A numerical approach for modeling the fire induced restraint effects in reinforced concrete beams

Dwaikat, Mahmud; Kodur, Venkatesh

doi:10.1016/j.firesaf.2007.08.003

Cited by 96 publications

(70 citation statements)

References 9 publications

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“…Thus, various models have been proposed to approximate this behavior, including finite element approaches (Bratina et al 2005;Dwaikat and Kodur 2008;Wang et al 2011) as well as semi-empirical approaches (Wickstrom 1986;Hertz 1981).…”

Section: Resistance Modelmentioning

confidence: 99%

Reliability Analysis of RC Beams Exposed to Fire

Eamon

Jensen

2013

J. Struct. Eng.

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A procedure for conducting reliability analysis of reinforced concrete beams subjected to a fire load is presented. This involves identifying relevant load combinations, specifying critical load and resistance random variables, and establishing a high-temperature performance model for beam capacity. Based on the procedure, an initial reliability analysis is conducted using currently available data. Significant load random variables are taken to be dead load, sustained live load, and fire temperature. Resistance is in terms of moment capacity, with random variables taken as steel yield strength, concrete compressive strength, placement of reinforcement, beam width, and thermal diffusivity. A semi-empirical model is used to estimate beam moment capacity as a function of fire exposure time, which is calibrated to experimental data available in the literature.The effect of various beam parameters were considered, including cover, beam width, aggregate type, compressive strength, dead to live load ratio, reinforcement ratio, support conditions, mean fire temperature, and other parameters. Using the suggested procedure, reliability was estimated from zero to four hours of fire exposure using Monte Carlo simulation. It was found that reliability decreased nonlinearly as a function of time, while the most significant parameters were concrete cover; span/depth ratio when axial restraints are present, mean fire temperature; and support conditions.

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Section: Resistance Modelmentioning

confidence: 99%

Reliability Analysis of RC Beams Exposed to Fire

Eamon

Jensen

2013

J. Struct. Eng.

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“…More details on the model extension are given the following section. Full details of the numerical procedure, including the derivation of appropriate equations, are presented elsewhere [21,30].…”

Section: Generalmentioning

confidence: 99%

“…The axial restraint stiffness (k) is assumed to be 50 kN/ mm for the axially restrained beams. This value of the axial restraint stiffness is selected in such a way that it represents restraint conditions commonly encountered in practice [30]. Each beam is analyzed under four fire scenarios including two standard (ASTM E119 and ASTM E1529) and two design fire exposures.…”

Section: Analysis Detailsmentioning

confidence: 99%

Fire Induced Spalling in High Strength Concrete Beams

Dwaikat

Kodur

2009

Fire Technol

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A macroscopic finite element model is extended to account for fire induced spalling in high strength concrete (HSC) beams. The model is based on the principles of mechanics and thermodynamics and utilizes pore pressure calculations to predict fire induced spalling in concrete. For validating the model, spalling measurements were made by conducting fire resistance experiments on four normal strength and high strength concrete beams. Spalling predictions from the model are compared with the measured values of spalling at various stages of fire exposure. The validated model is applied to investigate the influence of fire scenario, concrete strength (permeability) and axial restraint on the fire induced spalling and fire response of RC beams. Results from the analysis show that fire scenario, and concrete permeability largely influence the extent of fire induced spalling in concrete beams. Further, it is also shown that the extent of spalling has significant influence on the fire resistance of RC beams.

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“…The model also gives the designers a powerful tool to identify the upper and lower safety boundaries of the reinforced concrete slabs in fire. This approach was also adopted in previous research [14,15] for modelling the impact of concrete spalling on the fire resistance of reinforced concrete beam-column frames.…”

Section: Introductionmentioning

confidence: 99%

The behaviour of reinforced concrete slabs in fire

Huang

2010

Fire Safety Journal

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In this paper a robust model is presented based on the previous layer procedure developed by the author to also take into account the effects of concrete spalling on the behaviour of concrete slabs under fire conditions. In this study, a detailed analysis of a uniformly loaded reinforced concrete slab subject to different degrees of concrete spalling under a standard fire regime is first carried out. Further, a series of analysis of floor slabs with different degrees of concrete spalling is also performed on a generic reinforced concrete building. A total of 16 cases have been analysed using different degrees of spalling on the slabs, with different extents and positions of localised fire compartments. It is clear that adjacent cool structures provide considerable thermal restraint to the floor slabs within the fire compartment. And it is evident that the compressive membrane force within the slabs is a major player in reducing the impact of concrete spalling on the structural behaviour of floor slabs in fire.

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A numerical approach for modeling the fire induced restraint effects in reinforced concrete beams

Cited by 96 publications

References 9 publications

Reliability Analysis of RC Beams Exposed to Fire

Reliability Analysis of RC Beams Exposed to Fire

Fire Induced Spalling in High Strength Concrete Beams

The behaviour of reinforced concrete slabs in fire

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