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45 records – page 1 of 5.

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
Country of Publication
United States
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
Language
English
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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Mechanical Behaviour of Finger Joints at Elevated Temperatures

https://research.thinkwood.com/en/permalink/catalogue612
Year of Publication
2012
Topic
Fire
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Frangi, Andrea
Bertocchi, Marco
Clauß, Sebastian
Niemz, Peter
Publisher
Springer-Verlag
Year of Publication
2012
Country of Publication
Germany
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Fire
Mechanical Properties
Keywords
Fire Resistance
Tensile tests
Bending Tests
Finger Joints
Language
English
Research Status
Complete
Series
Wood Science and Technology
ISSN
1432-5225
Summary
Finger joints are commonly used to produce engineered wood products like glued laminated timber beams. Although comprehensive research has been conducted on the structural behaviour of finger joints at ambient temperature, there is very little information about the structural behaviour at elevated temperature. A comprehensive research project on the fire resistance of bonded timber elements is currently ongoing at the ETH Zurich. The aim of the research project is the development of simplified design models for the fire resistance of bonded structural timber elements taking into account the behaviour of the adhesive used at elevated temperature. The paper presents the results of a first series of tensile and bending tests on specimens with finger joints pre-heated in an oven. The tests were carried out with different adhesives that fulfil current approval criteria for the use in loadbearing timber components. The results showed substantial differences in temperature dependant strength reduction and failure between the different adhesives tested. Thus, the structural behaviour of finger joints at elevated temperature is strongly influenced by the behaviour of the adhesive used for bonding and may govern the fire design of engineered wood products like glued laminated timber beams.
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Chapter 6: Fire Damage of Wood Structures

https://research.thinkwood.com/en/permalink/catalogue897
Year of Publication
2012
Topic
Fire
Mechanical Properties
Material
Solid-sawn Heavy Timber
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Author
Kukay, Brian
White, Robert
Woeste, Frank
Publisher
International Code Council
Year of Publication
2012
Country of Publication
United States
Format
Book/Guide
Material
Solid-sawn Heavy Timber
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Topic
Fire
Mechanical Properties
Keywords
Bending Tests
Withdrawal Tests
Load Bearing Capacity
Charring
Reduced Cross Section Method
Language
English
Research Status
Complete
Series
Inspection, Testing, and Monitoring of Buildings and Bridges
Summary
Depending on the severity, fire damage can compromise the structural integrity of wood structures such as buildings or residences. Fire damage of wood structures can incorporate several models that address (1) the type, cause, and spread of the fire, (2) the thermal gradients and fire-resistance ratings, and (3) the residual load capacity. The investigator should employ engineering judgment to identify those in-service members that are to be replaced, repaired, or can remain in-service as they are. Suchjudgment will likely be based on the visual inspection of damaged members, connections, and any protective membranes.
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Prefabricated Timber-Concrete Composite System

https://research.thinkwood.com/en/permalink/catalogue910
Year of Publication
2012
Topic
Design and Systems
Mechanical Properties
Connections
Material
Timber-Concrete Composite
Application
Floors
Author
Moar, Franco
Organization
Lund University
Year of Publication
2012
Country of Publication
Sweden
Format
Thesis
Material
Timber-Concrete Composite
Application
Floors
Topic
Design and Systems
Mechanical Properties
Connections
Keywords
FE model
Bending Tests
Withdrawal Tests
Compression Tests
Self-Tapping Screws
Prefabrication
Language
English
Research Status
Complete
Summary
Timber-concrete composite structures were originally developed for upgrading existing timber oors, but during last decades, they have new applications in multistorey buildings. Most of the research performed on these structures has focused on systems in which wet concrete is cast on top of timber beams with mounted connectors. Recently investigations on composite systems were performed at Luleå University of Technology in Sweden, in which the concrete slab is prefabricated off-site with the connectors already embedded and then connected on-site to the timber joists. Similar studies have been carried out also on timber-concrete composite structures with prefabricated FRC slabs at Lund University in Sweden. Two kinds of shear connectors were incorporated in the prefabricated FRC concrete slabs. These last systems can be considered globally as partially prefabricated structures because only the slabs were cast off-site with already inserted shear connectors and then the connection with the timber beams is done on the building site. An innovative composite system for floor applications is presented in this thesis. The entire structure is prefabricated off-side, transported and direct mounted to the building on site, that can be seen as full prefabricated structures. Noticeable benefits of a full prefabricated structure are that the moving work from the building site to the workshop reduces construction costs, is more simple and fast of manufacture and erect, and of sure, has better quality, that means more durability. Self-tapping full-threaded screws to connect concrete slabs to timber beam were used. Dimensions of the composite beams and the spacing between the screws has been chosen by discussing different FE model in order to reach the optimal solution. The experimental campaign included: (i) two short-time bending tests carried out on two dierent full-scale specimens, (ii) dynamic tests conducted on one full-scale specimen, (iii) long-time bending test carried out on one full-scale specimen, (iv) compression tests on three cubes of concrete, (v) nine withdrawal tests of the screws with different depth in the concrete. The results of the experimental tests show that the composite beams have a very high level of resistance and stiffness and also allow to reach a high degree of efficiency. Last, comparisons between FE results, analytical calculations and experimental values have been performed and from them it can be concluded that FE model and theoretical calculations well interpret the behavior of the composite structure and provide reliable results.
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Fire Performance Requirements of Non-Load-Bearing Wood-Frame In-Fill Walls in Concrete/Steel Hybrid Buildings. Part 2 - Review of the National Building Code of Canada

https://research.thinkwood.com/en/permalink/catalogue2622
Year of Publication
2013
Topic
Fire
Material
Light Frame (Lumber+Panels)
Application
Walls
Hybrid Building Systems
Author
Lu, Ling
Organization
FPInnovations
Year of Publication
2013
Country of Publication
Canada
Format
Report
Material
Light Frame (Lumber+Panels)
Application
Walls
Hybrid Building Systems
Topic
Fire
Keywords
Non-Loadbearing
Fire Resistance
Concrete
Steel
Building Code
Fire Performance
Exterior Wall
Sprinklers
Mid-Rise
Language
English
Research Status
Complete
Summary
This project evaluates the National Building Codes of Canada (NBCC) clauses relevant to fire performance and performance requirements of non-load-bearing wood-frame in-fill walls in concrete/steel hybrid buildings. Related clauses in NBCC are reviewed regarding the use of wood components and non-load bearing wall systems in non-combustible buildings. The highlights of this review are: § An exterior non-loadbearing wall assembly with combustible components is allowed in non-combustible construction if: a) Building height is not more than 3 storeys or has a sprinkler system throughout ; b) The interior surfaces of the wall assembly are protected by a thermal barrier ; and c) The wall assembly satisfied the testing criteria for CAN/ULC S134 ; § Combustible interior wall finishes, other than foamed plastics, are allowed in non-combustible construction if the thickness is not greater than 25 mm and their flame spread rating (FSR) is not more than 150 ; § Combustible insulation, other than foamed plastics, is allowed in non-combustible construction if the flame-spread rating not more than 25 ; § Combustible insulation with a FSR not less than 25 and not more than 500 is allowed in exterior and interior walls of non-combustible construction if the building is non-sprinklered and not more than 18 m or sprinklered and protected by a thermal barrier ; § There are no obstacles for using wood-frame in-fill wall systems for interior partition walls in hybrid buildings: a) For non-sprinklered buildings not greater than 3 storeys or a floor area not greater than 600 m2 ; b) For sprinklered buildings. § Non-combustible construction allows combustible elements in partition walls in the following instances: a) Solid lumber partitions located in a fire compartment area are permitted in a non-sprinklered floor area not greater than 600 m2 with restrictions ; b) Solid lumber partitions not less than 38 mm thick and partitions that contain wood framing are permitted with restrictions. § Combustible cladding can be used under the following circumstances: a) When a wall assembly with exposing building face is between 10 to 25% tested by CAN/ULC-S134 and complies with Article 3.1.5.5 ; b) When a wall assembly with exposing building face is between 25 to 50%, is sprinklered throughout, installed on a gypsum board sheathing, and has a FSR not more than 25 (with restrictions) ; c) When a wall assembly with exposing building face is between 50 to 100%, cladding can be combustible for group A, B, C, D, E, F. § When a building is required to be of non-combustible construction, combustible elements are limited to the requirements in Subsection 3.1.5 on non-combustible construction ; § When comparing the NBCC with the International Building Code (IBC), the IBC is more in favour of using FRT wood frame in-fill walls with one more storey.
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CLT Fire Resistance Tests in Support of Tall Wood Building Demonstration Projects

https://research.thinkwood.com/en/permalink/catalogue1882
Year of Publication
2014
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems

Development of Southern Pine Cross-Laminated Timber for Building Code Acceptance

https://research.thinkwood.com/en/permalink/catalogue474
Year of Publication
2014
Topic
Acoustics and Vibration
Fire
Mechanical Properties
Market and Adoption
Material
CLT (Cross-Laminated Timber)
Author
Hindman, Daniel
Bouldin, John
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Acoustics and Vibration
Fire
Mechanical Properties
Market and Adoption
Keywords
Southern Pine
Fire Performance
Acoustical Performance
International Building Code
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The current interest and growth of cross laminated timber (CLT) products has spurred interest in the manufacture of CLTs in the United States. The purpose of this paper is to explore the development of CLT materials from southern pine lumber commonly available in Virginia. A 5-layer CLT panel has been constructed using No. 2 southern pine lumber. Evaluation of mechanical properties, fire performance and acoustical performance were conducted. Results of these evaluations can guide the development and acceptance of CLT products in the International Building Code.
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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
Country of Publication
Canada
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Topic
Fire
Mechanical Properties
Keywords
Box Beams
Post-Tensioned
Fire Performance
Shear Strength
Language
English
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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Thin Topping Timber-Concrete Composite Floors

https://research.thinkwood.com/en/permalink/catalogue902
Year of Publication
2014
Topic
Design and Systems
Mechanical Properties
Material
Timber-Concrete Composite
Application
Floors
Author
Skinner, Jonathan
Organization
University of Bath
Year of Publication
2014
Country of Publication
United Kingdom
Format
Thesis
Material
Timber-Concrete Composite
Application
Floors
Topic
Design and Systems
Mechanical Properties
Keywords
Stiffness
Vibration Response
Topping Thickness
Screws
shear connectors
Static Loads
Cyclic Loads
Short-term
Bending Tests
Language
English
Research Status
Complete
Summary
A timber-concrete composite (TCC) combines timber and concrete, utilising the complementary properties of each material. The composite is designed in such a way that the timber resists combined tension and bending, whilst the concrete resists combined compression and bending. This construction technique can be used either in new build construction, or in refurbishment, for upgrading existing timber structures. Its use is most prolific in continental Europe, Australasia, and the United States of America but has yet to be widely used in the United Kingdom. To date, the topping upgrades used have been 40mm thick or greater. Depending on the choice of shear connection, this can lead to a four-fold increase in strength and stiffness of the floor. However, in many practical refurbishment situations, such a large increase in stiffness is not required, therefore a thinner topping can suffice. The overarching aim of this study has been to develop a thin (20mm) topping timber-concrete composite upgrade with a view to improving the serviceability performance of existing timber floors. Particular emphasis was given to developing an understanding of how the upgrade changes the stiffness and transient vibration response of a timber floor. Initially, an analytical study was carried out to define an appropriate topping thickness. An experimental testing programme was then completed to: characterise suitable shear connectors under static and cyclic loads, assess the benefit of the upgrade to the short-term bending performance of panels and floors, and evaluate the influence of the upgrade on the transient vibration response of a floor. For refurbishing timber floors, a 20mm thick topping sufficiently increased the bending stiffness and improved the transient vibration response. The stiffness of the screw connectors was influenced by the thickness of the topping and the inclination of the screws. During the short-term bending tests, the gamma method provided a non-conservative prediction of composite bending stiffness. In the majority of cases the modal frequencies of the floors tested increased after upgrade, whilst the damping ratios decreased. The upgrade system was shown to be robust as cracking of the topping did not influence the short-term bending performance of panels. Thin topping TCC upgrades offer a practical and effective solution to building practitioners, for improving the serviceability performance of existing timber floors.
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Fire Performance of Metal-Free Timber Connections

https://research.thinkwood.com/en/permalink/catalogue2186
Year of Publication
2015
Topic
Fire
Connections
Material
LVL (Laminated Veneer Lumber)
CLT (Cross-Laminated Timber)
Other Materials
Application
Wood Building Systems
Beams
Columns
Trusses
Author
Brandon, Daniel
Maluk, Cristian
Ansell, Martin
Harris, Richard
Walker, Pete
Bisby, Luke
Bregulla, Julie
Publisher
ICE Publishing
Year of Publication
2015
Country of Publication
United Kingdom
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
CLT (Cross-Laminated Timber)
Other Materials
Application
Wood Building Systems
Beams
Columns
Trusses
Topic
Fire
Connections
Keywords
Fire Performance
Steel Connections
Thermal Conductivity
Thermal Behaviour
Mechanical Behavior
Metal-Free Connections
Language
English
Research Status
Complete
Series
Proceedings of the Institution of Civil Engineers - Construction Materials
Notes
DOI link: http://dx.doi.org/10.1680/coma.14.00055
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45 records – page 1 of 5.