• Fire Science and Engineering
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• v.27 no.3
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• pp.20-29
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• 2013

To investigate numerically the effects of geometry and location of vertical opening on the thermal and chemical fire characteristics in full-scale under-ventilated compartment fires, the ventilation factor ($A\sqrt{h}$) to estimate a theoretical maximum inflow of ambient air and the mass loss rate in a heptane pool fire were fixed for all cases. It was shown that variations in door geometry affected significantly the change in thermal and chemical characteristics inside the compartment. Variations in window location resulted in the complex change in additional fire characteristics including the fire duration time and recirculating flow structure. These results were analyzed in details by the multi-dimensional flow and fire characteristics including the vent flow and fuel/air mixing phenomena.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.32-35
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• 2004

In recent years a number of catastrophic tunnel fires, the Euro tunnel, the Mont Blanc tunnel, the Tauem tunnel and the Gotthard tunnel, have occurred and inflicted serious damages to European countries. If a fire occurs in shield tunnels, the reinforced concrete segment linings playing as an important structural member is expected to damage severely and finally can be caused the collapse of tunnel. The purpose of this study is to evaluate the performance of concrete segment lining under heat exposure and to obtain information to assist a new technical approach to fighting fires in tunnels. In order to evaluate the fire-resistance performance of concrete segment by adding Polypropylene fibers, fire tests using the RABT heat-load curve is carried out. The temperature rise of this curve is very rapid up to $1200^{\circ}C$ within 5 minutes, and duration time of the $1200^{\circ}C$ exposure is 55 minutes. From the fire test, it was found that the explosive spalling was rapidly reduced by adding polypropylene fibers and this method is considered as an effective fireproof material to upgrade fire safety in tunnels economically.

• Journal of Hydrogen and New Energy
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• v.18 no.3
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• pp.348-355
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• 2007

To grasp a feasibility of back fire control by valve overlap period, back fire limit equivalence ratio was estimated with valve overlap period which has the same supply energy and positive intake pressure as valve overlap period $300^{\circ}\;CA$. As the result, it was shown that the smaller valve overlap period has the higher back fire limit equivalence ratio under valve overlap period $300^{\circ}\;CA$ as well as VOP $0^{\circ}\;CA$. This result means that expansion of back fire equivalence ratio by decreasing valve overlap period was caused by decrease of back flow duration of flame from in-cylinder to intake port than decrease of lower supply energy.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.299-311
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• 2018

As engineered timber such as Glulam is seeing increasing use in tall timber buildings, building codes are adapting to allow for this. In order for this material to be used confidently and safely in one of these applications, there is a need to understand the effects that fire can have on an engineered timber structural member. The post-fire resilience aspect of glulam is studied herein. Two sets of experiments are performed to consider the validity of zero strength guidance with respect to short duration fire exposure on thin glulam members. Small scale samples were heated in a cone calorimeter to different fire severities. These samples illustrated significant strength loss but high variability despite controlled quantification of char layers. Large scale samples were heated locally using a controlled fuel fire in shear and moment locations along the length of the beam respectively. Additionally, reduced cross section samples were created by mechanically carving a way an area of cross section equal to the area lost to char on the heated beams. All of the samples were then loaded to failure in four-point (laterally restrained) bending tests. The beams that have been burnt in the shear region were observed as having a reduction in strength of up to 34.5% from the control beams. These test samples displayed relatively little variability, apart from beams that displayed material defects. The suite of testing indicated that zero strength guidance may be under conservative and may require increasing from 7 mm up to as much as 23 mm.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.673-680
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• 2022

Modular construction is recognized as a construction method with various advantages, such as shortening the construction duration, achieving quality control through factory production, ease of maintenance, and reduced construction costs due to reduced weight of materials. However, despite efforts by the modular industry and government to activate modular construction, it has rarely been established in the domestic market. Currently, there are technical limitations to the modular construction fire resisting technology applied to general buildings. The lack of access to modular construction fire resistance regulation is considered a major factor. In this study, the current status and problems with modular construction fire resistance regulation, a significant hindrance factor, were considered to activate modular construction. This study is intended to present a direction for institutional improvement in modular construction fire resistance and a direction for research and development.

• Fire Science and Engineering
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• v.27 no.3
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• pp.8-13
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• 2013

In case of fire in a high-rise building fire can be easily spread along the building external walls dramatically if the flame comes out through broken windows. There are a few effective methods to prevent the fire spread at the moment. One is using a fire resistance window, and the other is using a window sprinkler that discharges water to resist flame in case of fire. In this study a window sprinkler which is installed on top of windows and prevents fire by discharging water when its heat-responsive element opens was tested using a large scale furnace in accordance with the standard temperature-time graph. Test result showed that one window sprinkler was able to protect a 2,400 mm wide window from fire for 2 hours and the window backside's temperature locally increased up to $126^{\circ}C$ but kept stable around $100^{\circ}C$ for the test duration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5910-5916
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• 2011

Surface area of the steel member exposed to fire differs according to type and size of the section and the kind of the member, which shows a big difference in the temperature rise of the steel by fire. The section factor ($H_p$/A) is determined by factors such as type, size, and member of the steel and type of the fire protection material, and it is the criteria in determining thickness of the fire protection material. This study showed that the size of the steel increase regardless of the steel type, the section factor decrease. In the results on fire protection thickness of the steel according to the section factor, the efficiency of 1 hour fire protection was lower from 30 to 50% than the criteria. And there is the member, which have the thickness lower the minimum 27% in 2 hour fire protection, but it generally approached in the criteria. In case of H-shape steel, the efficiency of 3 hour fire protection was suitable for the criteria, but rectangular hollow steel section and circular hollow steel section were higher (5.0-17.5%) than the criteria.

• Computers and Concrete
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• v.29 no.4
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• pp.263-278
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• 2022

Limestone calcined clay cement (LC³) is a low carbon alternative to conventional cement. Literature shows that using limestone and calcined clay in LC³ increases the thermal degradation of LC³ pastes and can increase the magnitude of fire risk in LC³ concrete structures. Higher thermal degradation of LC³ paste prompts this study toward understanding the fire performance of LC³ concrete and the associated magnitude of fire risk. For fire performance, concrete prepared using ordinary Portland cement (OPC), pozzolanic Portland cement (PPC) and LC³ were exposed to 16 scenarios of different elevated temperatures (400℃, 600℃, 800℃, and 1000℃) for different durations (0.5 h, 1 h, 2 h, and 4 h). After exposure to elevated temperatures, mass loss, residual ultrasonic pulse velocity (rUPV) and residual compressive strength (rCS) were measured as the residual properties of concrete. XRD (X-ray diffraction), TGA (thermogravimetric analysis) and three-factor ANOVA (analysis of variance) are also used to compare the fire performance of LC³ with OPC and PPC. Monte Carlo simulation has been used to assess the magnitude of fire risk in LC³ structures and devise recommendations for the robust application of LC³. Results show that LC³ concrete has weaker fire performance, with average rCS being 11.06% and 1.73% lower than OPC and PPC concrete. Analysis of 106 fire scenarios, in Indian context, shows lower rCS and higher failure probability for LC³ (95.05%, 2.22%) than OPC (98.16%, 0.22%) and PPC (96.48%, 1.14%). For robust application, either LC³ can be restricted to residential and educational structures (failure probability <0.5%), or LC³ can have reserve strength (factor of safety >1.08).

• Journal of Korean Society of Steel Construction
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• v.22 no.6
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• pp.523-532
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• 2010

Concrete-filled square steel tube (CFT) columns have inherently high fire resistance and load-bearing capacity. Nevertheless, it is sometimes necessary to improve their fire resistance using external fire protection. This paper presents the experimental results of the temperature distribution of CFT columns with fire protection. A fire load test was carried out by exposing small-scale specimens to heat in an electric furnace that was especially built for testing loaded columns. The temperature distribution of CFT columns under constant axial loads was determined, as were its significant parameters, such as the types of fire protection and thickness, the thickness of the square CFT, and the fire duration times. The results of this study showed the temperature distribution of each specimen of the electric furnace and the temperature distribution properties of concrete and steel. In addition, the axial displacement and local buckling behavior of CFT columns based on temperature changes was observed.

• Structural Engineering and Mechanics
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• v.50 no.6
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• pp.755-772
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• 2014

A simplistic approach towards evaluation of complete load deflection response of Reinforced Concrete (RC) flexural members under post fire (residual) scenario is presented in this paper. The cross-section of the RC flexural member is divided into a number of sectors. Thermal analysis is performed to determine the temperature distribution across the section, for given fire duration. Temperature-dependent stress-strain curves for concrete and steel are then utilized to perform a moment-curvature analysis. The moment-curvature relationships are obtained for beams exposed to different fire durations. These are then utilized to obtain the load-deflection plots following pushover analysis. Moreover one of the important issues of modeling the initial stiffness giving due consideration to stiffness degradation due to material degradation and thermal cracking has also been addressed in a rational manner. The approach is straightforward and can be easily programmed in spreadsheets. The presented approach has been validated against the experiments, available in literature, on RC beam subjected to different fire durations viz. 1hr, 1.5hrs and 2hrs. Complete load-deflection curves have been obtained and compared with experimentally reported counterparts. The results also show a good match with the results obtained using more complicated approaches such as those involving Finite element (FE) modeling and conducting a transient thermal stress analysis. Further evaluation of the beams during fire (at elevated temperatures) was performed and a comparison of the mechanical behavior of RC beams under post fire and during fire scenarios is made. Detailed formulations, assumptions and step by step approach are reported in the paper. Due to the simplicity and ease of implementation, this approach can be used for evaluation of global performance of fire affected structures.