Skip header and navigation

Refine Results By

267 records – page 1 of 27.

Behavior of cross-laminated timber panels during and after an ISO-fire: An experimental analysis

https://research.thinkwood.com/en/permalink/catalogue3343
Year of Publication
2023
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Vairo, Maurizio
Silva, Valdir Pignatta
Icimoto, Felipe Hideyoshi
Organization
University of Sao Paulo
Publisher
Elsevier
Year of Publication
2023
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Charring
ISO-fire
Post-fire Stiffness Reduction
Cooling Phase
Finite Element Analysis
Research Status
Complete
Series
Results in Engineering
Summary
Cross-laminated timber has been used in buildings since the 1990s. In the last years, there has been a growing interest in the use of this technology, especially with the adoption of the product in increasingly taller buildings. Considering that the product is manufactured from a combustible material, wood, authorities that regulate the fire safety in buildings and the scientific community have carried out numerous research and fire tests, aiming to elaborate codes which contemplate the use of cross-laminated timber in tall buildings. This paper discusses the main results obtained from the fire resistance test of a cross-laminated timber slab carried out in the horizontal gas furnace (3.0 m × 4.0 m x 1.5 m) from the University of Sao Paulo. A vertical load of 3 kN/m2 was applied over the slab and the specimens were exposed to the standard fire curve for 30 min. In addition to the 30-min test, the research also evaluated the thermal behavior of the samples during the 24 h after the burners were turned off. Throughout the test, the slab maintained the integrity and the thermal insulation, and no falling-off of the charred layer was observed. However, the 24-h test indicated that it is mandatory to consider the loss of stiffness and strength of timber caused by the thermal wave observed during the decay phase.
Online Access
Free
Resource Link
Less detail

Large-scale compartment fires to develop a self-extinction design framework for mass timber—Part 1: Literature review and methodology

https://research.thinkwood.com/en/permalink/catalogue2911
Year of Publication
2022
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Xu, Hangyu
Pope, Ian
Gupta, Vinny
Cadena, Jaime
Carrascal, Jeronimo
Lange, David
McLaggan, Martyn
Mendez, Julian
Osorio, Andrés
Solarte, Angela
Soriguer, Diana
Torero, Jose
Wiesner, Felix
Zaben, Abdulrahman
Hidalgo, Juan
Organization
The University of Queesland
University of College London
The University of Edinburgh
Publisher
Elsevier
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Fire
Keywords
Performance-based Design
Compartment Fires
Heat Transfer
Pretection of Wood
Large-scale
Mass Timber
Research Status
Complete
Series
Fire Safety Journal
Summary
Fire safety remains a major challenge for engineered timber buildings. Their combustible nature challenges the design principles of compartmentation and structural integrity beyond burnout, which are inherent to the fire resistance framework. Therefore, self-extinction is critical for the fire-safe design of timber buildings. This paper is the first of a three-part series that seeks to establish the fundamental principles underpinning a design framework for self-extinction of engineered timber. The paper comprises: a literature review introducing the body of work developed at material and compartment scales; and the design of a large-scale testing methodology which isolates the fundamental phenomena to enable the development and validation of the required design framework. Research at the material scale has consolidated engineering principles to quantify self-extinction using external heat flux as a surrogate of the critical mass loss rate, and mass transfer or Damköhler numbers. At the compartment scale, further interdependent, complex phenomena influencing self-extinction occurrence have been demonstrated. Time-dependent phenomena include encapsulation failure, fall-off of charred lamellae and the burning of the movable fuel load, while thermal feedback is time-independent. The design of the testing methodology is described in reference to these fundamental phenomena.
Online Access
Free
Resource Link
Less detail

Large-Scale Enclosure Fire Experiments Adopting CLT Slabs with Different Types of Polyurethane Adhesives: Genesis and Preliminary Findings

https://research.thinkwood.com/en/permalink/catalogue2963
Year of Publication
2022
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Hopkin, Danny
Wegrzynski, Wojciech
Spearpoint, Michael
Fu, Ian
Krenn, Harald
Sleik, Tim
Gorska, Carmen
Stapf, Gordian
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Fire
Keywords
Adhesive
Bond-line Failure
Char Fall-off
Polyurethane
Auto-Extinction
Flame Spread
Research Status
Complete
Series
Fire
Summary
This paper provides understanding of the fire performance of exposed cross-laminated-timber (CLT) in large enclosures. An office-type configuration has been represented by a 3.75 by 7.6 by 2.4 m high enclosure constructed of non-combustible blockwork walls, with a large opening on one long face. Three experiments are described in which propane-fuelled burners created a line fire that impinged on different ceiling types. The first experiment had a non-combustible ceiling lining in which the burners were set to provide flames that extended approximately halfway along the underside of the ceiling. Two further experiments used exposed 160 mm thick (40-20-40-20-40 mm) loaded CLT panels with a standard polyurethane adhesive between lamella in one experiment and a modified polyurethane adhesive in the other. Measurements included radiative heat flux to the ceiling and the floor, temperatures within the depth of the CLT and the mass loss of the panels. Results show the initial peak rate of heat release with the exposed CLT was up to three times greater when compared with the non-combustible lining. As char formed, this stabilised at approximately one and a half times that of the non-combustible lining. Premature char fall-off (due to bond-line failure) was observed close to the burners in the CLT using standard polyurethane adhesive. However, both exposed CLT ceiling experiments underwent auto-extinction of flaming combustion once the burners were switched off.
Online Access
Free
Resource Link
Less detail

Smoke Hazards of Tall Timber Buildings with New Products

https://research.thinkwood.com/en/permalink/catalogue2964
Year of Publication
2022
Topic
Fire
Author
Cheng, Chi-Honn
Chow, Cheuk-Lun
Yue, Tsz-Kit
Ng, Yiu-Wah
Chow, Wan-Ki
Organization
City University of Hong Kong
The Hong Kong Polytechnic University
Editor
Formisano, Antonio
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Topic
Fire
Keywords
Tall Timber Buildings
Fire Hazards
Smoke Hazards
Public Concerns
New Timber Products
Research Status
Complete
Series
Encyclopedia
Summary
Timber buildings can now stand very tall using new products. As timber materials are expected to be easily ignitable, the fire hazard of timber is a concern. Charring of the timber surface would maintain structural stability, but would also be accompanied by smoke. Although treating timber products with fire retardants would delay the ignition time under low radiative heat flux, toxic combustion products and unburnt fuel would be emitted immediately upon burning. More smoke and higher toxic gas concentrations such as carbon monoxide would be given off upon burning some fire retardants under high flashover heat fluxes. Due to the fast upward movement of smoke under stack effect, spreading of toxic smoke in tall timber buildings would lead to a hazardous environment. Engineered timber consists of derivative timber products. New engineered timber products are manufactured with advanced technology and design, including cross-laminated-timber (CLT), laminated veneer lumber (LVL) and glue-laminated timber (Glulam). The fire behaviour of timber products has been studied for several decades. However, the smoke hazards of using new timber products in building construction should be monitored. The objective of this study is to inspire stakeholders in fire safety of timber buildings, inter alia smoke hazards, to use new timber products to build tall buildings.
Online Access
Free
Resource Link
Less detail

Thermophysical properties of balsa wood used as core of sandwich composite bridge decks exposed to external fire

https://research.thinkwood.com/en/permalink/catalogue3073
Year of Publication
2022
Topic
Fire
Application
Decking
Author
Vahedi, Niloufar
Tiago, Carlos
Vassilopoulos, Anastasios P.
Correia, João R.
Keller, Thomas
Organization
École Polytechnique Fédérale de Lausanne (EPFL)
Universidade de Lisboa
Publisher
Elsevier
Year of Publication
2022
Format
Journal Article
Application
Decking
Topic
Fire
Keywords
Balsa Wood
Effective Thermophysical Properties
Thermal Conductivity
Specific Heat Capacity
Coefficient of Thermal Expansion
Charring Temperature
Charring Rate
Research Status
Complete
Series
Construction and Building Materials
Summary
The load-bearing performance of sandwich bridge decks comprising a balsa core and fiber-reinforced polymer composite face sheets exposed to fire is a main concern regarding the application of these deck systems. In order to obtain the thermal responses of the balsa core exposed to fire, the temperature-dependent values of thermal conductivity and specific heat capacity are required. Furthermore, information about the char depth and charring rate and the temperature-dependent coefficient of thermal expansion is also needed for the subsequent thermomechanical modeling. In the current study, the effective thermal conductivity and specific heat capacity of balsa up to 850 °C were obtained from one-dimensional transient heat transfer models and experimental data using an inverse heat transfer analysis. The results showed that both properties depend significantly on the stages of combustion, direction of heat flow (in the tracheid or transverse direction) and density. Moreover, charring temperatures and rates were obtained, again as a function of direction and density. Finally, the coefficient of thermal expansion was measured in the transverse direction during evaporation and pyrolysis.
Online Access
Free
Resource Link
Less detail

A Circular Approach for the Fire Safety Design in Mass Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue3095
Year of Publication
2022
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Siri, Qvist
Organization
Delft University of Technology
Year of Publication
2022
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Mass Timber
Fire Safety Design
Circular Design
Fire Risk
Fire Resilience
Research Status
Complete
Summary
The building industry consumes a lot of material, which causes depletion of material stocks, toxic emissions, and waste. Circular building design can help to reduce this impact, by moving from a linear to a circular design approach. To reach a circular build environment, all disciplines should be involved, including fire safety design. However, there is a contradiction between the objectives of circular and fire safety design, either affecting the aim of protection of material sources, or protection against fire risk. Timber is a material that has high potential in contributing to a circular building industry, as it is renewable, recyclable and can store CO2. However, timber is combustible, which increases the risk of fire. Therefore, mass timber building design has traditionally been restricted by building regulations. To enhance mass timber building design research on timber buildings has increased, to allow understanding of the risks. However, yet general guidelines or understanding on the fire behaviour and risk in timber buildings is lacking. This is a problem for the fire safety design and the potentials of timber contributing to a circular building industry. Until now, there was no specific method available that quantifies this relation between material use and fire risk in mass timber buildings. This limits the possibility of fire safety design and mass timber design to contribute to a more circular building industry. By creating a method that allows comparison between the economic and environmental impact of material use and fire risk, a well-founded choice of building materials is easier to make. The design tool created in this research quantifies the impact on material use for fire safety measures relating to CLT, encapsulation and sprinkler availability and their effect on the fire risk in mass timber buildings. This way insight is provided between the balance of material use and fire risk. By the sum of the impact on material use and fire risk, the total “circular fire safety impact” value is calculated. This value represents the total economic and environmental impact of the design based on the choice of building materials. By changing the fire safety design, the most optimal design variant can be determined. This is the variant with the lowest total impact value. This way, a circular design approach is used to steer fire safety design in mass timber buildings towards a design solution that does not only provide sufficient safety for people, but also provides maximum economic and environmental safety from a material point of view.
Online Access
Free
Resource Link
Less detail

Calculating structural fire resistance of wood-frame assemblies

https://research.thinkwood.com/en/permalink/catalogue3200
Year of Publication
2022
Topic
Fire
Application
Floors
Walls
Author
Dagenais, Christian
Chorlton, Bronwyn
Chen, Zhiyong
Organization
FPInnovations
Year of Publication
2022
Application
Floors
Walls
Topic
Fire
Keywords
Small Cross Section
Light Wood Frame
Research Status
Complete
Series
InfoNote
Summary
This InfoNote summarizes the verification and validation that the current design requirements of Annex B of CSA O86 can also be applied to small framing members used in unprotected and protected lightweight wood-frame assemblies, e.g., walls and floors. With minor editorial changes, the scope of application of Annex B of CSA O86 could include all wood and wood-based products listed in CSA O86, regardless of their original and residual dimensions.
Online Access
Free
Resource Link
Less detail

Fire Severity Outcome Comparison of Apartment Buildings Constructed from Combustible and Non-Combustible Construction Materials

https://research.thinkwood.com/en/permalink/catalogue3202
Year of Publication
2022
Topic
Fire
Author
Zheng, Alex
Garis, Len
Pike, Ian
Organization
University of British Columbia
University of Fraser Valley
Publisher
Springer
Year of Publication
2022
Format
Journal Article
Topic
Fire
Keywords
Fire Safety
Combustible Materials
Non-combustible Materials
Apartment Fires
Wood-frame Structures
Research Status
Complete
Series
Fire Technology
Summary
Wood is commonly used in construction, but often perceived as being less safe than structures made from non-combustible materials. With the advancement of wood products and treatment, construction techniques, and protective systems, this may not be the case any longer. Using retrospective data from fire departments across Canada, this study aimed to determine whether the type of construction material (combustible or non-combustible) affected the fire severity outcome of a one to six storey apartment building fire, after accounting for protective systems (smoke alarms and sprinklers). The study found that, after adjusting for the presence of smoke alarms and sprinklers, structures constructed from non-combustible construction materials did not perform better in terms of injuries, requiring extinguishment by fire department, or the fire spreading beyond the room of origin. The presence of working smoke alarms and sprinklers played a central role in reducing the severity outcome of a fire. Smoke alarms and sprinklers both reduced the odds of extinguishment by the fire department and the fire spreading beyond the room of origin. Sprinklers also reduced the injury rate. Overall, this study highlighted the importance of protective systems in reducing fire severity outcomes.
Online Access
Free
Resource Link
Less detail

Modelling a CLT specimen protected with gypsum exposed to parametric fire curve heat flux

https://research.thinkwood.com/en/permalink/catalogue3216
Year of Publication
2022
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Osvaldova, Linda Makovicka
Magdolenova, Paulina
Markert, Frank
Zelinka, Samuel L.
Enoksen, Louise Frederikke
Klint, Malthe
Organization
University of Zilina
Technical University of Denmark
USDA Forest Service
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Gypsum Plaster Board
H-TRIS
Parametric Fire Curve
CFD Model
Fire Protection
Research Status
Complete
Series
Wood Research
Summary
This paper models bench-scale experiments using computational fluid dynamics (CFD). The experiments measured the temperature profiles of fire-protected cross laminated timber (CLT) specimens exposed to parametric fire curve. The bench-scale experiment specimen is 250 x 250 mm and consists of a CLT panel 100 mm with three layers of gypsum plasterboard 15.5 mm as thermal and fire insulation. The specimens were exposed to a heat flux generated by a heat-transfer rate inducing system (H-TRIS) device. Two numerical models were created in order to copy the experiment conditions, one by using basic modelling techniques and one using advanced method. Comparing the layer temperature values of the experiment and basic model, a great difference was found. The difference between experimental and model temperatures increases the closer the analysed layer is to the heat source. The results show a good agreement between the model and the experiments, especially for the advanced numerical model.
Online Access
Free
Resource Link
Less detail

European Yield Model Exponential Decay Constant Modification for Glulam after Fire Exposure

https://research.thinkwood.com/en/permalink/catalogue3294
Year of Publication
2022
Topic
Fire
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Shakimon, Mohd Nizam
Hassan, Rohana
Malek, Nor Jihan Abd
Zainal, Azman
Awaludin, Ali
Hamid, Nor Hayati Abdul
Lum, Wei Chen
Salit, Mohd Sapuan
Organization
Infrastructure University Kuala Lumpur (IUKL)
University Teknologi MARA
Gadjah Mada University
Universiti Putra Malaysia (UPM)
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Fire
Keywords
Tropical Timber
Glulam Beam
Decay Constant
Finite Element Model
Post-fire
Numerical Model
EYM Modification
Research Status
Complete
Series
Forests
Summary
Many real-scale fire tests have been performed on timber connections to analyze the mechanical behavior of timber connections in previous years. However, little research focused on the bending performance of glued laminated (glulam) timber beam bolted connections after fire exposure. In this paper, the three-dimensional numerical model of the glulam timber beam bolted connections was developed and validated by experimental results. The model can simulate temperature evolution in the connections and their mechanical behavior. In the real-scale test, three (3) samples were prepared for a four-point bending test at normal temperature, while another three (3) samples were tested after exposure to a 30-min standard fire and cooled down to normal temperature. The results show the reduction of the load-carrying capacity before and after exposure to the standard fire by 23.9 kN (71.8%), 8.3 kN (26.1%), and 20.2 kN (47.6%) for bolt diameters of 12 mm, 16 mm, and 20 mm, respectively. The numerical model aims to conduct a parametric study and propose the modification of the exponential decay constant, k, for tropical glulam timber to predict the load-carrying capacity of the glulam timber beam bolted connections after exposure to standard fire.
Online Access
Free
Resource Link
Less detail

267 records – page 1 of 27.