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35 records – page 1 of 4.

Analysis of Cross-Laminated Timber Charring Rates Upon Exposure to Non-Standard Heating Conditions

https://research.thinkwood.com/en/permalink/catalogue136
Year of Publication
2015
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Bartlett, Alastair
Hadden, Rory
Bisby, Luke
Law, Angus
Organization
Fire and Materials
Year of Publication
2015
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Charring Rate
Heat Release Rate
Fire Resistance
Conference
Fire and Materials 2015
Research Status
Complete
Notes
February 2-4, 2015, San Francisco, United States
Summary
The use of engineered timber products such as cross-laminated timber (CLT) is of increasing interest to architects and designers due to their desirable aesthetic, environmental, and structural properties. A key factor preventing widespread uptake of these materials is the uncertainty regarding their performance in fire. Currently, the predominant approach to quantifying the structural fire resistance of timber elements is the charring rate, which allows estimation of residual cross-section and hence strength. The charring rate is usually determined by testing timber specimens in a furnace by exposure to a ‘standard fire’. However, it is recognized that the resulting charring rates are not necessarily appropriate for non-standard fire exposures or for characterizing the structural response in a real timber building. The effect of heating rate on the charring rate of CLT samples is investigated. The charring rate resulting from three heating scenarios (constant, simulated ‘standard fire’ and quadratically increasing) was calculated using interpolation of in-depth temperature measurements during exposure to heating from a mobile array of radiant panels, or in a Fire Propagation Apparatus (FPA). Charring rate is shown to vary both spatially and temporally, and as a function of heating rate within the range 0.36–0.79 mm/min. The charring rate for tests carried out under simulated ‘standard fire’ exposures were shown to agree with the available literature, thus partially verifying the new testing approach; however under other heating scenarios the Eurocode charring rate guidance was found to be unconservative for some of the heat flux exposures in this study. A novel charring rate model is presented based on the experimental results. The potential implications of this study for structural fire resistance analysis and design of timber structures are discussed. The analysis demonstrates that heating rate, sample size and orientation, and test setup have significant effects on charring rate and the overall pyrolysis, and thus need to be further evaluated to further facilitate the use of structural timber in design.
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Behaviours of Larch Glued Laminated Timber Beams Exposed to Standard Fire Heating During the Cooling Phase Study on Fire Performance of Structural Glued Laminated Timber Beams Part 1

https://research.thinkwood.com/en/permalink/catalogue1112
Year of Publication
2015
Topic
Fire
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Kanjo, Hinjin
Hidemasa, Yusa
Horio, Takehito
Hirashima, Takeo
Takumi, Matsumoto
Saito, Kiyoshi
Publisher
J-STAGE
Year of Publication
2015
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Fire
Keywords
Larch
Load Bearing Capacity
Charring Rate
Cooling
Research Status
Complete
Series
Architectural Institute of Japan Structural System
Summary
Timber elements, which are different from other structural elements, have a characteristic problem in that the load bearing capacity decreases due to self-burning in the case of a fire, and this self-burning may continue after other fuel in the room has been exhausted. Therefore, the structural fire performance of timber elements should be clarified during not only the heating phase, but also the cooling phase. However, in examining the load bearing capacity of timber elements in a fire, few studies have considered the cooling phase. In the present paper, the fire performance of glued, laminated timber beams is discussed based on load-bearing fire tests that take the cooling phase into consideration.
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Chapter 6: Fire Damage of Wood Structures

https://research.thinkwood.com/en/permalink/catalogue897
Year of Publication
2012
Topic
Fire
Mechanical Properties
Material
Solid-sawn Heavy Timber
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Author
Kukay, Brian
White, Robert
Woeste, Frank
Publisher
International Code Council
Year of Publication
2012
Format
Book/Guide
Material
Solid-sawn Heavy Timber
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Topic
Fire
Mechanical Properties
Keywords
Bending Tests
Withdrawal Tests
Load Bearing Capacity
Charring
Reduced Cross Section Method
Research Status
Complete
Series
Inspection, Testing, and Monitoring of Buildings and Bridges
Summary
Depending on the severity, fire damage can compromise the structural integrity of wood structures such as buildings or residences. Fire damage of wood structures can incorporate several models that address (1) the type, cause, and spread of the fire, (2) the thermal gradients and fire-resistance ratings, and (3) the residual load capacity. The investigator should employ engineering judgment to identify those in-service members that are to be replaced, repaired, or can remain in-service as they are. Suchjudgment will likely be based on the visual inspection of damaged members, connections, and any protective membranes.
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Charring Behavior of Structural Timber Elements in Full-Scale Fire Tests of Three Story Timber School Buildings

https://research.thinkwood.com/en/permalink/catalogue1706
Year of Publication
2016
Topic
Fire
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Suzuki, Jun-ichi
Kaku, Chihiro
Naruse, Tomohiro
Kagiya, Koji
Noboru, Yasui
Itagaki, Naoyuki
Izumi, Jun-ichi
Seki, Mariko
Kaku, Teruhiko
Hasemi, Yuji
Year of Publication
2016
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Fire
Keywords
Charring Rate
Delamination
Full Scale
Fire Test
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4437-4446
Summary
The charring behavior of timber structural elements, such as the charring rate of timber elements and delamination of glue-laminated timber, affects the structural stability of timber buildings. The charring rate of timber elements varies depending on the severity of fire exposure. However, charring rates have been ordinarily investigated in fire tests under the standard fire exposure defined by ISO 834. It is important to accumulate and analyze data on the charring behavior of timber elements under actual fire exposure. The aim of this study was to clarify the charring behavior of glue-laminated timber structural elements exposed to actual fire in full-scale fire tests of three-story timber school buildings. Charred and uncharred areas of the timber structural elements were carefully observed and investigated after the fire tests. The charring rates of timber elements in full-scale fire tests ranged from 0.6 mm/min to 1.3mm/min. The charring rates were greater than the nominal charring rates reported in past studies because of preheating and severe fire exposure.
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Contribution of Cross Laminated Timber Panels to Room Fires

https://research.thinkwood.com/en/permalink/catalogue306
Year of Publication
2013
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems

Correct Temperature Measurements in Fire Exposed Wood

https://research.thinkwood.com/en/permalink/catalogue2025
Year of Publication
2018
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Fahrni, Reto
Schmid, Joachim
Klippel, Michael
Frangi, Andrea
Organization
ETH Zurich
Year of Publication
2018
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Temperature
Thermocouples
Charring
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
The performance of timber in fire is often assessed by measuring the temperature at different positions in the specimen. As timber is a low conductive material, it can be difficult to measure the correct temperature.Therefore, this paper shows how to correctly measure the temperature in timber members and how to describe temperature measurements of fire tests and experiments non-ambiguously.Typical temperature measurement setups used in tests and experiments were experimentally assessed under ISO/EN fire exposure and a constant incident radiant heat flux. By comparing the charring depth and the thermocouple readings(charring temperature 300°C) it was found that only the wire thermocouples inlaid parallel to the isotherms deliver correct temperature readings. For other temperature measurement setups, the underestimation was between 5 and 20 minutes.Due to the numerous factors influencing the measurement error, no correction factor could be defined.
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Cross-Laminated Timber Failure Modes for Fire Conditions

https://research.thinkwood.com/en/permalink/catalogue188
Year of Publication
2015
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Emberley, Richard
Torero, José
Year of Publication
2015
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Adhesives
Charring Rate
Delamination
Codes
Failure Modes
Conference
International Conference on Performance-based and Life-cycle Structural Engineering
Research Status
Complete
Notes
December 9-11, 2015, Brisbane, Australia
Summary
Tall timber building designs have utilized cross-laminated timber (CLT) significantly over the past decade due the sustainable nature of timber and the many advantages of using an engineered mass timber product. Several design methods have been established to account for the composite action between the orthogonally adhered timber plies. These methods assume perfect bonding of the adjacent plies by the adhesive. CLT designs methods for timber in fire have also been formulated. These methods rely on the relatively constant charring rate of timber to calculate a sacrificial layer to be added onto the cross-sectional area. While these methods focus on the timber failure mode of reduced cross section by charring, the failure mode of ply delamination is often overlooked and understudied. Due to the reduction of shear and normal strength in the adhesive, the perfect bond assumption can be questioned and a deeper look into the mechanics of CLT composite action and interfacial stress needs be conducted. This paper seeks to highlight the various design methods for CLT design and identify the failure mode of delamination not present in the current design codes.
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Evaluating Fire Performance of Nail-Laminated Timber: Influence of Gaps

https://research.thinkwood.com/en/permalink/catalogue2093
Year of Publication
2019
Topic
Fire
Material
NLT (Nail-Laminated Timber)
Application
Wood Building Systems
Author
Ranger, Lindsay
Dagenais, Christian
Organization
FPInnovations
Year of Publication
2019
Format
Report
Material
NLT (Nail-Laminated Timber)
Application
Wood Building Systems
Topic
Fire
Keywords
Charring
Gaps
Research Status
Complete
Summary
The objective of this work is to generate fire performance data for NLT assemblies to address gaps in technical knowledge. This project aims to study how the size of gaps between NLT boards might affect charring of an assembly and its overall fire performance. This research will support designers and builders in the use of mass timber assemblies in larger and taller buildings, by ensuring fire safe designs.
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Experimental and numerical analysis on fire behaviour of loaded cross-laminated timber panels

https://research.thinkwood.com/en/permalink/catalogue2869
Year of Publication
2020
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Wang, Yuexiang
Zhang, Jin
Mei, Fang
Liao Jiannan
Li, Weibin
Organization
Southeast University
Publisher
SAGE Journals
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Fire
Keywords
Charring Rate
Finite Element Model
Cohesive Elements
Fire Behavior
Research Status
Complete
Series
Advances in Structural Engineering
Summary
Cross-laminated timber is a relatively new engineered timber material that can be used in the design and construction of modern timber buildings. A key factor that raises concerns in the wide application of cross-laminated timber is the uncertainty of its fire performance. This article describes experimental and numerical investigations on the fire behaviour of loaded cross-laminated timber panels manufactured with Canadian hemlock. A total of 10 cross-laminated timber panels with different number and thickness of layers were tested under ambient and standard fire conditions to investigate the flexural capacity at ambient temperature, and temperature distribution, charring rate, fire resistance, mid-span deflection under fire exposure. Three-dimensional finite element model was developed using the Hashin criterion and cohesive elements to predict the failure of wood and adhesive, respectively. The thermal model implicitly considers the rapidly increased temperature of inner fresh timber after the protective charred layers have fallen off. The numerical model was validated with the results obtained from experimental tests and was found to have the ability to simulate the fire behaviour of loaded cross-laminated timber panels in reasonable accuracy.
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Experimental Assessment of the Fire Resistance Mechanisms of Timber–Steel Composites

https://research.thinkwood.com/en/permalink/catalogue2462
Year of Publication
2019
Topic
Fire
Mechanical Properties
Material
Steel-Timber Composite
Glulam (Glue-Laminated Timber)

35 records – page 1 of 4.