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7 records – page 1 of 1.

Bond strength of GiR in cross-laminated timber: A preliminary study

https://research.thinkwood.com/en/permalink/catalogue2934
Year of Publication
2021
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Sofi, M.
Lumantarna, E.
Hoult, Ryan
Mooney, Michael
Mason, Nicholas
Lu, Jinghan
Organization
The University of Melbourne
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Glued-in Rod
Pull-Out Strength
Embedment Length
Moment Connections
Research Status
Complete
Series
Construction and Building Materials
Summary
The popularity of cross-laminated timber (CLT) has increased significantly over recent years, with numerous low- to mid-rise buildings being constructed with CLT panels as the load-bearing structural system. Glued-in rods (GiR) have been used in the construction and retrofitting of timber structures and recently found its use in CLT elements. Embedded into the timber with structural grade adhesives, GiR enable stiff connections between timber and other structural members. Due to the complex force mechanisms occurring within these joints, there is yet to be consensus on a suitable method to predict their pull-out strength or failure mechanism. There is lack of experimental research on performance of GiR embedded into CLT. This paper examines previous research on glued-in rod connections as typically applied to solid timber and other engineered timber products. It aims to identify the factors contributing to the strength and failure modes of this connection, as well as the current models that are used for the analysis and design of glued-in rods. A series of 30 experiments were undertaken to investigate the load carrying capacity of single GiR bonded into CLT panels to identify the influence of (i) the bonded length of rod; and, (ii) the direction of the middle ply of the CLT panel on these results. The experimental results indicate that the pull-out strength is largely dictated by the embedment length.
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Connection and Performance of Two-Way CLT Plates

https://research.thinkwood.com/en/permalink/catalogue1482
Year of Publication
2018
Topic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
Application
Floors
Roofs
Author
Zhang, Chao
Lee, George
Lam, Frank
Organization
University of British Columbia
Year of Publication
2018
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Floors
Roofs
Topic
Mechanical Properties
Connections
Keywords
Two-Way
Bending Test
Modulus of Elasticity
Self-Tapping Screws
Glued-In-Rod
Steel Connectors
Steel Plates
Research Status
Complete
Summary
The two-way action of Cross Laminated Timber (CLT) is often ignored in the design of CLT due to its complexity. But in some cases, for example, large span timber floor/roof, the benefit of taking the two-way action into account may be considerable since it is often deflection controlled in the design. Furthermore CLT panels are typically limited to widths of less than 3 m. therefore, for practical applications, engaging CLT panels in two-way action as a plate in bending would require connecting two panels in the width/minor direction to take out-of-plane loading. To address this technically difficult situation, an innovative connection was developed to join the CLT panels in the minor direction to form a large continuous two-way plate. The two-way action of CLT was also quantified. Static bending test was conducted on CLT panels in the major and minor directions to measure the Modulus of Elasticity (MOE). This provided a benchmark for the following connection test, and data for the future development of computer modeling. The average apparent MOE was 9.09 GPa in the major direction and 2.37 GPa in the minor direction. Several connection techniques were considered and tested, including self-tapping wood screws, glued in steel rods, and steel connectors. One connecting system was found to be effective. For the panel configuration considered, the system was consisted of steel plates, self-tapping wood screws, and 45° screw washers. Two steel plates were placed on the tension side with sixteen screws, and one steel plates was placed on the compression side with four screws. When the screws were driven into the wood, the screws were tightly locked with the washers and steel plates, and at the same time, the wood members were pulled together by the screws. This eliminated any original gap within the connection. The connector was installed to join two CLT members in the minor direction. They were tested under bending with the same setup as above. The connected panels had an average apparent MOE of 2.37 GPa, and an average shear-free MOE of 2.44 GPa, both of which were higher than the counterpart in the full panels. The moment capacity of the connected panels was also high. The minimum moment capacity was 3.2 times the design value. Two large CLT panels were tested under concentrated loading with four corners simply supported. The deflection of nine locations within the panels was measured. This data will be used to validate the computer modeling for CLT two-way action.
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Experimental Investigation on the Fire Resistance of Glued-In Rod Timber Joints with Heat Resistant Modified Epoxy Resin

https://research.thinkwood.com/en/permalink/catalogue2665
Year of Publication
2020
Topic
Fire
Connections
Material
Glulam (Glue-Laminated Timber)
Author
Luo, Liquan
Shi, Benkai
Liu, Weiqing
Yang, Huifeng
Ling, Zhibin
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Fire
Connections
Keywords
Fire Resistance
Glued-In Rod Joint
Glued-In Rod Timber Joint
Pull-Out Test
Heat Resistant
Modified Epoxy Resin
Adhesive
Research Status
Complete
Series
Materials
Summary
This paper presents an experimental evaluation of the fire resistance of glued-in rod timber joints using epoxy resin, with and without modification. A heat-resistant modified resin was designed by adding inorganic additives into the epoxy resin, aiming to improve the heat resistance. Joints that were made using the modified epoxy resin at room temperature showed a bearing capacity comparable to those with commercial epoxy resin. Twenty-one joint specimens with the modified epoxy resin and six with a commercial epoxy resin were tested in a fire furnace to evaluate the fire resistance. The main failure mode was the pull-out of the rod, which is typical in fire tests of this type of joints. As to the effects of the test parameters, this study considered the effects of adhesive types, sectional sizes, stress levels, and fireproof coatings. The test results showed that the fire resistance period of a joint can be evidently improved by modifying the resin and using the fireproof coating, as the improvements reached 73% and 35%, respectively, compared with the joint specimens with commercial epoxy resin. It was also found that, for all specimens, the fire resistance period decreased with an increase in the stress level and increased with an increase in the sectional sizes.
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Numerical Simulation on Bond Behavior Between Glulam and Glued-In Rod

https://research.thinkwood.com/en/permalink/catalogue1607
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Ling, Zhibin
Liu, Weiqing
Yang, Huifeng
Lu, Weidong
Year of Publication
2016
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Glued-In-Rod
Joints
Numerical Simulation
Stress-Slip
Bond Behavior
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2093-2099
Summary
Glued-in rod is a type of effective connector for timber structures. In the last decades, considerable researches have been conducted on the bond behavior between timber and glued-in rod experimentally and theoretically. This paper presents the numerical simulation on the bond behavior of glulam joints with glued-in steel rod. Glulam is modelled as the orthotropic elasto-plastic material. Adhesive and steel rods are modelled as isotropic materials. Non-linear spring element was employed to simulate the local bond stress-slip relations at different locations along the bonded length. The numerical results indicate that non-linear spring element can be used to simulate the bond behavior of the glued-in steel rod glulam joints effectively. Moreover, The numerical results obtained by considering the local bond relations at different locations is in a better agreement with the experimental results than that obtained based on the bond stress-slip relation at loaded end.
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Pull-Out Strength of Glued-In Rod Joints from LVL

https://research.thinkwood.com/en/permalink/catalogue686
Year of Publication
2014
Topic
Design and Systems
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Author
Ito, Kazutoshi
Lee, Wonwoo
Song, Changsuk
Tanaka, Kei
Koshihara, Mikio
Inoue, Masafumi
Year of Publication
2014
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Topic
Design and Systems
Mechanical Properties
Keywords
Pull-Out Tests
Glued-in rod joint
Strength
Temporary Loading
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Recently, the Japanese government enacted a new law in order to promote large wooden building. As a result, the momentum in the construction of large wooden building especially multi-stories wooden buildings in local area has been growing rapidly. In order to achieve these buildings, the higher structural performances than that by usual technique are required.GIR joint system is widely adapted for the joint part of wooden structures. Glued in rod joint-system(GIR) have high strength and high rigidity compared to existing joint-system. On the other hand, the structural LVL with the flexibility performance of cross-section and high structural performance is expected as a material for multi-stories wooden building. So, in this study, the pull-out tests of GIR joints inserted to structural LVL are carried out. And structural characteristics of this type of joint is discussed. Maximum strength and allowable load for temporary loading obtained by pull-out tests are presented.
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Resumption of Lateral Loads in a Massive Structure Assembled by Glued Rods

https://research.thinkwood.com/en/permalink/catalogue2674
Topic
Mechanical Properties
Organization
Université Laval
Topic
Mechanical Properties
Keywords
Glued-In-Rod
Creep
Lateral Loading
Research Status
In Progress
Notes
Project contact is Sylvain Ménard at Université Laval
Summary
Assemblies by glued rods allow architectural freedom. They are in fact invisible since they are found in the mass of the structural element. Some studies have started to document this type of assembly by considering static single-rod traction tests and single-rod creep tests (Verdet, 2016). In order to continue this effort to specify the limits of this type of assembly, it is proposed to consider the lateral forces for single-rod assemblies but especially multi-rods. The objective of this project will therefore be to document the capacity of these assemblies to take up lateral loads.
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Study of the Seismic and Dynamic Behavior of Glued Rod Assemblies

https://research.thinkwood.com/en/permalink/catalogue2668
Topic
Mechanical Properties
Seismic
Connections
Application
Frames
Organization
Université Laval
Application
Frames
Topic
Mechanical Properties
Seismic
Connections
Keywords
Energy Dissipation
Cyclic Loads
Glued-In-Rod
Beam-Column Connection
Research Status
In Progress
Notes
Project contact is Jean Proulx at Université Laval
Summary
The main objective of the research project is to assess the behavior of bonded rod assemblies under dynamic stresses. These wood / wood connections are used in solid wood frames and allow, among other things, to transfer the moment in beam-column connections. Their ability to dissipate energy under seismic loading will be evaluated by cyclic laboratory tests by varying the sections and configurations of the assemblies. The whole structure must be able to dissipate energy under dynamic loadings (earthquakes, wind) and the demand for ductility in the assemblies is considerable in rigid frame structures. This project will make it possible to characterize the behavior of timber / timber assemblies in glued rods under cyclic loads. The results obtained can be used by the partner for the seismic design of solid wood structures using these connections. Optimization and a better understanding of the dynamic behavior of these assemblies will also increase the safety of solid wood structures, and promote their acceptance in this developing market.
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7 records – page 1 of 1.