• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.169-170
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• 2014

In this study, a general strength concrete member is produced and its hydrothermal temperature is measured. It is intended to present the basic data for establishment of fire resistance performance assessment and review of safety against fire by comparing the data values of slab fire resistance experiment and the numerical analysis model. The value obtained by measuring the hydrothermal temperature of the concrete after heating the concrete designed to have general strength (30 Mpa) for 3 hours in accordance with the ISO 834 Heating Curve is compared with the value obtained from a thermal conduction analysis. As a result of the comparison, though there is a little difference, it is thought that fire behaviors can be predicted in the future if the movement of moisture and the added evaporation speed are taken into account.

• 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.

• Coupled systems mechanics
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• v.9 no.2
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• pp.163-182
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• 2020

Coupled thermo-mechanical analysis of reinforced concrete slab at elevated temperatures from a fire accounting for nonlinear thermal parameters is carried out. The main focus of the paper is put on a one-way continuous reinforced concrete slab exposed to fire from the single (bottom) side as the most typical working condition under fire loading. Although contemporary techniques alongside the fire protection measures are in constant development, in most cases it is not possible to avoid the material deterioration particularly nearby the exposed surface from a fire. Thereby the structural fire resistance of reinforced concrete slabs is mostly influenced by a relative distance between reinforcement and the exposed surface. A parametric study with variable concrete cover ranging from 15 mm to 35 mm is performed. As the first part of a one-way coupled thermo-mechanical analysis, transient nonlinear heat transfer analysis is performed by applying the net heat flux on the exposed surface. The solution of proposed heat analysis is obtained at certain time steps of interest by α-method using the explicit Euler time-integration scheme. Spatial discretization is done by the finite element method using a 1D 2-noded truss element with the temperature nodal values as unknowns. The obtained results in terms of temperature field inside the element are compared with available numerical and experimental results. A high level of agreement can be observed, implying the proposed model capable of describing the temperature field during a fire. Accompanying thermal analysis, mechanical analysis is performed in two ways. Firstly, using the guidelines given in Eurocode 2 - Part 1-2 resulting in the fire resistance rating for the aforementioned concrete cover values. The second way is a fully numerical coupled analysis carried out in general-purpose finite element software DIANA FEA. Both approaches indicate structural fire behavior similar to those observed in large-scale fire tests.

• Journal of Korean Society of Steel Construction
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• v.25 no.2
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• pp.131-139
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• 2013

The object of this paper is to perform the experiments to investigate the relationship of the resistance forces and the failure temperatures on the failure behaviors of H-shaped steel compressive members. H-shaped members(SS400) were used for the test models and the tests for the elevated temperatures were performed by ISO 834 in FILK(Fire Insurers Laboratories of Korea). The local, overall buckling stresses and a yielding stresses for the failure temperatures were compared with the compressive stresses for the loading forces of test models, the yielding strength and elastic modulus reduction factor of the steel at a high temperature were based on the criteria of the EC3(Eurocode 3) Part1.2(1993). The slenderness ratio was fixed by 45.4 and the compressive forces corresponded with 50%, 70% and 80% of the yielding forces at the normal temperatures were chosen for the loading forces of the test models. The failure temperatures of the test models were investigated under three kinds of loading conditions. It was known that the resistance forces have come close to the yielding forces, not the elastic buckling loads evaluated by EC3 at the failure temperatures obtained from the tests which are related to the failure temperatures and the loading stresses.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.101-107
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• 2008

This study investigated fundamental characters of the concrete according to various fiber types and contents and their properties of spatting resistance and residual compressive strength after fire test corresponding to ISO and RABT heating corves. The results were summarized as following. The Flowability was gradually declined as the increase of fiber contents, and it was the most favorable with nylon(NY) fibers. The decrease of air contents due to increasing fiber contents was in order by polypropylene(PP), polyvinyl alcohol(PVA) and NY fibers. The compressive strengths were over 40 MPa at 7 days and 50 MPa at 28 days. It was in order by PVA, PP and NY fibers. For the spatting properties, all specimens were prevented at ISO heating curve. In the other hand, the partial spatting at the surface occurred on the plain without fibers, but it was prevented over 0.10 % of PVA and 0.05 % of PP and NY fibers at the RABT heating curve.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.46-49
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• 2012

지하대공간은 특수한 가연물 및 높은 밀도의 화재하중을 지닌 가연물이 많으나, 국내 내화성능기준은 이를 고려하지 않고 있다. 이에 본 연구는 슬래브실험체를 제작하여 표준가열곡선(ISO834)과 지하대공간의 화재하중을 고려한 화재조건으로 내화실험과 수치해석을 실시하였으며, 그 결과 모든 실험체에서 0.96~1.03로 10%내의 오차범위에 있는 것을 확인 할 수 있었다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.149-150
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• 2018

Recently, a large fire has occurred through a dry bit, which is a flammable exterior material, in Daebong Green Apartment Fire in Uijeongbu in 2015 and Jecheon Sports Center Fire in 2017. In this study, KS F ISO 5660-1 Cone calorimeter experiment was used to examine the fire risk of dry bit. Also, the performance of the repair and reinforcement materials to prevent fire expansion was examined. As a result, the dry bit is likely to be ignited by internal and external flower gardens, and its combustion rate and calorific value are very high. In addition, the performance of heat resistance such as ALC panel and ceramic board as a repair and reinforcement material has been proved. However, the insulation is expected to require further consideration.

• Polymer(Korea)
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• v.26 no.2
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• pp.260-269
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• 2002

The fire resistance of particulate polypropylene composite systems were investigated by using various reinforced particles such as zeolite, talc, $CaCO_3$ particles. In this study, The effect of particle size on the thermal properties of composite and the effect of reinforced particles on the fire resistance were studied. The inorganic reinforced particles used in this study were recycled zeolite(average particle diameter=85.34 $mu extrm{m}$), $CaCO_3$ (33.93 $mu extrm{m}$), and talc (18.51 $mu extrm{m}$). The fire resistance of composite systems was thoroughly examined by measuring limited oxygen index (LOI, ASTM D2863) and cone calorimetry (ASTM E1354, ISO 5660). Thermal stability of composite systems was thoroughly examined by measuring TGA. The flame retardants (DBDPO) and reinforced particles reduce the maximum heat release rate (M-HRR) in the order of Talc > $CaCO_3$ > recycled Zeolite. Comparing the cone calorimetry experimental results of the particle reinforced polymer composite system exhibited twice higher efficiency than DBDPO in polypropylene systems, and the LOI also showed similar trends to the cone calorimetry experiments. The optical and scanning electron microscopy techniques were used to investigate the composites ash layer and the core fracture surfaces in the burning process. The reinforcing inorganic particles seemed to accumulate at the surface of ash layer, and subsequently intercept the oxygen transport and heat transfer into the core area.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.70-76
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• 2005

The interior materials of the urban subway car in operation are now being changed to new materials that meet the latest law in effect, the fire safety criteria of the urban railway vehicle. It was well known fact that the composite materials, that were applied to last subway car, were weak on the fire. Contrary to this materials, materials in work have good resistance to the fire. On the paper, To investigate the difference of fire safety level on the subway car, cone calorimeter was used to measure the heat release rate and total heat released according to the ISO 5660. A high radiative heat flux of 50kW/m2 was used to burn out all materials and to simulate the condition of fully developed fire case in the tests.

• Computers and Concrete
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• v.12 no.5
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• pp.717-737
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• 2013

In this study, experiment and numerical analysis were conducted to identify the heat transfer characteristics and behavior of high-strength concrete upon a fire. The numerical analysis was employed to forecast the characteristics and properties of the high-strength concrete upon a fire, which can not be accomplished through a fire test due to the specific conditions and restrictions associated with the test. The result of the numerical analysis was compared with that of the test to verify the reliability of the analysis. In the numerical analysis of the heat transfer characteristics and behavior of 80 and 100 MPa high-strength concrete upon a fire, the commercial software of ABAQUS(V.6.8) was used. It was observed from the experiment that the contraction of the concrete with fiber-cocktail was mitigated by 25~55 % compared with that without fiber-cocktail because the fiber controlled the heat transfer of the concrete and thus improved the fire-resistance performance of the column.