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10 records – page 1 of 1.

100-Year Performance of Timber-Concrete Composite Bridges in the United States

https://research.thinkwood.com/en/permalink/catalogue2561
Year of Publication
2020
Topic
Serviceability
Application
Bridges and Spans
Author
Wacker, James
Dias, Alfredo
Hosteng, Travis
Year of Publication
2020
Country of Publication
United States
Format
Journal Article
Application
Bridges and Spans
Topic
Serviceability
Keywords
Concrete
Composite
Superstructure
Performance
Inspection
Language
English
Research Status
Complete
Series
Journal of Bridge Engineering
Summary
The use of timber–concrete composite (TCC) bridges in the United States dates back to approximately 1924 when the first bridge was constructed. Since then a large number of bridges have been built, of which more than 1,400 remain in service. The oldest bridges still in service are now more than 84 years old and predominately consist of two different TCC systems. The first system is a slab-type system that includes a longitudinal nail-laminated deck composite with a concrete deck top layer. The second system is a stringer system that includes either sawn timber or glulam stringers supporting a concrete deck top layer. The records indicate that most of the TCC highway bridges were constructed during the period of 1930–1960. The study presented in this paper discusses the experience and per-formance of these bridge systems in the US. The analysis is based on a review of the relevant literature and databases complemented with field inspections conducted within various research projects. Along with this review, a historical overview of the codes and guidelines available for the design of TCC bridges in the US is also included. The analysis undertaken showed that TCC bridges are an effective and durable design alternative for highway bridges once they have shown a high performance level, in some situations after more than 80 years in service with a low maintenance level.
Online Access
Free
Resource Link
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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
Country of Publication
United States
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
Language
English
Research Status
Complete
Series
Wood and Fiber Science. 50(1): 44-54.
Online Access
Free
Resource Link
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Accommodating Shrinkage in Multi-Story Wood-Frame Structures

https://research.thinkwood.com/en/permalink/catalogue712
Year of Publication
2017
Topic
Design and Systems
Moisture
Material
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Author
McLain, Richard
Steimle, Doug
Organization
WoodWorks
Year of Publication
2017
Country of Publication
United States
Format
Report
Material
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Topic
Design and Systems
Moisture
Keywords
Shrinkage
Mid-Rise
Multi-Story
Moisture Content
Language
English
Research Status
Complete
Summary
In wood-frame buildings of three or more stories, cumulative shrinkage can be significant and have an impact on the function and performance of finishes, openings, mechanical/electrical/plumbing (MEP) systems, and structural connections. However, as more designers look to wood-frame construction to improve the cost and sustainability of their mid-rise projects, many have learned that accommodating wood shrinkage is actually very straightforward. This publication will describe procedures for estimating wood shrinkage and provide detailing options that minimize its effects on building performance.
Online Access
Free
Resource Link
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Achieving Sustainable Urban Buildings with Seismically Resilient Mass Timber Core Wall and Floor System

https://research.thinkwood.com/en/permalink/catalogue2802
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Cores
Walls
Floors
Wood Building Systems
Organization
Portland State University
Country of Publication
United States
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Cores
Walls
Floors
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Hold-Down
Seismic Performance
Core Walls
Parametric Analysis
Deformation Capacity
Overstrength
Mid-Rise
High-Rise
Tall Wood Buildings
Research Status
In Progress
Notes
Project contact is Peter Dusicka at Portland State University
Summary
The urgency in increasing growth in densely populated urban areas, reducing the carbon footprint of new buildings, and targeting rapid return to occupancy following disastrous earthquakes has created a need to reexamine the structural systems of mid- to high-rise buildings. To address these sustainability and seismic resiliency needs, the objective of this research is to enable an all-timber material system in a way that will include architectural as well as structural considerations. Utilization of mass timber is societally important in providing buildings that store, instead of generate, carbon and increase the economic opportunity for depressed timber-producing regions of the country. This research will focus on buildings with core walls because those building types are some of the most common for contemporary urban mid- to high-rise construction. The open floor layout will allow for commercial and mixed-use occupancies, but also will contain significant technical knowledge gaps hindering their implementation with mass timber. The research plan has been formulated to fill these gaps by: (1) developing suitable mid- to high-rise archetypes with input from multiple stakeholders, (2) conducting parametric system-level seismic performance investigations, (3) developing new critical components, (4) validating the performance with large-scale experimentation, and (5) bridging the industry information gaps by incorporating teaching modules within an existing educational and outreach framework. Situated in the heart of a timber-producing region, the multi-disciplinary team will utilize the local design professional community with timber experience and Portland State University's recently implemented Green Building Scholars program to deliver technical outcomes that directly impact the surrounding environment. Research outcomes will advance knowledge at the system performance level as well as at the critical component level. The investigated building system will incorporate cross laminated timber cores, floors, and glulam structural members. Using mass timber will present challenges in effectively achieving the goal of desirable seismic performance, especially seismic resiliency. These challenges will be addressed at the system level by a unique combination of core rocking combined with beam and floor interaction to achieve non-linear elastic behavior. This system behavior will eliminate the need for post-tensioning to achieve re-centering, but will introduce new parameters that can directly influence the lateral behavior. This research will study the effects of these parameters on the overall building behavior and will develop a methodology in which designers could use these parameters to strategically control the building seismic response. These key parameters will be investigated using parametric numerical analyses as well as large-scale, sub-system experimentation. One of the critical components of the system will be the hold-down, a device that connects the timber core to the foundation and provides hysteretic energy dissipation. Strength requirements and deformation demands in mid- to high-rise buildings, along with integration with mass timber, will necessitate the advancement of knowledge in developing this low-damage component. The investigated hold-down will have large deformation capability with readily replaceable parts. Moreover, the hold-down will have the potential to reduce strength of the component in a controlled and repeatable way at large deformations, while maintaining original strength at low deformations. This component characteristic can reduce the overall system overstrength, which in turn will have beneficial economic implications. Reducing the carbon footprint of new construction, linking rural and urban economies, and increasing the longevity of buildings in seismic zones are all goals that this mass timber research will advance and will be critical to the sustainable development of cities moving forward.
Resource Link
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Acoustical Guide: Acoustic Research Report on Mass Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1839
Year of Publication
2018
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Other Materials
Application
Floors

Acoustically-Tested Mass Timber Assemblies

https://research.thinkwood.com/en/permalink/catalogue2639
Year of Publication
2020
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
NLT (Nail-Laminated Timber)
Glulam (Glue-Laminated Timber)
MPP (Mass Plywood Panel)
Application
Floors
Walls

Acoustical Performance of Mass Timber Building Elements

https://research.thinkwood.com/en/permalink/catalogue2553
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
NLT (Nail-Laminated Timber)
Application
Floors
Walls
Country of Publication
Canada
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
NLT (Nail-Laminated Timber)
Application
Floors
Walls
Topic
Acoustics and Vibration
Keywords
Sound Insulation
Acoustic Membrane
Acoustical Performance
Research Status
In Progress
Notes
Project contact is Jianhui Zhou at the University of Northern British Columbia
Summary
Building acoustics has been identified as one of the key subjects for the success of mass timber in the multi-storey building markets. The project will investigate the acoustical performance of mass timber panels produced in British Columbia. The apparent sound transmission class (ASTC) and impact insulation class (AIIC) of bare mass timber elements as wall and/ or floor elements will be measured through a lab mock-up. It is expected that a database of the sound insulation performance of British Columbia mass timber products will be developed with guidance on optimal acoustical treatments to achieve different levels of performance.
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Acoustic Characteristics of Cross-Laminated Timber Systems

https://research.thinkwood.com/en/permalink/catalogue2618
Year of Publication
2020
Topic
Acoustics and Vibration
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Di Bella, Antonino
Mitrovic, Milica
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Design and Systems
Keywords
Wooden Building Technology
Building Acoustics
Noise Control
Flanking Transmission
Energy Efficiency
Sustainability
Language
English
Research Status
Complete
Series
Sustainability
Summary
The growing diffusion of cross-laminated timber structures (CLT) has been accompanied by extensive research on the peculiar characteristics of this construction system, mainly concerning its economic and environmental benefits, lifecycle, structural design, resistance to seismic actions, fire protection, and energy efficiency. Nevertheless, some aspects have not yet been fully analysed. These include both the knowledge of noise protection that CLT systems are able to offer in relation to the possible applications and combinations of building elements, and the definition of calculation methods necessary to support the acoustic design. This review focuses on the main acoustic features of CLT systems and investigate on the results of the most relevant research aimed to provide key information on the application of acoustic modelling in CLT buildings. The vibro-acoustic behaviour of the basic component of this system and their interaction through the joints has been addressed, as well as the possible ways to manage acoustic information for calculation accuracy improvement by calibration with data from on-site measurements during the construction phase. This study further suggests the opportunity to improve measurement standards with specific reference curves for the bare CLT building elements, in order to compare different acoustic linings and assemblies on the same base. In addition, this study allows to identify some topics in the literature that are not yet fully clarified, providing some insights on possible future developments in research and for the optimization of these products.
Online Access
Free
Resource Link
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Acoustic Emission of Bolt-Bearing Testing on Structural Composite Lumbers

https://research.thinkwood.com/en/permalink/catalogue1443
Year of Publication
2014
Topic
Acoustics and Vibration
Material
LVL (Laminated Veneer Lumber)
OSL (Oriented Strand Lumber)
Author
Du, Yicheng
Zhang, Jilei
Shi, Sheldon
Publisher
Society of Wood Science and Technology
Year of Publication
2014
Country of Publication
United States
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
OSL (Oriented Strand Lumber)
Topic
Acoustics and Vibration
Keywords
Acoustic Emission
Bolted Connection
Language
English
Research Status
Complete
Series
Wood and Fiber Science
Summary
Acoustic emission (AE) characteristics of full-hole bolt-bearing testing on structural compositelumbers (SCL) including laminated veneer lumber (LVL) and oriented strand lumber (OSL) were investigated. The main conclusion is that AE cumulative counts vs time curves of the tested SCL in this study can be characterized with three distinct regions in terms of AE count rates: Region I with a lower constant count rate, Region II with varied and increased count rates, and Region III with a higher constant count rate. Differences in AE count rates of these three regions occurred between LVL and OSL. Also, within each tested SCL, differences in AE count rates were observed among the three regions. These differences in terms of AE count rates between two tested SCL indicate that different types of wood-based composites might have different AE characteristics in terms of the count rate changes when they are subjected to increased bolt compression load. In other words, these differences in AE characteristics between the two tested materials suggest AE “signatures” do exist for SCL bolt connections.
Online Access
Free
Resource Link
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Acoustic Impact Testing and Waveform Analysis for Damage Detection in Glued Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue771
Year of Publication
2017
Topic
Acoustics and Vibration
Serviceability
Material
Glulam (Glue-Laminated Timber)
Author
Xu, Feng
Wang, Xiping
Teder, Marko
Liu, Yunfei
Publisher
De Gruyter
Year of Publication
2017
Country of Publication
Germany
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Acoustics and Vibration
Serviceability
Keywords
Decay
Delamination
Damage Detection
Moment Analysis
Wavelet Transform
Acoustic Signals
Language
English
Research Status
Complete
Series
Holzforschung
ISSN
1437-434X
Summary
Delamination and decay are common structural defects in old glued laminated timber (glulam) buildings, which, if left undetected, could cause severe structural damage. This paper presents a new damage detection method for glulam inspection based on moment analysis and wavelet transform (WT) of impact acoustic signals. Acoustic signals were collected from a glulam arch section removed from service through impact testing at various locations. The presence and positions of internal defects were preliminarily determined by applying time centroid and frequency centroid of the first moment. Acoustic signals were then decomposed by wavelet packet transform (WPT) and the energy of the sub-bands was calculated as characteristics of the response signals. The sub-bands of 0–375 Hz and 375–750 Hz were identified as the most discriminative features that are associated with decay and delamination and therefore are indicative of the presence of delamination or decay defects. A defect diagnosis algorithm was tested for its ability to identify internal decay and delamination in glulam. The results show that depth of delamination in a glulam member can be determined with reasonable accuracy.
Online Access
Free
Resource Link
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10 records – page 1 of 1.