the critical temperature of the composite beams are analysed. The results show that at a definite load level, section shape of steel beams, material properties, effective width of concrete slab and concrete property model have little influence on the critical temperature of composite beams. However, the fire duration and depth of concrete slab have significant influence on the critical temperature. The critical temperatures for commonly used composite beams, at various depth of concrete and fire duration, are given to provide a reference for engineers. The validity of the practical approach for predicting the critical temperature of the composite beams is conducted by comparing the prediction of a composite beam with the results from some fire design codes and full scale fire resistance tests on the composite beam.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.961-964
• /
• 2008

Fire safety is one of the important factors to be examined when applying ECC to actual concrete structures. The purpose of this study is to confirm whether the fire resistance of ECC satisfies the fire resistant requirements in order to use the fire protection material in concrete structures. Employed temperature curve are HC and RABT criterion, which are severe in various criterion of fire temperature in concrete structures. The test results show that ECC did not undergo any deterioration of fire resistance nor cause explosive spalling, which had been anticipated due to the presence of organic fibers. With comparison of current concrete and fire-resistance materials, the experimental results of ECC shows the better fire resistance performance than the other.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.6
• /
• pp.703-714
• /
• 2007

The aim of this research is to evaluate the fire resistance of concrete-filled steel square tube columns (square CFT columns) under constant axial loads by numerical analysis. The authors examined the experimental results on the fire resistance of concrete-filled steel square tube columns without fire protection. As the materials of CFT columns, steel of SPSR 400 grade and concrete of 27.5MPa and 37.8MPa strengths were used. The significant parameters were determined, such as load ratio, cross-sectional dimensions, and concrete strength. Detailed analytical simulations of fire resistance and axial deformation showed good agreement with the experimental observations. Therefore, this numerical analysis exhibited a reasonable estimation of fire resistance of the square CFT column. Results of the numerical parametric studies showed that the fire resistance of the CFT columns increased with the decrease of the concrete strength and the increase of the cross-sectional dimensions about the constant axial load ratio ($N/N_c$).

• Journal of the Korea Institute of Building Construction
• /
• v.10 no.5
• /
• pp.129-135
• /
• 2010

The purpose of this research is to secure fundamental data on the application of fibre as a fire resistance method for more than 60 MPa high-strength concrete through an examination of mechanical properties and fire resistance performance. The results are as follows: 1) When there are less than 0.5~1.0kg/$m^3$ contents of PP and NY fibre for 60MPa and less high strength concrete, 1.0kg/$m^3$ contents of PP and NY fibre for less than 80MPa high strength concrete and 1.5kg/$m^3$ contents of NY fibre for more than 80MPa high strength concrete, the effect of fibre contents on workability and strength development is not significant. 2) Based on the result of a 3-hour fire resistance test for mock-up column, it is necessary to secure 50 mm of covering depth for the regulation of fire resistance performance of high strength concrete to the standards of The Ministry of Land, Transport and Maritime Affairs. 3) It is necessary to secure more than 400mm of column size for stable fire resistance performance.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.18 no.3
• /
• pp.28-39
• /
• 2014

This paper reviews past literatures relevant to fire-resistance properties of high strength concrete and investigates spalling mechanism of high strength concrete in fire. First, literatures were reviewed on spalling occurrence and fire-resistance methods. Second, a chemical change of concrete components in an elevated temperature was presented. Finally, the mechanism of the spalling occurrence and spalling resistance were examined in terms of hybrid fiber content. The focus of the experimental study as part of this research is to investigate the effects of fire on the variation of thermal properties of high strength concrete, which tends to be used in super tall buildings. This experimental study was devised to investigate the fire-resistance performance of high strength concrete containing hybrid fibers. A total of 48 test specimens were exposed to high temperature ranging from $100^{\circ}C$ to $700^{\circ}C$, including room temperature (${\sim}20^{\circ}C$). Test results provide valuable information regarding fire-resistance properties of strength concrete with 100 MPa or greater.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.749-752
• /
• 2005

Normally, the degradation of concrete member exposed to fire is largely dependent on the fire scale and fire condition. With all ensuring the fire resistance structure as a method of setting the required cover thickness to fire, the RC is significantly affected from the standpoint of its structural stability that the compressive strength and elastic modulus is reduced by fire. Thus, this study is concerned with experimentally investigating fire resistance of high strength-light weight concrete. From the test result, high strength-light weight concrete is happened explosive spalling. The decrease of cross section caused by explosive spalling made sharp increasing gradient of inner temperature.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.11a
• /
• pp.235-236
• /
• 2022

Electric vehicle fires in underground parking lots are very dangerous, but it is judged that the current related laws and regulations do not change, which will cause problems. As a result of the analysis for the purpose of providing an electric vehicle in an underground parking lot, fire-resistance coating is essential as it can cause an explosion in the building members made of high-strength concrete when an electric vehicle fire occurs in an underground parking lot. Since a fire occurs, it is necessary to prevent electric vehicles from parking adjacent to each other.

• International Journal of High-Rise Buildings
• /
• v.12 no.3
• /
• pp.235-239
• /
• 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.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.149-150
• /
• 2015

Structural beam plays a key role to carry the applied load on the floors. And then the beam have to sustain the applied load and its load-bearing capacity in fire situation. In this study to know the fire resistance performance of long span beam made of a submarine structural steels, an engineering method is used using mechanical and thermal properties of structural steel at high temperature.