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45 records – page 1 of 5.

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
Country of Publication
United States
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Charring Rate
Heat Release Rate
Fire Resistance
Language
English
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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Auto-Extinction of Engineered Timber as a Design Methodology

https://research.thinkwood.com/en/permalink/catalogue1676
Year of Publication
2016
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Bartlett, Alastair
Hadden, Rory
Bisby, Luke
Lane, Barbara
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Extinction
Fire Propagation Apparatus
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3934-3941
Summary
Engineered timber products such as cross-laminated timber (CLT) are gaining popularity with designers due to attractive aesthetic, sustainability, and constructability credentials. The fire behaviour of such materials is a key requirement for buildings formed predominantly of exposed, structural timber elements. Whilst design guidance focuses on the residual structural capacity of timber elements exposed to a ‘standard fire’, the fundamental characteristics of CLT’s performance in fire, such as ignition, flame spread, delamination, and extinction are not currently considered. This paper focuses on the issues relating to increased fuel load due to a combustible building material itself. Whilst an increasingly common protection solution to this conundrum is to fully encapsulate the timber elements, there is limited supporting test data on this approach. Through understanding these concepts from a fundamental, scientific perspective, the behaviour can be properly understood, and, rather than limiting design, can be incorporated into design to satisfy suitable performance criteria. In this paper therefore, the concept of auto-extinction – a phenomenon by which a timber sample will cease flaming when the net heat flux to the sample drops below a critical value – is explored experimentally and related to firepoint theory. A series of c.100 small scale tests in a Fire Propagation Apparatus (FPA) have been carried out to quantify the conditions under which flaming extinction occurs. Critical mass loss rate at extinction is shown to occur at a mass flux of 3.5g/m2s or a temperature gradient of 28K/mm at the charline. External heat flux and airflow were not found to affect the critical mass loss rate at the range tested. This approach is then compared with a compartment fire with multiple exposed timber surfaces. With further testing and refinement, this method may be applied in design, enabling architects’ visions of exposed, structural timber to be safely realised.
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BIM-Based Code Compliance Checking for Fire Safety in Timber Buildings: A Comparison of Existing Tools

https://research.thinkwood.com/en/permalink/catalogue2110
Year of Publication
2019
Topic
Design and Systems
Fire
Application
Wood Building Systems

Challenge to Two-Hours Fire-Resistive Glued Laminated Timber Made of Japanese Cedar

https://research.thinkwood.com/en/permalink/catalogue1711
Year of Publication
2016
Topic
Fire
Material
Glulam (Glue-Laminated Timber)
Author
Hattori, Nobuaki
Ando, Keisuke
Harada, Toshiro
Kamikawa, Daisuke
Miyabayashi, Masayuki
Nishimura, Kouta
Kakae, Norichika
Miyamoto, Keiichi
Nishide, Naoki
Hebiishi, Takahiro
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Fire
Keywords
Japanese Cedar
Fire Test
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4487-4494
Summary
We developed a one-hour fire-proof glulam made of Japanese cedar and got the authorization as abuilding material from the Minister of Land, Infrastructure and Transportation. We also succeeded to give one-hour fire performance to cross laminated timber (CLT) using the same concept. The both structures consist of three parts which are load-bearing part, fire-die-out part and surface part. Therefore, we challenged two-hours fire-resistive glulam using the same concept. We used not only drill but also CO2 laser as an incising for lamina of fire-die-out parts and impregnated the fire retardant evenly for diffusion. The main reason to use drill is that the handling of CO2 laser is not so easy for glulam manufacturer. Comparisons of fire-performance between fire-die-out parts whose lamina were incised by drill and CO2 laser, and finger jointed load-bearing part made of Japanese cedar and larch were also achieved using the same glulam whose fire-die-out part is 90 mm in total thickness. The fire test was achieved in a furnace in accordance with a standard heating curve by ISO 834-1. Though this glulam failed two-hours fire performance by a little char and discoloration, we could know the difference in incising method and density of load-bearing part.
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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
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Fire
Keywords
Charring Rate
Delamination
Full Scale
Fire Test
Language
English
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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The Charring Rate of Glulam Beams of Brazilian Wood Species

https://research.thinkwood.com/en/permalink/catalogue1771
Year of Publication
2016
Topic
Fire
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Martins, Gisele
Munaiar Neto, Jorge
Calil Junior, Carlito
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Fire
Keywords
Charring Rate
Brazil
Density
Fire Test
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 5302-5309
Summary
The combustibility of timber is one of the factors that restrict the use of structural elements of wood in buildings in Brazil. This paper describes an experimental investigation of the charring rate of wood species. The charring rate is one of the key parameters for the design of load bearing timber structures. The purpose of this study is...
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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)

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
Country of Publication
Australia
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Adhesives
Charring Rate
Delamination
Codes
Failure Modes
Language
English
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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Delamination Occurrence in Engineered Mass Timber Products at Elevated Temperatures

https://research.thinkwood.com/en/permalink/catalogue1770
Year of Publication
2016
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Emberley, Richard
Yu, Zeyu
Fernando, Dilum
Torero, José
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Thermal Penetration Depths
Heat Flux
Shear Tests
Temperature
Delamination
Failure Modes
Charring
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 5294-5301
Summary
An experimental study was conducted to elucidate the effects of thermal penetration on delamination and the potential changes in failure mode of CLT. The first test series studied thermal penetration depths at various heat fluxes. The second test series consisted of single lap shear tests at homogeneous elevated temperatures followed by a...
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Design of Post-Tensioned Timber Beams for Fire Resistance

https://research.thinkwood.com/en/permalink/catalogue4
Year of Publication
2012
Topic
Design and Systems
Fire
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Author
Buchanan, Andrew
Abu, Anthony
Carradine, David
Moss, Peter
Spellman, Phillip
Year of Publication
2012
Country of Publication
Switzerland
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Topic
Design and Systems
Fire
Keywords
Full Scale
Furnace Tests
Post-Tensioned
Box Beams
Vertical Loads
Failure
Language
English
Conference
International Conference on Structures in Fire
Research Status
Complete
Notes
June 6-8, 2012, Zurich, Switzerland
Summary
This paper describes a series of three full-scale furnace tests on post-tensioned LVL box beams loaded with vertical loads, and presents a proposed fire design method for post-tensioned timber members. The design method is adapted from the calculation methods given in Eurocode 5 and NZS:3603 which includes the effects of changing geometry and several failure mechanisms specific to posttensioned timber. The design procedures include an estimation of the heating of the tendons within the timber cavities, and relaxation of post-tensioning forces. Additionally, comparisons of the designs and assumptions used in the proposed fire design method and the results of the full-scale furnace tests are made. The experimental investigation and development of a design method have shown several areas which need to be addressed. It is important to calculate shear stresses in the timber section, as shear is much more likely to govern compared to solid timber. The investigation has shown that whilst tensile failures are less likely to govern the fire design of post-tensioned timber members, due to the axial compression of the post-tensioning, tensile stresses must still be calculated due to the changing centroid of the members as the fire progresses. Research has also highlighted the importance of monitoring additional deflections and moments caused by the high level of axial loads.
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45 records – page 1 of 5.