• Fire Science and Engineering
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• v.27 no.3
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• pp.72-79
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• 2013

Recently, building constructions have been developed toward high-rise, long span, and multi-complexed using the high strength materials, optimized section. But the structural behavior of steel structural members built with a high strength steel at fire condition is not clarified because of lacking of information of related references such as mechanical and thermal properties at high temperature situation. In this paper, to evaluate the structural stability of member or frame of steel framed building at fire situation through the engineering method, the mechanical and thermal experimental coupon tests have conducted at various high temperatures and the comparison to those of ordinary strength steels were done.

• Fire Science and Engineering
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• v.12 no.4
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• pp.31-40
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• 1998

Very often, whether accidentally or intentionally set fire, according as building are elevated, varied or complicated day by day. It is of primary importance that we have a treatment of fire damaged structure. In general, strength and elasticity modulus of heated concrete are reduced. Product background of cement, sand and coarse aggregate differ from country to country, so that thermal behaviour of concrete make a difference in high temperature. To cope with demand, this paper is a study on relation to microstructure and strength reduction. In consequence of experiments, concrete exposed to high temperature are estimating the reduction of mechanical properties in comparison with microstructure characteristics which are abtained from the SEM/EDX, XRD and DSC-TG analysis of heated specimens under various temperature.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.100-106
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• 2014

High strength concrete has a structural advantage as well as superior usability and durability, so that its application in building is being steadily augmented. However, in the high temperature like in a fire, the high strength concrete has extreme danger named explosive spalling. It is known that the major cause of explosive spalling is water vapour pressure inside concrete. General solution for preventing concrete from spalling include applying fire protection coats to concrete in order to control the rising temperature of members in case of fire. The purpose of this study is to investigate the high temperature properties of fireproof mortar using organic fiber and various types of fine aggregate for fire protection covering material. The results showed that addition of perlite and polypropylene fiber to mortar modifies its pore structure and reduces its density. This causes the internal temperature to rise. As a results, it is found that a new fireproof mortar can be used in the fire protection covering material in high strength concrete.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.374-381
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• 2015

This study is investigating the fire resistant finishing materials composed of fly ash and glass forming light weight aggregate has the high temperature thermal stability. High temperatures such as a fire, cementitious materials beget dehydration and micro crack of cement matrix. From the test result, developed fire resistant finishing materials showed good stability in high temperatures. These high temperature stability is caused by the ceramic binding and low thermal conductivity of glass forming light weight aggregate. Also, alkali activation reaction of fly ash and meta kaolin not showing the decomposition of calcium hydrates. Thus, this result indicates that it is possible to fire resistant finishing light weight mortars.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.469-472
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• 2005

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. Normally, the degradation of concrete member exposed to fire is largely dependent on the fire scale and fire condition. There is therefore a need to precisely predict the deterioration and fire damage of the exposed member. Thus, this work estimated the temperature distribution inside a member taking into consideration of the thermal properties by means of finite element method(FEM). The estimation results in a little higher prediction value than the experimental value in surface layer and is almost coincident with the experiment as the heating depth increase. From this work it can be known that the simulation application of FEM using the thermal properties of concrete member in high temperature gives rise to the confident prediction in the prediction of temperature distribution.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.81-82
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• 2018

The structure of the RC structure is actively reinforcing the structure of the building which has suffered from aging, artificial and natural damage of the building. Among various reinforcement methods, epoxy adhesive is used to attach FRP in FRP reinforcement method which is reinforcing by attaching FRP to the structural part. At this time, the epoxy adhesive having a low critical temperature has a sudden adhesive failure upon exposure to heat, and thus, the development of an inorganic fireproof adhesive having a high critical temperature has progressed. Therefore, in this study, the compositional change of inorganic fire - resistant adhesive exposed to high temperature heat was analyzed by XRD.

• Steel and Composite Structures
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• v.27 no.2
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• pp.243-253
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• 2018

In recent years, concrete-filled box or tubular columns have been commonly used in high-rise buildings. However, a number of fire test results show that there are significant differences between high strength concrete (HSC) and normal strength concrete (NSC) after being subjected to high temperatures. Therefore, this paper presents an investigation on the fire resistance of HSC filled steel tubular columns (CFTCs) under combined temperature and loading. Two groups of full-size specimens were fabricated to consider the effect of type of concrete infilling (plain and reinforced) and the load level on the fire resistance of CFTCs. Prior to fire test, a constant compressive load (i.e., load level for fire design) was applied to the column specimens. Thermal load was then applied on the column specimens in form of ISO 834 standard fire curve in a large-scale laboratory furnace until the set experiment termination condition was reached. The results demonstrate that the higher the axial load level, the worse the fire resistance. Moreover, in the bar-reinforced concrete-filled steel tubular columns, the presence of rebars not only decreased the spread of cracks and the sudden loss of strength, but also contributed to the load-carrying capacity of the concrete core.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.2
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• pp.133-140
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• 2011

High strength concrete used for large structures is vulnerable to fire due to explosive spalling when it is heated. Recently, various research is conducted to enhance the fire-resistance of the high strength concrete by reducing the explosive spalling at the elevated temperature. In this study, a heat transfer analysis model is proposed for a fiber-embedded fire-resistant high strength concrete. The material model of the fire-resistant high strength concrete is selected from the calibrated material model of a high strength concrete incorporating thermal properties of fibers and physical behavior of internal concrete at the elevated temperature. By comparing the simulated results using the calibrated model with the experimental results, the heat transfer model of the fiber-embedded fire-resistant high strength concrete is proposed.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.23-29
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• 2023

This study analyzed the fire status of a rubber product manufacturing factory based on 19 years of fire data. Through the analysis of the current state of fire, electrical fires accounted for 58.19%, and among electrical fires, motor fires were the highest at 26.21%. For the motor fire occurrence process, the curing process accounted for the highest rate of 51.9%. Therefore, the installation environment was investigated for the motor in the curing process, and it was confirmed that the motor's maximum ambient temperature exceeded 40℃. In particular, in the case of the motor for curing operation, the motor was installed in a separate motor room, so the average indoor temperature was 48.10℃ and the motor frame's maximum temperature was 72.80℃. In this study, the risk of motor fire was confirmed through a field survey, and a safety management plan was derived by finding a process with high fire risk and conducting an experiment on the motor's installation environment and electrical characteristics in that process.