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24 records – page 1 of 3.

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.
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An Overview of CLT Research and Implementation in North America

https://research.thinkwood.com/en/permalink/catalogue759
Year of Publication
2016
Topic
Market and Adoption
Material
CLT (Cross-Laminated Timber)
Author
Pei, Shiling
Rammer, Douglas
Popovski, Marjan
Williamson, Tom
Line, Philip
van de Lindt, John
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Market and Adoption
Keywords
Market
North America
Building Development
Research
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria
Summary
Although not yet seen as common practice, building with cross laminated timber (CLT) is gaining momentum in North America. Behind the scenes of the widely publicized project initiatives such as the Wood Innovation Design Centre Building in Canada and the recent U.S. Tall Wood Building Competition, substantial research, engineering, and development has been completed or is underway to enable the adoption of this innovative building system. This paper presents a brief overview of the current status of CLT building development in North America, highlighting some recent U.S. and Canadian research efforts related to CLT system performance, and identifies future CLT research directions based on the needs of the North American market. The majority of the research summarized herein is from a recent CLT research workshop in Madison, Wisconsin, USA, organized by the USDA Forest Products Laboratory. The opportunity and need for coordination in CLT research and development among the global timber engineering community are also highlighted in the conclusions of this paper.
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Cross-Laminated Timber for Seismic Regions: Progress and Challenges for Research and Implementation

https://research.thinkwood.com/en/permalink/catalogue162
Year of Publication
2014
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Pei, Shiling
van de Lindt, John
Popovski, Marjan
Berman, Jeffrey
Dolan, Daniel
Ricles, James
Sause, Richard
Blomgren, Hans-Erik
Rammer, Douglas
Publisher
American Society of Civil Engineers
Year of Publication
2014
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Seismic
Keywords
Lateral Loads
Prefabrication
US
Research Status
Complete
Series
Journal of Structural Engineering
Summary
Compared to light-frame wood shear walls, it is relatively difficult for panelized CLT shear walls to achieve similar levels of lateral deflection without paying special attention to design details, i.e., connections. A design lacking ductility or energy dissipating mechanism will result in high acceleration amplifications and excessive global overturning demands for multistory buildings, and even more so for tall wood buildings. Although a number of studies have been conducted on CLT shear walls and building assemblies since the 1990s, the wood design community’s understanding of the seismic behavior of panelized CLT systems is still in the learning phase, hence the impetus for this article and the tall CLT building workshop, which will be introduced herein. For example, there has been a recent trend in engineering to improve resiliency, which seeks to design a building system such that it can be restored to normal functionality sooner after an earthquake than previously possible, i.e., it is a resilient system. While various resilient lateral system concepts have been explored for concrete and steel construction, this concept has not yet been realized for multistory CLT systems. This forum article presents a review of past research developments on CLT as a lateral force-resisting system, the current trend toward design and construction of tall buildings with CLT worldwide, and attempts to summarize the societal needs and challenges in developing resilient CLT construction in regions of high seismicity in the United States.
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Design of Multiple Bolted Connections for Laminated Veneer Lumber

https://research.thinkwood.com/en/permalink/catalogue252
Year of Publication
2014
Topic
Connections
Design and Systems
Material
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Author
Yeh, Borjen
Rammer, Douglas
Linville, Jeff
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Topic
Connections
Design and Systems
Keywords
National Design Specifications for Wood Construction (NDSR)
Failure Modes
Bolted Connection
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The design of multiple bolted connections in accordance with Appendix E of the National Design Specification for Wood Construction (NDS) has incorporated provisions for evaluating localized member failure modes of row and group tear-out when the connections are closely spaced. Originally based on structural glued laminated timber (glulam) members made with all L1 Douglas fir-Larch laminating lumber, the NDS provisions were confirmed by additional analysis, which indicates the applicability of the provisions to glulam with reduced design shear values. Due to the similarity to glulam in the grain orientation and layup strategy, laminated veneer lumber (LVL) is subject to similar failure modes. As a result, a study was initiated by APA – The Engineered Wood Association and the LVL industry, in collaboration with the Forest Products Laboratory (FPL) of the U.S. Department of Agriculture (USDA) to evaluate if a reduced design shear stress is necessary for LVL under similar multiple bolted connection configurations. This paper describes the test results obtained from the study, which indicate that an adequate load factor exists for LVL multiple bolted connections without a reduction in the LVL design shear stress when designed in accordance with Appendix E of the NDS.
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Determination of Seismic Performance Factors for CLT Shear Wall Systems

https://research.thinkwood.com/en/permalink/catalogue770
Year of Publication
2016
Topic
Connections
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Amini, M. Omar
van de Lindt, John
Rammer, Douglas
Pei, Shiling
Line, Philip
Popovski, Marjan
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Connections
Seismic
Keywords
Angle Bracket
Cyclic Tests
US
Quasi-Static
Seismic Performance Factors
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria
Summary
This paper presents selected results of connector testing and wall testing which were part of a Forest Products Lab-funded project undertaken at Colorado State University in an effort to determine seismic performance factors for cross laminated timber (CLT) shear walls in the United States. Archetype development, which is required as part of the process, is also discussed. Connector tests were performed on generic angle brackets which were tested under shear and uplift and performed as expected with consistent nail withdrawal observed. Quasi-static cyclic tests were conducted on CLT shear walls to systematically investigate the effects of various parameters. Boundary constraints and gravity loading were both found to have a beneficial effect on the wall performance, i.e. higher strength and deformation capacity. Specific gravity also had a significant effect on wall behaviour while CLT thickness was less influential. Higher aspect ratio panels (4:1) demonstrated lower stiffness and substantially larger deformation capacity compared to moderate aspect ratio panels (2:1). However, based on the test results there is likely a lower bound of 2:1 for aspect ratio where it ceases to have any beneficial effect on wall behaviour. This is likely due to the transition from the dominant rocking behaviour to sliding behaviour.
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Developing Seismic Performance Factors for Cross Laminated Timber in the United States

https://research.thinkwood.com/en/permalink/catalogue124
Year of Publication
2015
Topic
Seismic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
van de Lindt, John
Amini, M. Omar
Rammer, Douglas
Line, Philip
Pei, Shiling
Popovski, Marjan
Organization
Canadian Association for Earthquake Engineering
Year of Publication
2015
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Seismic
Mechanical Properties
Connections
Keywords
Angle Bracket
Shear Test
Strength
Stiffness
Uplift Test
US
Conference
The 11th Canadian Conference on Earthquake Engineering
Research Status
Complete
Notes
July 21-24, 2015, Victoria, BC, Canada
Summary
This paper presents recent progress in the development of seismic performance factors for cross-laminated timber (CLT) systems in the United States. A brief overview of some of other systematic studies conducted in Europe, North America, and Japan is also provided. The FEMA P695 methodology is briefly described and selected results from connector testing and CLT wall testing are discussed. Shear and uplift tests were performed on generic angle brackets to quantify their behavior. CLT walls with these connectors were then tested investigate the influence of various parameters on wall component performance. The influential factors considered include boundary condition, gravity loading, CLT grade, panel thickness, and panel aspect ratio (height:length). Results indicate that boundary condition and gravity loading have beneficial effect on strength and stiffness of the CLT panels. CLT grade is an important parameter while CLT panel thickness only has a minimal influence on wall behavior. Higher aspect ratio (4:1) panels demonstrated less stiffness but considerably more ductility than the panels with lower aspect ratio (2:1). This paper also provides details on some ongoing efforts including additional tests planned, index buildings from which P-695 archetypes will be extracted, and nonlinear modeling for this project.
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Development and Full-Scale Validation of Resilience-Based Seismic Design of Tall Wood Buildings: The NHERI Tallwood Project

https://research.thinkwood.com/en/permalink/catalogue1477
Year of Publication
2017
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Author
Pei, Shiling
van de Lindt, John
Ricles, James
Sause, Richard
Berman, Jeffrey
Ryan, Keri
Dolan, Daniel
Buchanan, Andrew
Robinson, Thomas
McDonnell, Eric
Blomgren, Hans-Erik
Popovski, Marjan
Rammer, Douglas
Year of Publication
2017
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Tall Wood
Post-Tensioned
Rocking Walls
Resilience-Based Seismic Design
Shaking Table Test
Conference
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
April 27-29, 2017, Wellington, New Zealand
Summary
With global urbanization trends, the demands for tall residential and mixeduse buildings in the range of 8~20 stories are increasing. One new structural system in this height range are tall wood buildings which have been built in select locations around the world using a relatively new heavy timber structural material known as cross laminated timber (CLT). With its relatively light weight, there is consensus amongst the global wood seismic research and practitioner community that tall wood buildings have a substantial potential to become a key solution to building future seismically resilient cities. This paper introduces the NHERI Tallwood Project recentely funded by the U.S. National Science Fundation to develop and validate a seismic design methodology for tall wood buildings that incorporates high-performance structural and nonstructural systems and can quantitatively account for building resilience. This will be accomplished through a series of research tasks planned over a 4-year period. These tasks will include mechanistic modeling of tall wood buildings with several variants of post-tensioned rocking CLT wall systems, fragility modeling of structural and non-structural building components that affect resilience, fullscale biaxial testing of building sub-assembly systems, development of a resilience-based seismic design (RBSD) methodology, and finally a series of full-scale shaking table tests of a 10-story CLT building specimen to validate the proposed design. The project will deliver a new tall building type capable of transforming the urban building landscape by addressing urbanization demand while enhancing resilience and sustainability.
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Development of Seismic Performance Factors for Cross Laminated Timber: Phase 2

https://research.thinkwood.com/en/permalink/catalogue803
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
van de Lindt, John
Rammer, Douglas
Pei, Shiling
Organization
Forest Products Laboratory
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Seismic Performance Factors
US
Research Status
In Progress
Summary
A collaborative project between the Forest Products Laboratory and Colorado State University to develop seismic performance factors for cross laminated timber is underway. The project requires application of the FEMA P-695 methodology, which is purposely robust and detailed and requires that the project team follow specific procedures. Failure to develop these seismic performance factors would severely limit the acceptance of the CLT building systems in the United States, underscoring the need for application of the FEMA P-695. The FEMA P-695 document, “Quantification of Building Seismic Performance Factors,” was published in 2009 and defines a number of steps, all of which will be taken to develop the seismic performance factors for seismic design of CLT buildings. The objectives of this research are (1) to develop seismic performance factors for CLT subject to a peer review panel process that includes an independent peer review committee report and (2) to have the resulting seismic performance factors recognized in ASCE 7 Minimum Design Loads for Buildings and Other Structures.
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Development of Timber Buckling-Restrained Braces for Mass Timber Braced Frames

https://research.thinkwood.com/en/permalink/catalogue2199
Year of Publication
2019
Topic
Seismic
Material
LVL (Laminated Veneer Lumber)
PSL (Parallel Strand Lumber)
Glulam (Glue-Laminated Timber)
MPP (Mass Plywood Panel)
Application
Wood Building Systems
Author
Murphy, Colton
Pantelides, Chris
Blomgren, Hans-Erik
Rammer, Douglas
Year of Publication
2019
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
PSL (Parallel Strand Lumber)
Glulam (Glue-Laminated Timber)
MPP (Mass Plywood Panel)
Application
Wood Building Systems
Topic
Seismic
Keywords
Lateral Force Resisting System
Buckling Restrained Brace Frames
Conference
INTER
Research Status
Complete
Summary
Buckling Restrained Brace Frames (BRBF) are a proven and reliable method to provide an efficient lateral force resisting system for new and existing structures in earthquake prone regions. The fuse-type elements in this system facilitate stable energy dissipation at large load deformation levels. Currently, the new trend towards mass timber vertical...
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Free
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Development of Timber Buckling Restrained Braces for Mass Timber Braced Frames

https://research.thinkwood.com/en/permalink/catalogue2544
Year of Publication
2019
Topic
Seismic
Design and Systems
Application
Frames
Author
Murphy, Colton
Pantelides, Chris
Blomgren, Hans-Erik
Rammer, Douglas
Year of Publication
2019
Format
Conference Paper
Application
Frames
Topic
Seismic
Design and Systems
Keywords
Brace
Buckling
Damping
Fuse
Seismic
Structure
Timber
Conference
International Network on Timber Engineering Research
Research Status
Complete
Summary
Buckling Restrained Brace Frames (BRBF) are a proven and reliable method to provide an efficient lateral force resisting system for new and existing structures in earthquake prone regions. The fuse-type elements in this system facilitate stable energy dissipation at large load deformation levels. Currently, the new trend towards mass timber vertical structures creates a need for a lightweight compatible lateral force resisting system. A Buckling Restrained Brace (BRB) component is possible to construct and feasible to implement when combining a steel core with a mass timber casing herein named the Timber-Buckling Restrained Brace (T-BRB). T-BRBs when combined with mass timber beam and column elements can create a system that will have advantages over the current steel framed BRBF system when considering recyclability, sustainability, framing compatibility, and performance. This paper presents findings on small scale testing of candidate engineered wood products for the T-BRB casing and testing of six full scale 12 ft long 60 kip braces according to code prescribed loading protocols and acceptance criteria.
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24 records – page 1 of 3.