• Fire Science and Engineering
• /
• v.25 no.1
• /
• pp.78-84
• /
• 2011

Recent researches of the fire resistance in concrete focus on how to secure relevant functions in the high strength concrete. However, the demand of normal strength concrete less than 40 MPa takes most of the total concrete demand. Therefore, fire resistance study needs to cover not only high strength concretes but also normal strength concretes. This study evaluated the fire resistance performance of 40 MPa concrete columns, taking the concrete covering thickness and the size of section as variables. Consequently, the fire resistance performance improved as the section size and the covering thickness became larger.

• Journal of Korean Society of Steel Construction
• /
• v.23 no.1
• /
• pp.51-59
• /
• 2011

Although an uncoated CFT column with a high axial-force ratio can be used to secure fire resistance for two hours or less in low-rise buildings, it does not satisfy the three-hour-long fire resistance required in high-rise buildings. Accordingly, so that the uncoated CFT column could be used for high-rise buildings, additional measures for the improvement of its fire resistance should be proposed. In this regard, the use of a Double CFT column as a measure for improving the fire resistance of the uncoated CFT column was proposed in this paper. A fire resistance test was conducted on an uncoated CFT column and a Double CFT column in real scale, under a load. Through such test, the effect of the Double CFT column on fire resistance was evaluated and then compared with that of a variant shape of the cross-section of a steel column.

• Journal of the Korea Concrete Institute
• /
• v.22 no.2
• /
• pp.229-235
• /
• 2010

In this study, fire resistance performance of high strength concrete specimen with fireproof gypsum board was investigated for possible use in upgrading fire-resistant performance of the existing building and repair of fire damaged structures. Fire test of eight identical high strength concrete columns were carried out for 180 minutes in accordance with ISO-834. The temperature distributions in longitudinal reinforcement and concrete temperature at various depths were recorded. The fireproof performance of gypsum board and explosive spalling of concrete were observed. The specimens with 15 mm thick twoply fireproof gypsum board spalled after gypsum board crumbled regardless of fastening methods. However, when the thickness of fireproof gypsum board was more than 30 mm, it was possible to prevent the explosive spalling and control the rebar temperature. Although the effect of cover thickness could not be compared because the explosive spalling occurred, there seemed to be no difference in insulation efficiency.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.945-948
• /
• 2008

Fire resistance is a measure of the ability of building element to resist a fire. For concrete columns, the fire resistance depends on many factors, including strength, density, and moisture content of concrete, fire intensity, column size and shape, reinforcement detail, loading condition, and aggregate type etc. However, it is well-known that the high strength concrete (HSC) is more susceptible to spalling than normal strength concrete (NSC) and the behaviour of HSC column exposed to fire is significantly affected by the spalling. Recently, as one of the measures to reduce the spalling of HSC, incorporating polypropylene(PP) fiber has been investigated and successfully used in construction fields. However, the establishment of assessment method on the fire resistance of HSC column is very important as well as the improvement of fire performance of HSC. In this study, the variations on the fire resistance of HSC column with assessment methods was studied for the columns controlled the concrete spalling by PP fiber.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.11 no.4
• /
• pp.560-567
• /
• 2023

This study is part of the research on fire-resistant materials to prepare for changing fire behavior, oyster shell and egg shell, which are natural calcium carbonate materials, were substituted as fine aggregates. The purpose of this study was to evaluate the strength and fire resistance performance according to the substitution rate, and to provide data for use as fire resistance material. Oyster shells and egg shells were substituted with 10~50 % of the fine aggregate, respectively, and tested for strength and Simplified heating according to the KS test method. Although the strength of OS was measured to be higher than that of ES, the backside temperature was also measured to be higher. As a result, it is recommended to use fireproof boards with OS where strength performance is required, such as explosive fires, Where high fire resistance performance is required, such as high-temperature fires over 1000 ℃, fireproof boards with ES can be selected according to the application.

• Journal of Korean Society of Steel Construction
• /
• v.26 no.4
• /
• pp.323-334
• /
• 2014

In this paper, experimental program and associated numerical study were carried out to evaluate the fire resistance of unprotected concrete-filled rectangular steel tubular (CFT) columns subjected to the standard fire. The key testing parameters included the length effect, the load ratio, and the sectional dimensions of the CFT columns. Temperature distribution and axial deformation of the CFT column specimens were measured and analyzed. Rather early local buckling of steel tubes was observed in all the specimens. This caused subsequent load transfer from steel tube to concrete, and eventually triggered concrete crushing, or complete loss of the load bearing capacity of the column. This implies that the limit state of local buckling as well as overall flexural buckling should be incorporated in fire design procedure. As expected, the fire resistance time of specimen with higher load ratio consistently lessened. The prediction of fire resistance time of unprotected CFT columns based on the limiting steel temperature in current design codes or the formula proposed by previous studies is slightly conservative compared to the fire test results available. To establish the finite element analysis model that can be used to predict the thermal and structural behaviour of unprotected CFT columns in fire, the fully coupled thermal-stress analysis was also tried by using the commercial code ABAQUS. The numerical results showed a reasonable global correlation with the experimental results.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.804-807
• /
• 2008

Recently, with the increase of high rise and huge scale building construction, the use of high strength concrete has been increasing. High strength concrete has dense pore structure, which is susceptible to be damaged due to fire attack. For this, many researchers provide proper fire endurance method. In this paper, to provide the priority for selecting fire endurance method in high strength concrete execution, AHP technique is applied based on expert questionnaire. Fire endurance performance efficiency and ordinary performance efficiency was selected for level 1. Fire endurance performance efficiency had larger weight than ordinary one.

• Fire Protection Technology
• /
• s.35
• /
• pp.24-30
• /
• 2003

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2004.10a
• /
• pp.469-474
• /
• 2004

• Fire Protection Technology
• /
• s.38
• /
• pp.14-23
• /
• 2005