• Steel and Composite Structures
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• v.15 no.6
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• pp.705-724
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• 2013

The behaviour of steel column at elevated temperature is significantly different than that at ambient temperature due to its changes in the mechanical properties with temperature. Reported literature suggests that steel column may become vulnerable when exposed to fire condition, since its strength and capacity decrease rapidly with temperature. The present study aims at investigating the lateral load resistance of non-insulated steel columns under fire exposure through finite element analysis. The studied parameters include moment-rotation behaviour, lateral load-deflection behaviour, stiffness and ductility of columns at different axial load levels. It was observed that when the temperature of the column was increased, there was a significant reduction in the lateral load and moment capacity of the non-insulated steel columns. Moreover, it was noted that the stiffness and ductility of steel columns decreased sharply with the increase in temperature, especially for temperatures above $400^{\circ}C$. In addition, the lateral load capacity and the moment capacity of columns were plotted against fire exposure time, which revealed that in fire conditions, the non-insulated steel columns experience substantial reduction in lateral load resistance within 15 minutes of fire exposure.

• Steel and Composite Structures
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• v.19 no.3
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• pp.661-678
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• 2015

Buckling Restrained Braces (BRB) have been widely used in the construction industry as they utilize the most desirable properties of both constituent materials, i.e., steel and concrete. They present excellent structural qualities such as high load bearing capacity, ductility, energy-absorption capability and good structural fire behaviour. The effects of size and type of filler material in the existed gap at the steel core-concrete interface as well as the element's cross sectional shape, on BRB's fire resistance capacity was investigated in this paper. A nonlinear sequentially-coupled thermal-stress three-dimensional model was presented and validated by experimental results. Variation of the samples was described by three groups containing, the steel cores with the same cross section areas and equal yield strength but different materials (metal and concrete) and sizes for the gap. Responses in terms of temperature distribution, critical temperature, heating elapsed time and contraction level of BRB element were examined. The study showed that the superior fire performance of BRB was obtained by altering the filler material in the gap from metal to concrete as well as by increasing the size of the gap. Also, cylindrical BRB performed better under fire conditions compared to the rectangular cross section.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.25-31
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• 2016

This paper has analyzed the structure, applicable regulations and the resistance characteristics of insulation ring type of CSST (Corrugated Stainless Steel Tubing for Gas). With the flammability test conducted in accordance with KS C IEC 60811-1-1, the evaluation of insulation resistance, temperature characteristics, and reliability has been conducted. An insulation ring type CSST consists of protective coating, tube, nut, insulation ring, packing, socket, and ball valve. Connecting an insulation ring type CSST to gas tubings for gas appliance is not permitted, moreover, the product shall be installed inside a sleeve pipe in case of buried installation such as the ceiling. Damages on protective coating and tube were detected when fire was applied to the test sample with a portable torch for 60 seconds. The insulation resistance of a normal product was $49.59M{\Omega}$, while that of the product completed the flammability test reduced to $9.21M{\Omega}$. The mean insulation resistance within the confidence Interval of 95% using the mini tap program 17 was $49.59M{\Omega}$ and the mean insulation resistance within the confidence interval reduced to $9.21M{\Omega}$. In the normal distribution analysis of 95% confidence interval, the value-P of the normal product was stable at 0.075 and AD(Anderson-Darling) statistic value was turned out to be 0.063, which is very normal, and the standard deviation was analyzed as 0.2586. The value P of the product completed the flammability test resulted in 0.005, the AD was 1.355 and the standard deviation reduced to 0.07908.

• Fire Science and Engineering
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• v.24 no.2
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• pp.21-30
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• 2010

We have test chemical resistance and flame retardant properties of chemical protective clothing Fabrics by the ASTM and ISO standard methods. The flame retardant test results show that polyethylene is poor in flame resistance but fluoroelastomer add to decabrom is excellent in flame resistance. Especially, nowadays heat protective clothing for firefighters, which is aluminized film layers laminated to aramid fabric, show the excellent flame resistance. However, the chemical resistance test results show that aluminium is high corrosive in 4M NaOH solution alone. The problem of corrosion can be overcome by employing multiple barrier film. Also, based on the result of flame retardant test, duel skin of polymer barrier film add to aluminum film and single skin of fluorinated rubber with flame retardant materials seems to be fit for the chemical protective clothing. Also the thermal protection and heat transfer test results show that TPP and HTI is increased assured that the continued study on fire risk assessment & chemical resistance of chemical protective clothing fabrics will contribute to the upgrade the performances of chemical protective clothing fabrics.

• Magazine of the Korea Concrete Institute
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• v.18 no.5 s.94
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• pp.10-13
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• 2006

• Fire Science and Engineering
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• v.21 no.3
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• pp.47-55
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• 2007

The mechanical properties such as 0.2% and 1% offset proof strength and elastic modulus are essential for a structural steel structure when the structure would be evaluated and designed to identify the performance of the structural stability exposed to fire condition. To obtain the mechanical properties for the structural steels at high temperature which are consisted of ordinary and marine ones, the tensile tests at various high temperatures had been conducted with two kinds of specimen of general structural steel SS 400 and welded steel SM 490 at the range of room temperature to $900^{\circ}C$ at interval of $100^{\circ}C$.

• Computers and Concrete
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• v.18 no.6
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• pp.1097-1112
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• 2016

Fire loading causes a critical collapse of RC (Reinforced Concrete) Structures since the embedded steels inside are relative week against high elevated temperature. Several numerical frameworks for fire resistance have been proposed, however they have limitations such as unstable convergence and long calculation period. In the work, 2-D nonlinear FE technique is proposed using Galerkin method for RC structures under fire loading. Closed-form element stiffness with a triangular element is adopted and verified with fire test on three RC slabs with different fire loading conditions. Several simulations are also performed considering fire loading conditions, water contents, and cover depth. The proposed numerical technique can handle time-dependent fire loading, convection, radiation, and material properties. The proposed technique can be improved through early-aged concrete behavior like moisture transport which varies with external temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.647-652
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• 1997

Repair and rehabilitation of existing structures is becoming a major part of construction, both in the industrially developed and developing countries. Advanced high strength composites are being utilized more and more for these applications because they are much stronger than steel, non-corrosive, and light. The light weight reduces the construction cost and time sustantially. The fibers are normally made of aramid, carbon, or glass and the binders are typically epoxies or esters. One major disadvantage of these composites is the vulnerability to fire. In most instance, the temperature cannot exceed $300^{\cire}C$. Since carbon and glass can substain high temperatures, an inorganic polymer is being evaluated for use as a matrix. The matrix can sustain more than $1000^{\cire}C$. The results reported in this paper deal with the mechanical properties of carbon composites made with the inorganic polymer and the behavior strengthened reinforced concrete beams. The results indicate that the new matrix can be successfully utilized for a number of applications.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.537-540
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• 2008

Tunnel structures are constructed even longer and more extensive these days than they were in the past. Because of this reason, breaking out a large scale of fire in tunnel structures is frequently. Recently, a noticeable event is reported that the temperature of inside of tunnel rises significantly when an oil car detonated in the tunnel and it reached 1,350$^{\circ}$C. It did damage to people who used the tunnel at that time and caused many demaged parts of tunnel to recover. To improve a fire resistance of tunnel, many methods are studied focused refractory concrete and mortar. This study deals with refractory mortar and is a part of initial basic step. In this study mechanical properties are considered before fire resistance test. As result of test for examination of mechanical properties, it is considered that a consistency and strength of refractory mortar in this study are suitable to construct.

• 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.