scholarly journals Application of the Standard Fire Curve for Expressing Natural Fires for Design Purposes

2008 ◽  
pp. 145-145-15 ◽  
Author(s):  
U Wickström
Keyword(s):  
Natural Fires ◽  
Standard Fire ◽  
Fire Curve ◽  
Standard Fire Curve

scholarly journals Spalling Resistance of Fiber-Reinforced Ultra-High-Strength Concrete Subjected to the ISO-834 Standard Fire Curve: Effects of Thermal Strain and Water Vapor Pressure

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3792
Author(s):  
Taegyu Lee ◽  
Gyuyong Kim ◽  
Gyeongcheol Choe ◽  
Euichul Hwang ◽  
Jaesung Lee ◽  
...  
Keyword(s):  
High Strength Concrete ◽  
Pore Formation ◽  
Water Vapor Pressure ◽  
Thermal Strain ◽  
High Strength ◽  
Strength Concrete ◽  
Standard Fire ◽  
Fire Curve ◽  
Standard Fire Curve ◽  
Polyethylene Fibers

The prevention and mitigation of spalling in high-strength concrete (HSC) rely on mixing polypropylene (PP) as an additive reinforcement. The dense internal structures of ultra-high-strength concrete (UHSC) result in risks associated with a high thermal stress and high water vapor pressure. Herein, the effects of pore formation and thermal strain on spalling are examined by subjecting fiber-laden UHSC to conditions similar to those under which the ISO-834 standard fire curve was obtained. Evaluation of the initial melting properties of the fibers based on thermogravimetric analysis (TGA) and differential thermal analysis (DTA) demon strated that although nylon fibers exhibit a higher melting point than polypropylene and polyethylene fibers, weight loss occurs below 200 °C. Nylon fibers were effective at reducing spalling in UHSC compared to polypropylene and polyethylene fibers as they rapidly melt, leading to pore formation. We anticipate that these results will serve as references for future studies on the prevention of spalling in fiber-reinforced UHSC.

Comparison Study of Fire Resistance According to Differences of Length of H-Section Made of Submarine Structural Steels

2014 ◽  
Vol 909 ◽  
pp. 8-11
Author(s):  
In Kyu Kwon
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Structural Stability ◽  
Fire Resistance ◽  
Structural Steels ◽  
Rapid Decrease ◽  
Comparison Study ◽  
Standard Fire ◽  
Fire Curve ◽  
Standard Fire Curve

Submarine structural steels, such as SM 400, SM 490, and SM 520, have the same structural properties and same grades as general structural steels, but those have better weldability than general structural steels. For that reason, their usage is increasing. However, their fire resistance is not well defined, except for individual fire resistance, such as column and beam. The fire resistance of H-section made of submarine structural steels can be applied with various column lengths. The fire resistance of them is not clear to engineers and residents. To determine the fire resistance, in this paper an analysis was conducted using their mechanical properties at high temperature and related theories with a standard fire curve. As the strength of submarine structural steels is increased, the structural stability showed a rapid decrease while the longer the length of column, the less structural stability of the column represented.

Simulating Post-Earthquake Fire Loading in Conventional RC Structures

2017 ◽  
pp. 425-444
Author(s):  
Behrouz Behnam
Keyword(s):  
Sequential Analysis ◽  
Pushover Analysis ◽  
Rc Buildings ◽  
Rc Structures ◽  
Standard Fire ◽  
Urban Buildings ◽  
Fire Loads ◽  
Fire Curve ◽  
Fire Loading ◽  
Standard Fire Curve

Post-earthquake fire (PEF) is one of the most complicated problems resulting from earthquake, presenting a serious risk to urban buildings. As most standards and codes ignore the possibility of PEF, buildings are too weak under PEF loads. This chapter is to investigate the effects of PEF loads on partially damaged RC buildings located in urban regions. To do that, a methodology named sequential analysis is introduced here via which the structural performance at various performance levels is evaluated under fire and PEF scenarios. Numerically, in order to simulate the earthquake loads, conventional pushover analysis is employed, with an explanation presented in the chapter to introduce the pushover analysis, its advantages and its limitations. To simulate the fire loads, standard fire curve (ISO 834) is used for simplicity.

Comparison Study of Structural Stabilities for H-Section Columns Built with Ordinary Grade Strength Structural Steels According to Boundary Conditions and Lengths at High Temperature

2014 ◽  
Vol 937 ◽  
pp. 424-427
Author(s):  
In Kyu Kwon
Keyword(s):  
Boundary Condition ◽  
High Temperature ◽  
Boundary Conditions ◽  
Fire Resistance ◽  
Structural Steels ◽  
Structural Members ◽  
Steel Buildings ◽  
Standard Fire ◽  
Fire Curve ◽  
Resistance Performance

Fire resistance performance of structural members has been evaluated from each singular section and standard fire curve since the beginning of fire tests. However, the need of the exact fire resistance of H-section columns applied in the steel buildings has increased. The main reason for this is there is a difference between the conditions being conducted during the fire test and that from real situation. In this paper, the structural stability of H-section column made of an ordinary strength grade structural steels, SS 400, SM 400, and SM 490 at high temperature were evaluated and compared with boundary conditions and column’s length. This was done in order to suggest a new guideline for the application of fire protective materials in steel column in which the boundary conditions and column lengths are different from that tested with hinge to hinge and 3500 mm. The findings from this study showed hinge to hinge boundary condition was more conservative. And fire resistance performance of longer columns in the case of hinge to fixed and fixed to fixed boundary condition than from 3500 mm and hinge to hinge boundary condition can sustain at high temperature without adding fire protective materials.

Fire Performance of Reinforced Concrete Beams Strengthened with CFRP Sheets Bonded with an Inorganic Adhesive

2011 ◽  
Vol 255-260 ◽  
pp. 574-579 ◽  
Author(s):  
Fu Xiong Wan ◽  
Wen Zhong Zheng
Keyword(s):  
Reinforced Concrete ◽  
Steel Structure ◽  
Reinforced Concrete Beams ◽  
Bottom Surface ◽  
Rc Beams ◽  
Cfrp Sheets ◽  
Standard Fire ◽  
Fire Curve ◽  
Fireproof Coating ◽  
In Fire

Considering softening temperatures of ordinary organic epoxy adhesives are too low, this study develops an inorganic adhesive which strength at 600°C is not lower than that at normal room temperature. Four reinforced concrete (RC) beams strengthened with CFRP sheets bonded with the inorganic adhesive are tested. The fire protection of the CFRP sheets is done using the thick-type fireproofing coatings for tunnel (TFCT) and steel structure (TFCSS) respectively. All specimens are tested in the furnace together. Specimens are exposed to fire for 1.5 hours in according to the ISO834 standard fire curve, and then naturally cooled for 1 hour. CFRP sheets at center point of bottom surface of beams are 300~470°C, and the corresponding displacements at mid-span are 1/1400~1/318 of the actual span. The CFRP sheets keep a good state and are tightly bonded on RC beams by the inorganic adhesive after fire. Temperature and deformation are analyzed by ABAQUS, and the simulation and measured results are in good agreement. The results indicate that, under the protection of fireproof coating, the CFRP sheets work well in cooperation with RC beams and slabs during fire. TFCSS is inferior to TFCT because the former is easier to drop and crack in fire. Analysis method of the finite element supplies a good way to temperature field and deformation calculation of structures in fire.

Preliminary Research on Mechanical Behavior of Steel Frame Filled with Steel Plate Shear Wall after Exposure to Overall Stage of Fire

2013 ◽  
Vol 351-352 ◽  
pp. 90-94
Author(s):  
Xue Kun Liao ◽  
Fang Fang Wei ◽  
Li Hua Qu
Keyword(s):  
Steel Plate ◽  
Shear Wall ◽  
Steel Frame ◽  
Analysis Model ◽  
Steel Plate Shear Wall ◽  
Finite Element Software ◽  
Whole Process ◽  
Standard Fire ◽  
Fire Curve ◽  
Heating Up

For a further study on the fire-resistant performance of steel plate shear wall under overall stage of fire, a numerical analysis model of steel frame filled with steel plate shear wall was built with the finite element software ANSYS. The stress and displacement distribution at different moments were calculated through the thermal structural coupling analysis acording to ISO-834 standard fire curve, by reasonable selection of the thermal parameters, which showed the highest temperature appeared on the heated side of the beam in the process of heating up, while the highest temperature in the stages of cooling and natural cooling appeared in the column-beam connection; The temperature of structure was elevated for 11minutes, then dropped for 64.5minutes and finally the structure was cooled in the air for 60.5minutes. The whole process shows that the lateral load-bearing capacity of the steel frame filled with steel plate shear wall was reduced by about 30 percent, compared to room temperature.

scholarly journals A novel approach to determine charring of wood in natural fire implemented in a coupled heat-mass-pyrolysis model

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Pečenko ◽  
Tomaž Hozjan
Keyword(s):  
Physical Phenomenon ◽  
Model Accuracy ◽  
Mass Model ◽  
Natural Fire ◽  
Natural Fires ◽  
Standard Fire ◽  
Novel Approach ◽  
Pyrolysis Model ◽  
Front Temperature

AbstractThe paper presents a novel approach to determine charring of wood exposed to standard and natural fire that is based on a new numerical model named PyCiF. The new model couples an advanced 2D heat-mass model with a pyrolysis model. A new charring criterion based on a physical phenomenon is implemented in the PyCiF model to determine charring of wood. This presents the main advantage of the new PyCiF model in comparison to common modelling approaches, which require an empirical value of the charring temperature that is often called the char front temperature. The fact that the char front temperature is not an explicit value as assumed by the isotherm 300 °C is advantageously considered in the presented approach where an assumed empirical value of the char front temperature is not directly required to determine the thickness of char layer. The validation of the PyCiF model against experimental results showed great model accuracy, meaning that the model is appropriate for the evaluation of charring depths of timber elements exposed to the standard fire as well as the natural fires. Additionally, as shown in the case study, the presented approach also enables to determine the char front temperature for various natural fire exposures. This will be especially important for the upgrade of the new design methods for fire safety of timber elements exposed to natural fire given in the various design codes such as Eurocode 5.

Post-fire damage assessment and capacity based modeling of concrete exposed to elevated temperature

2019 ◽  
Vol 29 (5) ◽  
pp. 748-779 ◽  
Author(s):  
Daniel Paul Thanaraj ◽  
N Anand ◽  
G Prince Arulraj ◽  
Ehab Zalok
Keyword(s):  
Weight Loss ◽  
Elevated Temperature ◽  
Building Design ◽  
Strength Loss ◽  
Safety Measures ◽  
Civil Infrastructures ◽  
Standard Fire ◽  
Strain Behaviour ◽  
Fire Curve ◽  
Duration Of Heating

Fire represents one of the significant hazards encountered by civil infrastructures, and thus providing appropriate fire safety measures is a major requirement in a building design for ensuring the safety of the occupants. Minimizing fire-induced damage and collapse of structural systems are the primary objectives in the design of concrete structures. An experimental investigation has been carried out to examine the mechanical properties such as compressive, tensile and flexural strengths of concrete exposed to elevated temperature following standard fire curve as per ISO 834. Capacity-based standards have been formulated to predict the residual strength of various grades of concrete exposed to various duration of heating. Stress strain behaviour, elastic modulus, weight loss, spalling and thermal crack pattern of specimens were also investigated. Water–cement ratio and porosity of concrete were found to be the critical factors for strength loss of concrete. A relationship is established between weight loss and strength loss of concrete. Higher grades of concrete were found to have more weight and strength loss than those of lower grades.

scholarly journals Behavior of Fire Exposed Concrete-Filled Double Skin Steel Tubular (CFDST) Columns under Concentric Axial Loads

2015 ◽  
Vol 773-774 ◽  
pp. 938-942 ◽  
Author(s):  
S.S. Mohd Zuki ◽  
J. Jayaprakash ◽  
Shahiron Shahidan ◽  
Ong Chong Yong
Keyword(s):  
Exposure Time ◽  
Steel Tube ◽  
Fire Exposure ◽  
Axial Loads ◽  
Concrete Core ◽  
Failure Patterns ◽  
Standard Fire ◽  
Double Skin ◽  
Axial Behavior ◽  
Fire Curve

This paper presents the result of an experimental investigation of axial behavior of concrete-filled double skin steel tubular (CFDST) columns exposed to high temperature under the action of monotonically applied concentric axial loads. The columns were exposed to ASTM E-119 standard fire curve until 600°C and kept constant for two different exposure time (i.e., 60 and 90 minutes). Failure patterns and reduction in strength, ductility and stiffness of CFDST columns are reported. Factors influencing the strength, ductility and stiffness of CFDST columns during fire exposure, i.e., exposure time, temperature of concrete core and temperature of inner steel tube, are also discussed.

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