• Journal of the Korean Society of Safety
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• v.25 no.4
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• pp.48-60
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• 2010

The fire resistance performance of 2 RC slabs after exposure to the ISO-834 fire standard without loading has been experimentally investigated. A Comparison is made of the fire resistance performance between RC slabs without PP(polypropylene) fibers and RC slabs with PP fibers. From the fire test results, the presence of PP fibers in RC slabs can reduce spalling and enhance their fire resistance. Until now, the determination of fire resistance of reinforced concrete(RC) slabs has essentially been based on tabulated data. According to ACI 216 code and EUROCODE 2, the design of concrete structures is essentially based on tabulated data for appropriate concrete cover and various fire durations. From the comparison between fire test results and codes, current fire design provisions of codes such as the ACI 216 and the EUROCODE 2 are unconservative for estimating mechanical properties of RC slabs at elevated temperatures.

• Korean Journal of Metals and Materials
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• v.49 no.9
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• pp.671-677
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• 2011

Steel columns used in steel buildings are inclined to lose their strength when exposed to severe fire conditions, so fire resistance is required in most countries to protect against loss of life and building collapses. In Korea, the fire resistance of columns can be obtained by the fire test defined in KS F 2257-1, 7. The fire resistance of a steel column should be evaluated in terms of the column's conditions, such as various section types (H-section, hollow-section), the column's length and boundary conditions, and whether it is fixed or hinged. However, fire testing of steel columns is usually conducted on one standard-sized H-section over 3,000 mm, and the result is used as the column's fire resistance. This is not a reasonable way to ensure that a building can withstand fire conditions. In this study, to evaluate the possibility of calculating the fire resistance of steel columns with material properties of high tensile strength of SS 400, both load-bearing fire tests and calculation of steel temperatures were carried out. The results of temperature calculation were very similar to those obtained by fire test.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.287-298
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• 2018

High strength steels have been widely applied in recent years due to high strength and good working performance. When subjected to fire conditions, the strength and elastic modulus of high strength steels deteriorate significantly and hence the load bearing capacity of structures reduces at elevated temperatures. The reduction factors of mechanical properties of high strength steels are quite different from mild steels. Therefore, the fire design methods deduced from mild steel structures are not applicable to high strength steel structures. In recent ten years, the first author of this paper has carried out a lot of fundamental research on fire behavior of high strength steels and structures. Summary of these research is presented in this paper, including mechanical properties of high strength steels at elevated temperature and after fire exposure, creep response of high strength steels at elevated temperature, residual stresses of welded high strength steel member after fire exposure, fire resistance of high strength steel columns, fire resistance of high strength steel beams, local buckling of high strength steel members, and residual strength of high strength steel columns after fire exposure. The results show that the mechanical properties of high strength steel in fire condition and the corresponding fire resistance of high strength steel structures are different from those of mild steel and structures, and the fire design methods recommended in current design codes are not applicable to high strength steel structures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.179-182
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• 2013

Many kinds of fire-stop sealants have been used for joint sealing, cable penetration part sealing and fireproof structure finishing etc in building sectors which need water-proofing and fire-stop properties. But, fire-stop sealant itself has no specific industry standards in Korea even though there are so many required properties for the application. So, in this study, for the evaluation, we adopted and applied UL standard 94(UL 94) which is commonly used for the fire retardant testing in inflammable materials like plastics and rubbers in electronics industry. In this study, we demonstrated fire resistance properties of each fire-stop sealants which varied with different formulation, thickness and origins available in Korea. Overall, fire stop sealant had better fire resistance performance than normal construction sealant. And the thicker the material, the better the fire resistance performance was. Because there is no national or industry guideline for fire stop sealant itself, each sealant products showed different level of performances under UL94 desigation. Even certain product had very poor fire proof propeties although it claims it can be used for the application.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.187-191
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• 2008

It is necessary to develop a technology for effectively controling explosive spalling of high strength concrete caused increasing construction of high rise building and putting up the fireproof standard of high strength concrete by MLTM (Ministry of Land, Transport and Maritime Affairs). Accordingly, it was investigated basic properties such as slump, air content and compressive strength, and fire resistance properties of high strength concrete using polypropylene fiber for field application as a countermeasure for explosive spalling of concrete on fire in this study, As a test result, it was confirmed that PP fiber is available as fire resistance method of high strength concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05c
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• pp.75-78
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• 2009

It was investigated fire resistance properties and mechanical properties of high strength concrete column using ECC(Engineered Cementitious Composites) permanent form by KS F 2257 Methods of fire resistance test for elements of building construction and compression test for application of precast concrete column method of high rise building in this study. As a test result, it was appeared that ECC permanent form is available as fire resistance method of high strength concrete and new precast concrete construction method for facilitating construction of high rise building.

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

• Steel and Composite Structures
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• v.43 no.3
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• pp.353-362
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• 2022

Bridge fire hazard has become a growing concern over the last decade due to the rapid increase of ground transportation of hazardous materials and resulting fire incidents. The lack of fire safety provisions in steel bridges can be a significant issue owing steel thermal properties that lead to fast degradation of steel properties at elevated temperatures. Alternatively, the development of composite action between steel girders and concrete decks can increase the fire resistance of steel bridges and meet fire safety requirements in some applications. This paper reviews the fire problem in steel bridges and the fire behavior of composite steel-concrete bridge girders. A numerical model is developed to trace the fire response of a typical bridge girder and is validated using measurements from fire tests. The selected bridge girder is composed by a hot rolled steel section strengthened with bearing stiffeners at midspan and supports. A concrete slab sitting on the top of the girder is connected to the slab through shear studs to provide full composite action. The validated numerical model was used to investigate the fire resistance of real scale bridge girders and the effect of the composite action under different scenarios (standard and hydrocarbon fires). Results showed that composite action can significantly increase the fire resistance of steel bridge girders. Besides, fire severity played an important role in the fire behavior of composite girders and both factors should be taken into consideration in the design of steel bridges for fire safety.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.586-595
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• 2012

While the extruded cement panel has many advantages compared to drywall, it has limited applicability in buildings due to its low fire resistance. However, an extruded panel in which the fire resistance has been dramatically enhanced through the addition of a-hemihydrate gypsum is expected to become widely applied as a partition wall or interior material for buildings. To ensure its applicability, certain safety requirements for use, such as the leaning load by residents, the impact by indoor articles, and the fire, need to be taken into consideration. The purpose of this study is to review the impact load resistance, horizontal load resistance, and fire resistance as required safety properties for the partition wall and interior materials of the extruded panel that includes a-hemihydrate gypsum. The results of this study show that the impact load resistance of the extruded panel that includes a-hemihydrate gypsum achieves SD grade for industrial buildings, and the horizontal impact load resistance achieves HD grade for public buildings. In addition, it provides fire-resistance for approximately 7 minutes longer than the existing extruded cement panel. Based on this result, it is confirmed the extruded panel incorporating a-hemihydrate gypsum has adequate safety properties for use as partition wall or interior material.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.1
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• pp.49-57
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• 2008

This study evaluated the flexural properties and fire resistance of polyolefm based structural synthetic fiber reinforced concrete. The effects of differing fiber length, dimension and fiber volume fraction were studied. Flexural and fire resistance test were conducted in accordance with the JCI SF-4 and RABT time heating temperature curve, respectively. The Flexural test results indicated that the polyolefln based structural fiber reinforcement showed an ability to increase the flexural toughness and good fire resistance significantly(as compared to steel fiber reinforcement).