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36 records – page 1 of 4.

Ability of Finger-Jointed Lumber to Maintain Load at Elevated Temperatures

https://research.thinkwood.com/en/permalink/catalogue1832
Year of Publication
2018
Topic
Fire
Material
Other Materials
Author
Rammer, Douglas
Zelinka, Samuel
Hasburgh, Laura
Craft, Steven
Publisher
Forest Products Laboratory
Year of Publication
2018
Format
Journal Article
Material
Other Materials
Topic
Fire
Keywords
Small Scale
Full Scale
Bending Test
Melamine Formaldehyde
Phenol-Resorcinol Formaldehyde
Creep
Polyurethane
Polyvinyl Acetate
Temperature
Durability
Research Status
Complete
Series
Wood and Fiber Science. 50(1): 44-54.
Summary
This article presents a test method that was developed to screen adhesive formulations for finger-jointed lumber. The goal was to develop a small-scale test that could be used to predict whether an adhesive would pass a full-scale ASTM E119 wall assembly test. The method involved loading a 38-mm square finger-jointed sample in a four-point bending test inside of an oven with a target sample temperature of 204°C. The deformation (creep) was examined as a function of time. It was found that samples fingerjointed with melamine formaldehyde and phenol resorcinol formaldehyde adhesives had the same creep behavior as solid wood. One-component polyurethane and polyvinyl acetate adhesives could not maintain the load at the target temperature measured middepth of the sample, and several different types of creep behavior were observed before failure. This method showed that the creep performance of the onecomponent adhesives may be quite different than the performance from short-term load deformation curves collected at high temperatures. The importance of creep performance of adhesives in the fire resistance of engineered wood is discussed.
Online Access
Free
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Assessment of Structural Performance of Accoya® Wood for Glulam Fabrication

https://research.thinkwood.com/en/permalink/catalogue1199
Year of Publication
2012
Topic
Mechanical Properties
Serviceability
Material
Glulam (Glue-Laminated Timber)

Circular Economy & the Built Environment Sector in Canada

https://research.thinkwood.com/en/permalink/catalogue2805
Year of Publication
2021
Topic
Environmental Impact
Design and Systems
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
NLT (Nail-Laminated Timber)
Other Materials
Application
Wood Building Systems
Hybrid Building Systems
Organization
Delphi Group
SCIUS Advisory
Year of Publication
2021
Format
Report
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
NLT (Nail-Laminated Timber)
Other Materials
Application
Wood Building Systems
Hybrid Building Systems
Topic
Environmental Impact
Design and Systems
Keywords
Circular Economy
Greenhouse gas emissions
Waste
Demolition
Design for Disassembly and Adaptibility
Design for Durability
Deconstruction
Material Recovery
Reverse Logistics
Research Status
Complete
Summary
This study on Circular Economy & the Built Environment Sector in Canada was carried out by The Delphi Group in collaboration with Scius Advisory and completed in March 2021 on behalf of Forestry Innovation Investment Ltd. (FII) in British Columbia and Natural Resources Canada (NRCan) as the co-sponsors for the research. The work identifies a broad range of current efforts across Canada and undertakes a deeper dive on design for disassembly and adaptability (DfD/A) best practices, including an analysis of the ISO Standard 20887:2020 (i.e., design for disassembly and adaptability) in line with current Canadian industry practice and market readiness.
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Free
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Comparison of Different Assembling Techniques Regarding Cost, Durability, and Ecology: A Survey of Multi-Layer Wooden Panel Assembly Load-Bearing Construction Elements

https://research.thinkwood.com/en/permalink/catalogue62
Year of Publication
2015
Topic
Cost
Design and Systems
Material
CLT (Cross-Laminated Timber)
Author
Buck, Dietrich
Wang, Alice
Hagman, Olle
Gustafsson, Anders
Publisher
North Carolina State University
Year of Publication
2015
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Cost
Design and Systems
Keywords
Durability
Assembling Techniques
Research Status
Complete
Series
BioResources
Summary
Wood is a pure, sustainable, renewable material. The increasing use of wood for construction can improve its sustainability. There are various techniques to assemble multi-layer wooden panels into prefabricated, load-bearing construction elements. However, comparative market and economy studies are still scarce. In this study, the following assembling techniques were compared: laminating, nailing, stapling, screwing, stress laminating, doweling, dovetailing, and wood welding. The production costs, durability, and ecological considerations were presented. This study was based on reviews of published works and information gathered from 27 leading wood product manufacturing companies in six European countries. The study shows that the various techniques of assembling multi-layer wooden construction panel elements are very different. Cross laminated timber (CLT) exhibited the best results in terms of cost and durability. With regard to ecological concerns, dovetailing is the best. Taking into account both durability and ecological considerations, wooden screw-doweling is the best. These alternatives give manufacturers some freedom of choice regarding the visibility of surfaces and the efficient use of lower-quality timber. CLT is the most cost-effective, is not patented, and is a well-established option on the market today.
Online Access
Free
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Cross-Laminated Timber—North American CLT vs. Imported Product

https://research.thinkwood.com/en/permalink/catalogue3088
Year of Publication
2020
Topic
General Information
Material
CLT (Cross-Laminated Timber)
Organization
APA
Year of Publication
2020
Format
Document
Material
CLT (Cross-Laminated Timber)
Topic
General Information
Keywords
Design Property Compatibility
Adhesive Heat Durability
Moisture Durability
Fire Performance
Research Status
Complete
Summary
Cross-laminated timber (CLT) manufactured in North America must meet stringent product standards and be certified to the ANSI/APA PRG 320 Standard for Performance-Rated Cross-Laminated Timber. This publication from APA - The Engineered Wood Association explains the key characteristics that are evaluated in certification process. When comparing North Amarican CLT to products manufactured elsewhere, it is important to recognize that products manufactured outside of North Amarica may not meet the performance expections defined in the ANSI standard.
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Free
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Development of a Slab-on-Girder Wood-Concrete Composite Highway Bridge

https://research.thinkwood.com/en/permalink/catalogue1421
Year of Publication
2012
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Author
Lehan, Andrew
Organization
University of Toronto
Year of Publication
2012
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Topic
Design and Systems
Keywords
Ultra-High-Performance Fibre-Reinforced Concrete
Girder
Post-Tensioning
Prefabrication
Durability
Span-to-Depth Ratio
Research Status
Complete
Summary
This thesis examines the development of a superstructure for a slab-on-girder wood-concrete composite highway bridge. Wood-concrete composite bridges have existed since the 1930's. Historically, they have been limited to spans of less than 10 m. Renewed research interest over the past two decades has shown great potential for longer span capabilities. Through composite action and suitable detailing, improvements in strength, stiffness, and durability can be achieved versus conventional wood bridges. The bridge makes use of a slender ultra-high performance fibre-reinforced concrete (UHPFRC) deck made partially-composite in longitudinal bending with glued-laminated wood girders. Longitudinal external unbonded post-tensioning is utilized to increase span capabilities. Prefabrication using double-T modules minimizes the need for cast-in-place concrete on-site. Durability is realized through the highly impermeable deck slab that protects the girders from moisture. Results show that the system can span up to 30 m while achieving span-to-depth ratios equivalent or better than competing slab-on-girder bridges.
Online Access
Free
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Development Of CLT Products with Improved Fire Performance

https://research.thinkwood.com/en/permalink/catalogue2598
Year of Publication
2020
Topic
Design and Systems
Fire
Material
CLT (Cross-Laminated Timber)
Author
He, Guangbo
Feng, Martin
Roussiere, Fabrice
Organization
FPInnovations
Year of Publication
2020
Format
Report
Material
CLT (Cross-Laminated Timber)
Topic
Design and Systems
Fire
Keywords
Fire Resistance
Adhesives
Bond Durability
Bonding
Treated Wood
Research Status
Complete
Summary
The fire resistance of cross-laminated timber (CLT) could be improved by treating the lamina with fire retardants. The major issues with this technology are the reduced bondability of the treated lamina with commercial adhesives. This study assessed several surface preparation methods that could improve the bondability and bond durability of fire-retardant treated wood with two commercial adhesives. Four surface preparation methods, including moisture/heat/pressure, surface planing, surface chemical treatment, and surface plasma treatment were assessed for their impact on the bondability and bond durability of lodgepole pine lamina. The block shear test results indicated that all surface preparation methods were somewhat effective in improving bond performance of fire-retardant treated wood compared to the untreated control wood samples, depending on the types of fire retardants and wood adhesives applied in the treatment process and bonding process. The selection of surface preparation, fire retardant, and wood adhesive should be considered interactively to obtain the best bond properties and fire performance. It may be possible to effectively bond the treated lamina with PUR adhesive without any additional surface preparation for the fire retardant used in the treatment at FPInnovations.
Online Access
Free
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Development of Design Values for Hem-Fir Cross-Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue116
Year of Publication
2015
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Pirvu, Ciprian
Organization
FPInnovations
Year of Publication
2015
Format
Report
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Hem-Fir
Visually graded
Machine Stress Rated
Durability
Bondlines
Canada
US
Research Status
Complete
Summary
The North American product standard for performance-rated cross-laminated timber (CLT), ANSI/APA PRG 320, was published in 2012. The standard recognizes the use of all major Canadian and US softwood species groups for CLT manufacturing and provides design properties for specific CLT layups with visually graded and E-rated/MSR laminations. While design properties for CLT layups with Spruce-Pine-Fir and Douglas fir-Larch laminations are specified in the current standard, no design properties are indicated for CLT layups with Hem-Fir laminations. Design properties for two proposed CLT grades manufactured with Hem-Fir lumber were developed. These include a CLT layup with visually graded laminations and another layup with E-rated/MSR laminations. Design properties for these two CLT layups were calculated separately for use in Canada and the US. Supporting information for the addition of design properties for Hem-Fir grades to the CLT product standard was generated. Recommended amendments to the CLT product standard include durability and wood failure requirements of bondlines, and design properties for Hem-Fir layups.
Online Access
Free
Resource Link
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Development of Preservative-treated Southern Pine Cross-laminated Timber

https://research.thinkwood.com/en/permalink/catalogue2566
Topic
Moisture
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Industrial Application
Organization
Mississippi State University
Material
CLT (Cross-Laminated Timber)
Application
Industrial Application
Topic
Moisture
Mechanical Properties
Keywords
Industrial Mats
Preservative Treatment
Weathering
Durability
Research Status
In Progress
Notes
Project contact is Hyungsuk Lim at Mississippi State University
Summary
This project aims to develop the preservative-treatment procedures for industrial cross-laminated timber (CLT) mats composed of southern yellow pine (SYP) lumber. The feasibility of pre- and post-treating CLT panels with an environment-friendly preservative system for ground-contact applications at an industrial scale will be evaluated from adhesion, mechanical, and durability performance aspects. As for the pre-treatment method, CLT panels will be consolidated with preservative-treated lumber adopting industrial CLT manufacturing parameters, including glue-type and clamping pressure. Alternatively, conventional CLT panels will be pressure treated with the same preservative system and dried afterward. As one of the primary focuses of the research, drying schedules which would not damage wood or adhesive layers will be determined. Also, penetration and retention of the preservatives throughout the post-treated panels will be analyzed. Adhesion and mechanical performance of the treated panels will be evaluated according to industry-accepted standards. Durability performance of the treated panels will be examined through laboratory weathering and on-site field tests.
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Durability of Mass Timber Structures: a Review of the Biological Risks

https://research.thinkwood.com/en/permalink/catalogue1838
Year of Publication
2018
Topic
Environmental Impact
Serviceability
Material
CLT (Cross-Laminated Timber)
Author
Wang, Jasmine
Stirling, Rod
Morris, Paul
Taylor, Adam
Lloyd, Jeff
Kirker, Grant
Lebow, Stan
Mankowski, Mark
Organization
Forest Products Laboratory
Year of Publication
2018
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Environmental Impact
Serviceability
Keywords
High-Rise
Durability
Biodegradation
Wood Protection
Research Status
Complete
Series
Wood and Fiber Science
Summary
Mass timber structures have the potential to change wooden construction on a global scale. Numerous mass timber high-rise buildings are in planning, under development or already built and their performance will alter how architects and engineers view wood as a material. To date, the discussion of material durability and biodegradation in these structures has been limited. While all materials can be degraded by wetting, the potential for biodegradation of wood in a mass timber building requires special consideration. Identifying and eliminating the conditions that might lead to this degradation will be critical for ensuring proper performance of wood in these structures. This article reviews and contrasts potential sources of biodegradation that exist for traditional wood construction with those in mass timber construction and identifies methods for limiting the degradation risk. Finally, future research needs are outlined.
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Free
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36 records – page 1 of 4.