Auto-extinction of engineered timber: Application to compartment fires with exposed timber surfaces

Bartlett, Alastair I.; Hadden, Rory M.; Hidalgo, Juan P.; Santamaria, Simón; Wiesner, Felix; Bisby, Luke; Deeny, Susan; Lane, Barbara

doi:10.1016/j.firesaf.2017.03.050

Cited by 45 publications

(42 citation statements)

References 94 publications

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“…This is a significant difference between the two tests (approximately 50%), despite the energy provided by the natural gas being very similar between the two tests. This difference can be partially attributed to the variability of a natural material such as timber, as well as the stochastic nature of delamination, which can result in unpredictable and often very different behaviour from apparently identical test specimens …”

Section: Energy Analysessupporting

confidence: 88%

“…During the compartment fire experiments, it was observed that the CLT slabs continued to combust (through surface oxidation) for several hours after burnout of the compartment fuel load. This is consistent with findings from previous compartment fire experiments . This observation may have important implications for the fire resistance design of both encapsulated and unprotected mass timber elements as when testing combustible materials, they may continue burning without added fuel if no immediate active fire intervention is made.…”

Section: Discussionmentioning

confidence: 99%

“…This is consistent with findings from previous compartment fire experiments. 8,13 This observation may have important implications for the fire resistance design of both encapsulated and unprotected mass timber elements as when testing combustible materials, they may continue burning without added fuel if no immediate active fire intervention is made. Implicit in the traditional fire resistance ratings conventionally required for most building elements is the ability to withstand burnout of the fuel load within the compartment of origin.…”

Section: Discussionmentioning

confidence: 99%

“…This difference can be partially attributed to the variability of a natural material such as timber, as well as the stochastic nature of delamination, which can result in unpredictable and often very different behaviour from apparently identical test specimens. 8…”

Section: Timber Contributionmentioning

confidence: 99%

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Comparative energy analysis from fire resistance tests on combustible versus noncombustible slabs

Bartlett

McNamee²,

Robert

et al. 2019

Fire and Materials

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Summary Standard fire resistance tests have been used in the design of structural building elements for more than a century. Originally developed to provide comparative measures of the level of fire safety of noncombustible products and elements, the recent resurgence in engineered timber construction raises important questions regarding the suitability of standard fire resistance tests for combustible structural elements. Three standard fire resistance floor tests (5.9 m × 3.9 m in plan), one on a concrete slab and two on cross‐laminated timber (CLT) slabs, were undertaken to explore some of the relevant issues. The fuel consumption rate within the furnace was recorded during these tests, and the energy supplied from this was determined. An external fuel supply (from natural gas supplied to the furnace) equating to approximately 3 MW was recorded throughout the concrete test, whereas this was about 1.25 MW throughout the CLT tests. The total heat release rate was calculated using carbon dioxide generation calorimetry; this yielded values of approximately 1.75 MW during the CLT tests (ie, an additional energy contribution of approximately 0.5 MW from the timber). This demonstrates that considerably more energy input (by about 1.25 MW) was needed to heat the system when the test sample was noncombustible. A further series of six large‐scale compartment fire experiments (6 m × 4 m × 2.52 m) was undertaken to further explore comparative performance of combustible versus noncombustible construction when the external fuel load is kept constant and is governed by more realistic compartment fire dynamics. For a fuel‐controlled case, the peak temperatures in the compartment with an unprotected CLT ceiling were approximately 200°C higher than in the compartments with a concrete ceiling, whereas for a ventilation‐controlled case, the compartment with a CLT slab ceiling displayed a burning duration that increased by approximately 15 minutes. Potential implications for standard fire resistance testing of combustible specimens are discussed.

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Section: Energy Analysessupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Timber Contributionmentioning

confidence: 99%

See 2 more Smart Citations

Comparative energy analysis from fire resistance tests on combustible versus noncombustible slabs

Bartlett

McNamee²,

Robert

et al. 2019

Fire and Materials

Self Cite

View full text Add to dashboard Cite

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“…In other words, previous studies have largely focused on studying ignition to identify a single ignition criteria (temperature, mass loss rate, or heat flux). The extinction of wood has been treated in a similar manner to identify either a critical heat flux [11] or a critical mass loss rate [12].…”

Section: Introductionmentioning

confidence: 99%

Ignition and Burning of Fibreboard Exposed to Transient Irradiation

et al. 2020

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Natural materials like wood are increasingly used in the construction industry, making the understanding of their ignition and burning behaviour in fires crucial. The state of the art of wood flammability is based mostly on studies at constant heating. However, accidental fires are better represented by transient heating. Here, we study the piloted ignition and burning of medium density fibreboard (MDF) under transient irradiation. Experiments are conducted in a Fire Propagation Apparatus under parabolic heat flux pulses with peak irradiation ranging from 30 to 40 kW/m 2 and time-to-peak irradiation from 160 to 480 s. The experimental results reveal that the critical conditions for ignition of fibreboard vary over wide ranges: mass flux between 4.9 to 7.4 g/m 2-s, surface temperature between 276 to 298°C, and heat flux between 29 to 40 kW/m 2. Flameout conditions are studied as well, with observations of when it leads either to extinction or to smouldering combustion. We explored the experiments further with a one-dimensional pyrolysis model in Gpyro and show that predictions are accurate. Assuming a non-uniform density profile (a realistic assumption) improves the predictions in comparison to a uniform density profile by increasing the mass loss rate by 12%, decreasing the temperatures by 45%, and increasing the ignition time by 20 s. These results further support previous findings that a single critical condition for igntion or flameout established under constant irradiation does not hold under transient irradiation which indicates that ignition and extinction theories need improvements.

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Brandschutztechnische Grundlagenuntersuchungen und Empfehlungen für die Planung von mehrgeschossigen Gebäuden in Holzbauweise bis zur Hochhausgrenze

Zehfuß,

Engel,

Steeger

et al. 2024

Bauphysik Kalender 2024

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Auto-extinction of engineered timber: Application to compartment fires with exposed timber surfaces

Abstract: The following journal and conference papers have been published over the course of this thesis. Where these are based on part or whole of a chapter of this thesis, this is indicated.

Cited by 45 publications

References 94 publications

Comparative energy analysis from fire resistance tests on combustible versus noncombustible slabs

Comparative energy analysis from fire resistance tests on combustible versus noncombustible slabs

Ignition and Burning of Fibreboard Exposed to Transient Irradiation

Brandschutztechnische Grundlagenuntersuchungen und Empfehlungen für die Planung von mehrgeschossigen Gebäuden in Holzbauweise bis zur Hochhausgrenze

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