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32 records – page 1 of 4.

The Analysis of Bending Stiffness and Strength of Glue Laminated Nigerian Timber

https://research.thinkwood.com/en/permalink/catalogue2579
Year of Publication
2020
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Okafor, Kingsley
Ezeagu, Celestine
Publisher
Europa Publishing
Year of Publication
2020
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Keywords
Flexural Strength
Polyurethane
PUR
Adhesive
Timber
Research Status
Complete
Series
European Journal of Engineering Research & Science
Summary
An analysis into the flexural strength of solid and laminated timber specimens under working conditions was conducted. Five hardwoods and five softwoods were investigated, namely: Mansonia, Mahogany, Orji, Ukpi, Ufi mmanu, White Afara, Owen, Melina, Akpu and Ubia. The dimensions of the wood specimens are 100mm×50mm×20mm. The wood samples were tested for flexural strength using a Universal Testing Tensile Machine. The results obtained shows that Owen has the highest ultimate wood strength of 46.806N/mm² for the softwood glulam. Ukpi has the highest wood strength of 73.375N/mm² for the hardwood glulam, and highest MOE at 2412.93N/mm². Akpu recorded the weakest sample with bending strength values for glulam at 11.929 N/mm². Comparisons of strength were made to their respective solid timbers. Failure modes were analyzed. The study therefore demonstrates that the timber species used can be engineered to load bearing glulam structural elements using polyurethane adhesive glue without severe loss of strength.
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Analysis of Glue Line and Correlations Between Anatomical Characteristics of Eucalyptus grandis × Eucalyptus urophylla Glued-Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue2435
Year of Publication
2019
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems

Apparent Sound Insulation in Mass Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue2616
Year of Publication
2020
Topic
Acoustics and Vibration
Design and Systems
Material
CLT (Cross-Laminated Timber)
NLT (Nail-Laminated Timber)
DLT (Dowel Laminated Timber)
Application
Floors
Walls
Author
Mahn, Jeffrey
Quirt, David
Mueller-Trapet, Markus
Hoeller, Christoph
Organization
National Research Council of Canada. Construction
Publisher
National Research Council of Canada. Construction
Year of Publication
2020
Format
Report
Material
CLT (Cross-Laminated Timber)
NLT (Nail-Laminated Timber)
DLT (Dowel Laminated Timber)
Application
Floors
Walls
Topic
Acoustics and Vibration
Design and Systems
Keywords
Airborne Sound Transmission
Apparent Sound Transmission Class
Sound Transmission
Adhesive
Research Status
Complete
Summary
This Report presents the results from experimental studies of the airborne sound transmission of mass timber assemblies, together with an explanation of the calculation procedures to predict the apparent sound transmission class (ASTC) rating between adjacent spaces in a building constructed of mass timber assemblies. The experimental data which is the foundation for this Report includes the laboratory measured sound transmission loss of wall and floor assemblies constructed of Cross Laminated Timber (CLT), Nail-Laminated Timber (NLT) and Dowel-Laminated Timber (DLT), and the laboratory measured vibration reduction index between assemblies of junctions between CLT assemblies. The presentation of the measured data is combined with the presentation of the appropriate calculation procedures to determine the ASTC rating in buildings comprised of such assemblies along with numerous worked examples. Several types of CLT constructions are commercially available in Canada, but this study focused on CLT assemblies with an adhesive applied between the faces of the timber elements in adjacent layers, but no adhesive bonding between the adjacent timber elements within a given layer. These CLT assemblies could be called “Face-Laminated CLT Assemblies” but are simply referred to as CLT assemblies in this Report. Another form of CLT assemblies does have adhesive applied between the faces of the timber elements in adjacent layers as well as adhesive to bond the adjacent timber elements within a given layer. These assemblies are referred to as “Fully-Bonded CLT Assemblies” in this Report. Because fully-bonded CLT assemblies have different properties than face-laminated CLT assemblies, the sound transmission data and predictions in this Report do not apply to fully-bonded CLT assemblies.
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Application of Modern Wood Product Glulam in Timber Frame with Tenon- Mortise Joints and its Structural Behavior

https://research.thinkwood.com/en/permalink/catalogue2469
Year of Publication
2019
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)

Assessing the Adhesive Performance in CLT Exposed to Fire

https://research.thinkwood.com/en/permalink/catalogue1945
Year of Publication
2018
Topic
Connections
Fire
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Author
Klippel, Michael
Schmid, Joachim
Fahrni, Reto
Frangi, Andrea
Organization
ETH Zurich
Year of Publication
2018
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Topic
Connections
Fire
Keywords
Adhesive
Fire Tests
Polyurethane
1C PUR
Melamine Urea Formaldehyde
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
Cross-laminated timber (CLT) became a popular engineered wood product in recent years for highquality and innovative timber buildings. As for any building product, the fire behaviour of CLT panels requires careful evaluation in the design of such buildings. The adhesive used in the bond lines of CLT plays an important role in the fire design. However, currently, European standards do not provide a test method to assess the adhesive performance in CLT exposed to fire. This paper presents a series of fire tests performed with CLT panels glued with different adhesives. It is shown how the mass loss of the CLT panels in standard fire resistance tests can be used to assess the adhesive performance in CLT exposed to fire.
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Behavior of timber-concrete composite with defects in adhesive connection

https://research.thinkwood.com/en/permalink/catalogue3108
Year of Publication
2022
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Application
Floors
Author
Buka-Vaivade, Karina
Serdjuks, Dmitrijs
Organization
Riga Technical University
Publisher
Elsevier
Year of Publication
2022
Format
Conference Paper
Material
Timber-Concrete Composite
Application
Floors
Topic
Mechanical Properties
Keywords
Adhesive Connection
Rigid Connection
Conference
ICSI 2021 The 4th International Conference on Structural Integrity
Research Status
Complete
Series
Procedia Structural Integrity
Summary
Rigid timber to concrete connection is the most effective solution for timber-concrete composite members subjected to the flexure which provides full composite action and better structural behaviour. One of the most used technologies to produce glued connection of the timber-concrete composite is “dry” method, which includes gluing together of timber and precast concrete slab. This technique has high risk of forming a poor-quality rigid connection in timber-concrete composite, and there are difficulties in controlling the quality of the glued connection. The effect of the non-glued areas in connection between composite layers on the shear stresses and energy absorption were investigated by finite element method and laboratorian experiment. Three timber-concrete composite panels in combination with carbon fibre reinforced plastic composite tapes in the tension zone with the span 1.8 m were statically loaded till the failure by the scheme of three-point bending. Mid-span displacements were measured in the bending test. One specimen was produced by dry method, by gluing together cross-laminated timber panel and prefabricated concrete panel. Timber-concrete qualitative connection of the other two specimens was provided by the granite chips, which were glued on the surface of the cross-laminated timber by epoxy, and then wet concrete was placed. Dimensions of the crushed granite pieces changes within the limits from 16 to 25 mm. The investigated panel with different amount and sizes of non-glued areas in the timber to concrete connection was numerically modelled. Obtained results shown, that the increase of shear stresses is influenced not so much by a total amount of non-glued areas, but by the size of the individual defective areas. Moreover, large non-glued areas significantly reduce the energy absorption of elements subjected to the flexure, which was observed experimentally for defective panel produced by the classical dry method with almost 4 times larger mid-span displacements than for panel with full composite action provided by the proposed production technology of the timber to concrete rigid connection. So, the proposed technology based on the use of granite chips, provides a high-quality connection between timber and concrete layers, with insignificant ration between possible defect and total connection surface area, which is equal to the area of one granite chips edge.
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Block Shear Testing of CLT Panels: An Exploratory Study

https://research.thinkwood.com/en/permalink/catalogue2624
Year of Publication
2011
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Casilla, Romulo
Pirvu, Ciprian
Wang, Brad
Lum, Conroy
Organization
FPInnovations
Year of Publication
2011
Format
Report
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Adhesive
Block Shear Test
Failure
Research Status
Complete
Summary
A study was conducted with the primary objective of examining the efficacy of a standard block shear test method to assess the bond quality of cross-laminated timber (CLT) products. The secondary objective was to examine the effect of pressure and adhesive type on the block shear properties of CLT panels. The wood material used for the CLT samples was Select grade nominal 25 x 152-mm (1 x 6-inch) Hem-Fir. Three adhesive types were evaluated under two test conditions: dry and vacuum-pressure-dry (VPD), the latter as described in CSA standard O112.10. Shear strength and wood failure were evaluated for each test condition. Among the four properties evaluated (dry and VPD shear strength, and dry and VPD wood failure), only the VPD wood failure showed consistency in assessing the bond quality of the CLT panels in terms of the factors (pressure and adhesive type) evaluated. Adhesive type had a strong effect on VPD wood failure. The different performance levels of the three adhesives were useful in providing insights into how the VPD block shear wood failure test responds to significant changes in CLT manufacturing parameters. The pressure used in fabricating the CLT panels showed a strong effect on VPD wood failure as demonstrated for one of the adhesives. VPD wood failure decreased with decreasing pressure. Although dry shear wood failure was able to detect the effect of pressure, it failed to detect the effect of adhesive type on the bond quality of the CLT panels. These results provide support as to the effectiveness of the VPD block shear wood failure test in assessing the bond quality of CLT panels. The VPD conditioning treatment was able to identify poor bondline manufacturing conditions by observed changes in the mode of failure, which is also considered an indication of wood-adhesive bond durability. These results corroborate those obtained from the delamination test conducted in a previous study (Casilla et al. 2011). Along with the delamination test proposed in an earlier report, the VPD block shear wood failure can be used to assess the CLT bond quality. Although promising, more testing is needed to assess whether the VPD block shear wood failure can be used in lieu of the delamination test. The other properties studied (shear strength and dry wood failure), however, were not found to be useful in consistently assessing bond line manufacturing quality.
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Construction and Testing of Glued Laminated Timber Frames For Use in Laying Poultry Houses

https://research.thinkwood.com/en/permalink/catalogue2588
Year of Publication
2020
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Wood Building Systems
Author
Stringari, Eduardo
Petrauski, Alfredo
Petrauski, Sandra
Azevedo, Ricardo
Savaris, Gustavo
Publisher
SciELO
Year of Publication
2020
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Wood Building Systems
Topic
Design and Systems
Keywords
Adhesive
Structural Behavior
Rural Buildings
Araucaria angustifolia
Research Status
Complete
Series
Engenharia Agrícola
Summary
This study aimed to present a solution in glued laminated timber to replace frame structures built in reinforced concrete and metallic structure, which are common in agricultural buildings in western Paraná such as those destined to laying poultry house building by agricultural cooperatives. Structural behavior of frames build from Araucaria angustifolia glued boards and vegetable oil-based polyurethane adhesive was evaluated. Tests were carried out to characterize wood and adhesive to obtain verification/sizing parameters. Initially, a full-scale structural project was conducted to meet standard laying poultry house specifications. Afterwards, five units of straight three-articulated frames on a 1:2.5 reduced scale were designed, built, and subjected to strength tests until breaking. They were built with a 2-meter free span and a 15° slope, suitable for using metal roof tiles. The average for structure ultimate strength was 4.14 times the design load. Structures had satisfactory mechanical performance and displacements lower than those recommended by NBR 7190 (1997) standard (ABNT). Therefore, building glued frames with Parana pine boards and vegetable oil-based glue is technically feasible.
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Cost Factor Analysis for Timber–Concrete Composite with a Lightweight Plywood Rib Floor Panel

https://research.thinkwood.com/en/permalink/catalogue3100
Year of Publication
2022
Topic
Cost
Material
Timber-Concrete Composite
Application
Floors
Author
Buka-Vaivade, Karina
Serdjuks, Dmitrijs
Pakrastins, Leonids
Organization
Riga Technical University
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
Timber-Concrete Composite
Application
Floors
Topic
Cost
Keywords
Adhesive Connection
Plywood Rib Panel
Floor Vibrations
Rigid Connection
Fibre Reinforced Concrete
Research Status
Complete
Series
Buildings
Summary
With the growing importance of the principle of sustainability, there is an increasing interest in the use of timber–concrete composite for floors, especially for medium and large span buildings. Timber–concrete composite combines the better properties of both materials and reduces their disadvantages. The most common choice is to use a cross-laminated timber panel as a base for a timber–concrete composite. But a timber–concrete composite solution with plywood rib panels with an adhesive connection between the timber base and fibre reinforced concrete layer is offered as the more cost-effective constructive solution. An algorithm for determining the rational parameters of the panel cross-section has been developed. The software was written based on the proposed algorithm to compare timber–concrete composite panels with cross-laminated timber and plywood rib panel bases. The developed algorithm includes recommendations of forthcoming Eurocode 5 for timber–concrete composite design and an innovative approach to vibration calculations. The obtained data conclude that the proposed structural solution has up to 73% lower cost and up to 71% smaller self-weight. Thus, the proposed timber–concrete composite construction can meet the needs of society for cost-effective and sustainable innovative floor solutions.
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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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32 records – page 1 of 4.