• Fire Science and Engineering
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• v.23 no.6
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• pp.126-134
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• 2009

In an attempt to control the spalling in high strength concrete, spalling reducer was mixed to identify the effect and thermal characteristics of concrete beam member at high temperature. The member was manufactured in such as way of adding 40~60MPa of high strength concrete into spalling reducer, and then fire resistance performance were monitored under the ISO standard fire load condition in accordance with KS F 2257. As a result of test, fore rate performance of 40MPa beam without spalling reducer was 180minutes, 50MPa was 174minutes and 60MPa was 152minutes, indicating that 50MPa and 60MPa beam appeared 6~28minutes short to become a 3-hour rate. However, 50 and 60MPa beam mixed with spalling reducer appeared to have satisfied the requirements for 180minutes. A spalling was occurred in surface of 50 and 60MPa beam mixed without spalling reducer, while no spalling or surface failure was occurred with 50 and 60MPa beam mixed with spalling reducer. Thus polypropylene fiber mixed with the concrete proved to be effective, but viewing that the surface of 60MPa was peeled off partially, the steel fiber mixed appeared not to be effective for the beam more than 60MPa.

• Journal of ILASS-Korea
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• v.13 no.3
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• pp.156-161
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• 2008

The present article reports a numerical study on the fire characteristic change by water-mist in under-ventilated compartments. The natural gas and heptane pool fires are used as fire sources, which are located in the bottom center of the 2/5 reduced-scaled model of the ISO 9705 standard room. The fire modeling using the FDS (Fire Dynamics Simulator) is validated by comparison with previously published experimental results. For temperature and combustion gas concentrations at two positions located in the upper layer of compartment, the predicted results with and without water-mist are compared each other. The results show that under the water-mist operation, the predicted temperature and carbon monoxide concentration reduce as $300{\sim}400^{\circ}C$ and about 20%, respectively, compared to those without water-mist.

• Fire Science and Engineering
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• v.32 no.2
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• pp.1-6
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• 2018

The combustion characteristics of cypress wood coated with boric acid (BA) and ammonium pentaborate (APB) were examined using a cone calorimeter according to the ISO 5660-1 standard. As a result, the combined specimens of boric acid and ammonium pentaborate (BA/APB) led to an improved fire performance index due to their synergistic effect. In addition, the total heat release values of the specimen coated with the boron compounds were 6.1~14.1% lower than that of the base specimen. The total smoke release rate (TSR) of the specimens coated with the boron compound decreased throughout the combustion process, except for BA/APB. The maximum concentration of carbon monoxide was reduced by 15.8~25.5%. In general, wood treated with flame retardants has a lower fire hazard.

• Journal of Korean Society of Steel Construction
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• v.19 no.4
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• pp.425-434
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• 2007

The SC (steel-concrete) composite column was developed to take advantage of the relative economy of using concrete as opposed to steel in carrying large compressive forces. As the SC composite column is pre-fabricated, its use can minimize laborand can speed up the erection of a steel building. In this study, an experiment was conducted to analyze the influence of several parameters, such as the load ratio, the concrete ratio of an area, and its performance with or without fire protection, on the performance of the SC composite column. This paper proposes that the calculation of the strength reduction ratios of columns be done by increasing the temperature. Theoretical equations were used to evaluate the effectiveness of the fire resistance of the SC composite column, and the results of the test and analysis were compared. The fire resistance of the SC composite column was increased by decreasing its load ratio, but the concrete ratio of an area has minimal influence on the fire resistance of the SC composite column.

• Fire Science and Engineering
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• v.24 no.5
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• pp.128-135
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• 2010

In this study, a mixture fraction analysis was performed to investigate the characteristics of chemical species production in compartment fires burning hydrocarbon fuels such as methane, heptane, and toluene. A series of fire experiments was conducted in the ISO 9705 standard room, and gas species concentration and soot fraction were measured at two locations in the upper layer of the compartment. The mass fractions of measured chemical species, such as unburned hydrocarbons (UHC), carbon monoxide (CO), carbon dioxide ($CO_2$), oxygen ($O_2$), and soot were presented as a function of mixture fraction and compared with state relationships based on the idealized reaction of hydrocarbon fuels. The mixture fraction analysis made it possible to rearrange hundreds of species measurements, which were done under various fire conditions and at two locations of the upper layer, in term of the unified parameter, i.e. the mixture fraction. The results also showed that inclusion of soot in the mixture fraction calculation could improve the performance of analysis, especially for the sooty fuels such as heptane and toluene.

• Fire Science and Engineering
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• v.32 no.6
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• pp.74-83
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• 2018

In order to secure safety and improve work efficiency of forest firefighting crews, performance evaluation criteria for safety gloves were developed. Since the standard for forest firefighting safety gloves is not available in Korea, we started the study based on the standard for firefighting safety gloves operated by KFI. 12 test items were selected excluding 5 test items out of the 17 test items through the consultation of stakeholders and the review of foreign standards. Two types of general safety gloves used by forest firefighting crews and one firefighting gloves were tested by applying KFI standard and the results were compared. Materials such as nylon or polyurethane which are weak to fire are not suitable for forest firefighting safety gloves. We compared the criteria of KFI, ISO 16073, NFPA 1977, NFPA 1971 and BS EN 659, and finally selected 12 test items and acceptance criteria suitable for the work environment of forest firefighting crews in Korea.

• Fire Science and Engineering
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• v.17 no.1
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• pp.76-84
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• 2003

This study was designed to investigate fire characteristics of the plastics insulating materials such as a polystyrene foam, polyurethane foam, and polyethylene foam, which is used an insulating materials i3t workplace. The fire characteristics of plastic insulating materials were carried out from the Cone Calorimeter test according to ISO 5660. The experimental materials used were commercial plastic insulating materials by products and their composition is not disclosed by the manufacturer. As the results of this study; the heat release rate of plastic insulating materials was increased with increasing density and heat flux. The peak heat release rate and the average heat release rate for the polyethylene foam in insulating materials were showed the highest, and the peak heat release rate for the polyethylene foam was the highest. The standard of heat release rate with a kind of products and heat flux of irradiance to prevent fire by plastic insulating materials was suggested.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.339-347
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• 2014

Floor impact sound in high-rise apartment building became one of social problems. A lot of civil complaints on floor impact sound occur continuously and the number of disputes between neighbors in small and aged apartment buildings is increasing. Interests on heavy-weight impact sound pressure level measurement and evaluation method is increased. Previous study reported that heavy-weight impact sound level was changed by the sound field condition of receiving reverberation chamber. In this study, heavy-weight impact sound pressure level change by the receiving sound field condition was measured in standard test facility and mock-up test room. These two experimental conditions were designed to simulate averaged living room of common apartment units. By the change of sound absorption power in receiving room, heavy-weight impact sound pressure level in most of frequency bands were changed in standard test facility and mock-up room. Normalized maximum sound pressure level regulated in ISO 16032 showed wider range of heavy/soft impact sound pressure level. Heavy/soft impact sound pressure level change was became smaller by the application of standardized maximum sound pressure level and ISO/CD 10140-3 Amd 2 method. In the case of standardized maximum sound pressure level, absolute sound pressure level changed. From these results, receiving sound field correction method regulated in ISO/CD 10140-3 Amd 2 is needed for the precision measurement and evaluation of heavy-weight impact sound.

• Advances in Computational Design
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• v.1 no.1
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• pp.105-117
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• 2016

The objective of this work is to study the restraining effect in fire resistance of framed structures and to evaluate the global response of reinforced concrete frames when exposed to fire based on advanced finite element method. To study the response a single portal frame is analyzed. The effect of floor slab on this frame is studied by modeling a beam-column-slab assembly. The evolution of temperature distribution, internal stresses and deformations of the frame subjected to ISO 834 standard fire curve for both the frames are studied. The thermal and structural responses are evaluated and a comparison of results of individual members and entire structure is done. From the study it can be seen that restraining forces has significant influence on both stresses and deflection and overall response of the structure when compared to individual structural member. Among the various structural elements, columns are the critical members in fire and failure of column causes the failure of entire structure. The fire rating of various structural elements of the frame is determined by various failure criteria and is compared with IS456 2000 tabulated fire rating.

• 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.