• Journal of Korean Society of Steel Construction
• /
• v.27 no.4
• /
• pp.387-397
• /
• 2015

The domestic fire resistance performance test is conducted as a prescriptive design method such as quality test. In quality test there are 2 methods, unloaded fire resistance test and fire resistance test under load. In realistic, these tests, however, have problems with expense, time and diversity of structure. This study reviewed fire resistance performance of H-beam flexural member by thermal stress analysis using finite element ABAQUS program. This research is for the performance-based design reviewing applicability of domestic standard. As a result of this study, limit temperatures per each load ratio provied for proper performance of fire resistancy.

• Steel and Composite Structures
• /
• v.38 no.2
• /
• pp.121-139
• /
• 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.

• Structural Engineering and Mechanics
• /
• v.7 no.2
• /
• pp.127-145
• /
• 1999

This paper deals with the development of an approach for evaluating the squash load and rigidity of unprotected concrete filled steel columns at elevated temperatures. The current approach of evaluating these properties is reviewed. It is shown that with a non-uniform temperature distribution, over the composite cross-section, the calculations for the squash load and rigidity are tedious in the current method. A simplified approach is proposed to evaluate the temperature distribution, squash load, and rigidity of composite columns. This approach is based on the model in Eurocode 4 and can conveniently be used to calculate the resistance to axial compression of a concrete filled steel column for any fire resistance time. The accuracy of the proposed approach is assessed by comparing the predicted strengths against the results of fire tests on concrete filled circular and square steel columns. The applicability of the proposed approach to a design situation is illustrated through a numerical example.

• Journal of Korean Association for Spatial Structures
• /
• v.16 no.4
• /
• pp.53-58
• /
• 2016

SLIM AU(A plus U-shaped) composite beam was developed for reducing the story height in the residential buildings, and saving the cosrtuction cost of floor structures. Structural performance and economic feasibility of the composite beam have been sufficiently approved through the structural experiments and the analytical studies. However, the verification for fire safety is necessary for the practical application of the composite beam. The fire resistance tests with and without loading were performed for the fire safety verification, and the test results were summarized in this paper.

• Fire Science and Engineering
• /
• v.32 no.1
• /
• pp.40-45
• /
• 2018

It is considered that vermiculite as an inorganic material is highly effective when it is used as a building finishing material because it is eco-friendly. Vermiculite has excellent properties such as fire resistance, heat insulation, sound absorption as well as prevention of condensation, deodorization and aesthetics. In this study, we developed a finishing board with vermiculite as its main material and mixed with mineral loose wool (VB-L) or mineral powder (VB-P), and conducted fireproof test and insulation test. In addition, fire resistance tests were carried out by applying the two developed vermiculite boards as finishing materials for the standard wall details of light frame wood structures (KS F 1611-1). As a result of the fire resistance test, the VB-L specimen showed better fire resistance than the VB-P specimen. Both vermiculite boards showed sufficient fire resistance performance of 2 hours for a thickness of 30 mm.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.05a
• /
• pp.21-22
• /
• 2015

The CFT(Concrete Filled Tube) system has been developed to behave well in a structural performance such as stiffness, stress, ductility, fire resistance that is derived from its mechanical advantages of composite structure. There were number of studies about unprotected CFT columns for improving their fire resistance through reinforcing bars or plates being placed inside the steel tube. It was also known that reinforcing plates of flat type need stiffeners in a certain distance to avoid their buckling failure so it cost as much as their using consequentially. This paper is planned to test the work of beam elements attached inner side of CFT depending on its shape. More discussions on beam's design could be followed after some fire tests accordingly conducted within this project.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.4
• /
• pp.15-22
• /
• 2019

The use of modular buildings is increasing because of various advantages of modular buildings. But there are limits to apply modular buildings to medium-rise buildings because the building law provides only the specification criteria of the modular building with respect to the 1 hour fire resistance performance. This study was conducted to investigate 2 hours fire resistance performance of load bearing walls with steel studs in modular buildings by KS F 2257-1 and KS F 2257-4. After full scale tests, load bearing walls ensuring two hours fire resistance performance consist of at least 2 layers of fire resistance plaster boards of 19mm thickness or 3 layer of fire resistance plaster boards of thickness.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.2
• /
• pp.1-8
• /
• 2011

Concrete filled steel tubes(CFST) is considered as a column having better structural stability and better performance of fire resistance than that made with H-section and hollow section in itself. To get the fire resistance of the CFST, two kinds of concrete strength were used, 21 MPa, 40 MPa and 4 sorts of the applied loads were calculated and used to the specimens such as 3.5 m long, round and rectangular section. After various fire tests under 4 sorts of load ratios, the fire resistance of the CFST is not possible to get over 1 hour because of the rapid decrease of concrete strength. The below 50% of the applied load is recommended to obtain over 1 hour fire resistance of the CFST.

• Journal of the Society of Disaster Information
• /
• v.19 no.2
• /
• pp.262-269
• /
• 2023

Purpose: In this study,fire-resistance test were executed to evaluate the effectiveness of the fireproof panel attached to the PSC slab in tunnel. Method: For the fire resistance test, the RWS curve was applied and the furnace of the KICT was used. Result: As a result of the experiment, the maximum temperature measured on the concrete surface of the PSC slab with the fireproof panel was 321.8℃, which was lower than the damage limit temperature of 380℃ for concrete. Also, at the t=25mm, the maximum temperature was 35.2℃, which was lower than the damage temperature of steel, 250℃. The use of precast fire resistance panel(t=30mm) improves fire resistance of PSC structures. Conclusion: As a result of the test, a reinforcement method for attached a fireproof panel in case of fire in a tunnel or an underground roadway is provided to protect a structure from fire. In the future, it is necessary to perform the static performance test of the slab to which the fireproof panel is attached, and to confirm the adhesion performance of the fireproof panel by performing the pull-off test and the fatigue test.

• Steel and Composite Structures
• /
• v.3 no.2
• /
• pp.75-95
• /
• 2003

A numerical model is presented to simulate the mechanical behaviour of composite steel and concrete columns taking into account the interaction between the hollow steel section and the concrete core. The model, based on displacement finite element methods with an Updated Lagrangian formulation, allows for geometrical and material non linearities combined with heating over all or a part of the section and column length. Comparisons of numerical calculations made using the model with 33 fire resistance tests show that the model is able to predict the fire resistance, expressed in minutes of fire exposure, of composite columns with a good accuracy.