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62 records – page 1 of 7.

Experimental Behavior of a Continuous Metal Connector for a Wood-Concrete Composite System

https://research.thinkwood.com/en/permalink/catalogue730
Year of Publication
2004
Topic
Connections
Design and Systems
Mechanical Properties
Material
Timber-Concrete Composite
PSL (Parallel Strand Lumber)
Application
Floors
Author
Clouston, Peggi
Civjan, Scott
Bathon, Leander
Publisher
Forest Products Society
Year of Publication
2004
Format
Journal Article
Material
Timber-Concrete Composite
PSL (Parallel Strand Lumber)
Application
Floors
Topic
Connections
Design and Systems
Mechanical Properties
Keywords
Pine
US
Continuous Steel Mesh
Steel Connectors
Push-Out Tests
Shear Strength
Stiffness
Bending Tests
Research Status
Complete
Series
Forest Products Journal
Summary
The benefits of using shear connectors to join wood beams to a concrete slab in a composite floor or deck system are many. Studies throughout the world have demonstrated significantly improved strength, stiffness, and ductility properties from such connection systems as well as citing practical building advantages such as durability, sound insulation, and fire resistance. In this study, one relatively new shear connector system that originated in Germany has been experimentally investigated for use with U.S. manufactured products. The connector system consists of a continuous steel mesh of which one half is glued into a southern pine Parallam® Parallel Strand Lumber beam and the other half embedded into a concrete slab to provide minimal interlayer slip. A variety of commercial epoxies were tested for shear strength and stiffness in standard shear or “push out” tests. The various epoxies resulted in a variety of shear constitutive behaviors; however, for two glue types,shear failure occurred in the steel connector resulting in relatively high initial stiffness and ductility as well as good repeatability. Slip moduli and ultimate strength values are presented and discussed. Full-scale bending tests, using the best performing adhesive as determined from the shear tests, were also conducted. Results indicate consistent, near-full composite action system behavior.
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Experimental and Numerical Investigation on the Shear Strength of Glulam

https://research.thinkwood.com/en/permalink/catalogue2237
Year of Publication
2010
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Crocetti, Roberto
Gustafsson, Per-Johan
Danielsson, Henrik
Emilsson, Arne
Ormarsson, Sigurdur
Organization
Lund University
Technical University of Denmark
Year of Publication
2010
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Keywords
Shear Strength
Shear Loading
Boundary Conditions
Conference
CIB-W18 Meeting
Research Status
Complete
Summary
The general objective of this study is to gain a better knowledge on the shear strength of glulam subjected to predominant shear loading and with different boundary conditions. Specific objectives include the following: - Propose a practical setup for testing glulam in shear which does not generate too large secondary stresses in the specimen, e.g. perpendicular to the grain stresses. - Investigate the shear strength of glulam specimens both with I-cross section and with rectangular cross section. - Investigate the influence of growth ring orientation on the shear strength of glulam.
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Shear Resistance of Glulam Beams with Cracks

https://research.thinkwood.com/en/permalink/catalogue997
Year of Publication
2012
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Pousette, Anna
Ekevad, Mats
Year of Publication
2012
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Cracks
Shear Strength
Three Point Bending Test
Conference
CIB-W18 Meeting
Research Status
Complete
Notes
August 27-30, 2012, Växjö, Sweden p. 257-265
Summary
A reduction of the shear resistance was introduced with the crack factor kcr in Eurocode 5. The factor 0.67 corresponds to cracks that have a depth of 1/3 of the beam width. The aim of this project was to learn more about different types of cracks and their importance for the shear strength of glulam beams. The project started with tests of five types of glulam beams, with or without cracks. The cracks had different depths and locations, three beam types had cracks made by sawing and one type had cracks from moisturing and drying. The beam dimensions were 115 mm x 315 mm x 2600 mm. Five beams of each type with cracks were tested and ten beams without cracks. The beams were Swedish standard beams made of Spruce and taken from the normal production. Three-point bending method was used for the shear tests. The beams of type 1 without cracks got mostly bending failures; the characteristic shear strength was at least 3.5 MPa. Beams with sawn grooves got lower characteristic shear values and this means a reduced cross section should be used for beams with cut grooves along the beams. Beams with drying cracks got more shear failures, but the characteristic shear strength of the beams was about the same as for beams without cracks.
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Performance Evaluation of Phenol Formaldehyde Resin-Impregnated Veneers and Lamminated Veneer Lumber

https://research.thinkwood.com/en/permalink/catalogue1444
Year of Publication
2012
Topic
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Author
Wang, Brad
Chui, Ying Hei
Publisher
Society of Wood Science and Technology
Year of Publication
2012
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Topic
Mechanical Properties
Keywords
Mountain Pine Beetle
Lodgepole Pine
Resin Impregnation
Modulus of Elasticity
Phenol Formaldehyde
Dimensional Stability
Hardness
Bending Strength
Bending Modulus
Shear Strength
Research Status
Complete
Series
Wood and Fiber Science
Summary
For the past decade, mountain pine beetle infestation in British Columbia, Canada, has substantially changed wood characteristics of vast amounts of the lodgepole pine (Pinus contorta) resource. Resin impregnation is one method that could improve the properties of the beetle-affected wood. The key objective of this study was to examine the impact of resin impregnation on dynamic MOE of lodgepole pine veneers and properties of laminated veneer lumber (LVL) made with these treated veneers. A new phenol formaldehyde resin was formulated to treat these veneers using dipping and vacuum-pressure methods. Five-ply LVL billets were made with treated and untreated veneers. Their color, dimensional stability, surface hardness, flatwise bending modulus and strength, and shear strength were evaluated. Good correlation existed between veneer MOE enhancement and resin solids uptake. With the same treatment, stained veneers had higher resin retention and in turn greater MOE enhancement than nonstained (clear) veneers. A 5-min dipping was sufficient for veneers to achieve approximately 7 and 10% resin solids uptake and in turn 5 and 8% enhancement in veneer MOE for nonstained and stained veneers, respectively. LVL made with treated veneers had a harder surface with no discoloration concerns compared with the control. Also, evidence suggested that use of resin impregnation can improve dimensional stability, shear strength, and flatwise bending MOE of LVL.
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In Plane Shear Strength of Cross Laminated Timber (CLT): Test Configuration, Quantification and influencing Parameters

https://research.thinkwood.com/en/permalink/catalogue2121
Year of Publication
2013
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Brandner, Reinhard
Bogensberger, Thomas
Schickhofer, Gerhard
Organization
Graz University of Technology
Year of Publication
2013
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Mechanical Properties
Keywords
Shear Resistance
Shear Loads
In-Plane Shear Strength
Single Nodes
Net-Shear
Conference
International Council for Research and Innovation in Building and Construction, Working Commission W18 - Timber Structures
Research Status
Complete
Summary
Cross laminated timber (CLT) has become a well-known and widely applied two-dimensional, engineered timber product worldwide. It constitutes a rigid composite of an odd number of orthogonal and glued layers. Focusing on a single glued node loaded in plane in shear and composed of two crossed board segments and the adhesive layer in-between, in principle three types of shear mechanisms can be distinguished: mechanism I "net-shear" (shearing perpendicular to grain), mechanism II "torsion" and mechanism III "gross-shear" (shearing parallel to grain). In fact, while having generally accepted values for the resistance against mechanism II and good estimates for mechanism III the resistance against "net-shear" (mechanism I) is still in discussion. In spite of numerous investigations on nodes and on whole CLT elements in the past, a common sense concerning the test procedure, the consideration and handling of distinct influencing parameters and the quantification of the shear strength are open. We focus on the in plane shear resistance of single nodes according to mechanism I. We (i) propose a test configuration for reliable determination of the shear strength, (ii) determine the shear resistance in case of shear loads perpendicular to grain, (iii) discuss influences of some parameters on the shear strength of single nodes, and (iv) give a brief outlook concerning the resistance of CLT elements against shear loads in plane.
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Evaluating Rolling Shear Strength Properties of Cross Laminated Timber by Torsional Shear Tests and Bending Test

https://research.thinkwood.com/en/permalink/catalogue307
Year of Publication
2014
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Li, Minghao
Lam, Frank
Li, Yuan
Year of Publication
2014
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
SPF
Polyurethane
Rolling Shear Strength
Torsional Shear Test
Bending Test
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
This paper presents a study on evaluating rolling shear (RS) strength properties of cross laminated timber (CLT) using torsional shear tests and bending tests. The CLT plates were manufactured with Spruce-Pine-Fir boards and glued with polyurethane adhesive. Two types of layups (3-layer and 5-layer) and two clamping pressures (0.1 MPa and 0.4 MPa) were studied. For the torsional shear tests, small shear block specimens were sampled from the CLT plates and the cross layers were processed to have an annular cross section. Strip specimens were simply sampled from the CLT plates for the bending tests. Based on the failure loads, RS strength properties were evaluated by torsional shear formula, composite beam formulae as well as detailed finite element models, respectively. It was found that the two different test methods yielded different average RS strength value for the same type of CLT specimens. The test results showed that the CLT specimens pressed with the higher clamping pressure had slightly higher average RS strength. The specimens with thinner cross layers also had higher RS strength than the specimens with thicker cross layers.
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Thermo-Mechanical Behavior of Timber in Shear: An Experimental Study

https://research.thinkwood.com/en/permalink/catalogue505
Year of Publication
2014
Topic
Fire
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Audebert, Maxime
Dhima, Dhionis
Bouchaïr, Abdelhamid
Racher, Patrick
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Fire
Mechanical Properties
Keywords
Shear Strength
Temperature
Reduction Factors
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The advanced calculation methods for wood structural elements in fire situations proposed by EN1995-1-2 provide reduction factors of wood strength according to the temperature. The values of these reduction factors given for compression and tension strength are relatively well documented. However, the reduction factors of wood shear strength with temperature were not studied. This study concerns experimental investigations conducted to characterize the evolution with temperature of the shear strength of wood. The tests are realized using a specific original specimen specially developed for this study. The experimental results allow evaluating the values given in EN1995-1-2.
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Shear Strength of LVL Box Beams in Fire Conditions

https://research.thinkwood.com/en/permalink/catalogue540
Year of Publication
2014
Topic
Fire
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Author
Costello, Reuben
Abu, Anthony
Moss, Peter
Buchanan, Andrew
Year of Publication
2014
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Topic
Fire
Mechanical Properties
Keywords
Box Beams
Post-Tensioned
Fire Performance
Shear Strength
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
This paper outlines a series of experimental tests of LVL box beams designed to fail in shear. Some beams utilised post-tensioning systems to increase the flexural strength and decrease deflection. Fire conditions were simulated using either an ISO 834 furnace test or by mechanically reducing the section dimensions on three-sides of the beam to replicate charring. Comparisons with a simplified calculation method for the fire performance of post-tensioned timber box beams are made and discussed. This paper gives special focus to the shear performance of LVL box beams because previous research had identified that the inclusion of post-tensioning may increase the likelihood of shear failure occurring in LVL box beams, especially in fire conditions.
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Shear Tests of Glulam at Elevated Temperatures

https://research.thinkwood.com/en/permalink/catalogue563
Year of Publication
2014
Topic
Fire
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Dhima, Dhionis
Audebert, Maxime
Racher, Patrick
Bouchaïr, Abdelhamid
Taazount, Mustapha
Publisher
Wiley Online Library
Year of Publication
2014
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Fire
Mechanical Properties
Keywords
Density
Shear Strength
Temperature
Thermal Gradient
Research Status
Complete
Series
Fire and Materials
Summary
Experimental investigations are conducted to characterize the evolution with temperature of the shear strength of glulam wood. To realize the tests, an original specimen with cylindrical shape has been developed and justified by a numerical study. The geometry allows obtaining thermal gradient within material to represent the real combustion of timber members, while keeping constant the temperature of sheared section. The experimental programs consider various parameters such as the presence or absence of moisture and the thermal gradient within the specimen. The experimental results are discussed and analyzed. They show the correlation between the density of the material and the reduction of its strength at high temperatures. The experimental failure loads are used to evaluate the reduction factors for wood strength depending on the temperature. These factors are compared with those given by EN1995-1-2 for the advanced calculations methods in fire situation. The comparisons show that the reduction factors given by EN1995-1-2 are conservative in comparison with the experimental results. Copyright © 2014 John Wiley & Sons, Ltd.
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Applicability of Various Wood Species in Glued Laminated Timber - Parameter Study on Delamination Resistance and Shear Strength

https://research.thinkwood.com/en/permalink/catalogue592
Year of Publication
2014
Topic
Mechanical Properties
Connections
Material
Glulam (Glue-Laminated Timber)
Author
Jiang, Yuan
Schaffrath, Jörg
Knorz, Markus
Winter, Stefan
Van de Kuilen, Jan-Willem
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Connections
Keywords
Hardwood
Softwood
Gluability
Delamination
Shear Strength
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
In a current research project the gluability of various soft- und hardwood species and their applicability in glued laminated timber are investigated. The influence of the processing parameters on the delamination resistance and shear strength of the glue lines are presented in this work. The bonding forces, which are necessary for the integrity of a glue line, act in the interface within a distance that varies from nanometers to micrometers. The parameters that may have significant influence on the bonding strength and durability of adhesive joints are numerous and depend on the type of wood, adhesive and processing conditions.
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62 records – page 1 of 7.