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692 records – page 1 of 70.

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
Format
Journal Article
Application
Bridges and Spans
Topic
Serviceability
Keywords
Concrete
Composite
Superstructure
Performance
Inspection
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.
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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
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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Accommodating Movement in High-Rise Wood-Frame Building Construction

https://research.thinkwood.com/en/permalink/catalogue1875
Year of Publication
2011
Topic
Design and Systems
Connections
Material
Steel-Timber Composite
Other Materials
LVL (Laminated Veneer Lumber)
Application
Wood Building Systems
Floors
Walls
Author
Howe, Richard
Publisher
Forest Products Society
Year of Publication
2011
Format
Journal Article
Material
Steel-Timber Composite
Other Materials
LVL (Laminated Veneer Lumber)
Application
Wood Building Systems
Floors
Walls
Topic
Design and Systems
Connections
Keywords
Detailing
Shrinkage
Differential Movement
Research Status
Complete
Series
Wood Design Focus
Summary
Ease of construction and favorable overall costs relative to other construction types are making high-rise (i.e., 4- and 5-story) wood frame construction increasingly popular. With these buildings increasing in height, there is a greater impetus on designers to address frame and finishes movement in such construction. As we all know, buildings are dynamic creatures experiencing a variety of movements during construction and over their service life. In wood frame construction, it is important to consider not only absolute movement but also differential movement between dissimilar materials. This article focuses on differential movement issues and how to recognize their potential and avoid problems by effective detailing.
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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
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.
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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
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
OSL (Oriented Strand Lumber)
Topic
Acoustics and Vibration
Keywords
Acoustic Emission
Bolted Connection
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.
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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
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Acoustics and Vibration
Serviceability
Keywords
Decay
Delamination
Damage Detection
Moment Analysis
Wavelet Transform
Acoustic Signals
Research Status
Complete
Series
Holzforschung
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.
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Adoption of Unconventional Approaches in Construction: The Case of Cross-Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue1358
Year of Publication
2016
Topic
Market and Adoption
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Jones, Kell
Stegemann, Julia
Sykes, Judith
Winslow, Peter
Publisher
ScienceDirect
Year of Publication
2016
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Market and Adoption
Keywords
United Kingdom
Construction
Research Status
Complete
Series
Construction and Building Materials
Summary
Achieving sustainable development requires the decoupling of economic growth from the use of non-renewable resources. This depends on industry adopting unconventional approaches to production. This research explores the root causes of barriers to the adoption of such approaches in the construction industry, and applies a behavioural model to assess whether companies are hindered by capability, opportunity or motivation. The long history of lowest-cost tendering in construction has led to a path-dependent lock-in to conventional market-driven objectives of cost and risk reduction; it is suggested that locked-in companies lack the commercial opportunity and hence motivation, rather than the capability, to adopt approaches perceived to increase cost or risk. Such companies will therefore tend to resist unconventional approaches, restricting the physical opportunity for other project participants. This theory is explored in a case study of first adoptions of cross-laminated timber (CLT) in UK projects, using a survey and series of semi-structured interviews. The case study found that project contexts created market niches. This provided designers, who were motivated to use CLT, the opportunity to promote its use in the project. CLT was seen as key to successful resolution of project constraints, thereby providing motivation to other project participants to adopt the material.
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Advanced Timber Construction Industry: A Review of 350 Multi-Storey Timber Projects from 2000–2021

https://research.thinkwood.com/en/permalink/catalogue3006
Year of Publication
2022
Topic
Market and Adoption
Application
Wood Building Systems
Author
Svatoš-Ražnjevic, Hana
Orozco, Luis
Menges, Achim
Organization
University of Stuttgart
Editor
Brandner, Reinhard
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Application
Wood Building Systems
Topic
Market and Adoption
Keywords
Multi-storey Timber Construction
Timber Buildings
Mass Timber Construction
Survey
Typologies
Trends and Perspectives
Timber Morphologies
Research Status
Complete
Series
Buildings
Summary
Throughout the last two decades the timber building sector has experienced a steady growth in multi-storey construction. Although there has been a growing number of research focused on trends, benefits, and disadvantages in timber construction from various technical perspectives, so far there is no extensive literature on the trajectory of emerging architectural typologies. This paper presents an examination of architectural variety and spatial possibilities in current serial and modular multi-storey timber construction. It aims to draw a parallel between architectural characteristics and their relation to structural systems in timber. The research draws from a collection of 350 contemporary multi-storey timber building projects between 2000 and 2021. It consists of 300 built projects, 12 projects currently in construction, and 38 design proposals. The survey consists of quantitative and qualitative project data, as well as classification of the structural system, material, program, massing, and spatial organization of the projects. It then compares the different structural and design aspects to achieve a comprehensive overview of possibilities in timber construction. The outcome is an identification of the range of morphologies and a better understanding of the design space in current serial and modular multi-storey mass timber construction.
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Airborne and impact sound performance of modern lightweight timber buildings in the Australian construction industry

https://research.thinkwood.com/en/permalink/catalogue2948
Year of Publication
2021
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Jayalath, Amitha
Navaratnam, Satheeskumar
Gunawardena, Tharaka
Mendis, Priyan
Aye, Lu
Organization
The University of Melbourne
RMIT University
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Impact Sound Transmission
Airborne Sound Transmission
Simulation
Research Status
Complete
Series
Case Studies in Construction Materials
Summary
Timber usage in the Australian construction industry has significantly increased due to its strength, aesthetic properties and extended allowances recently introduced in building codes. However, issues with acoustic performance of lightweight timber buildings were reported due to their inherit product variability and varying construction methods. This article reviews the recent literature on the transmissions of impact and airborne sounds, flanking transmission of timber buildings, and the state of computer prediction tools with reference to the Australian practice. An in-depth analysis of issues and an objective discussion related to acoustic performance of timber buildings are presented. Timber is a lightweight material and shows low airborne sound resistance in low frequency range. Attenuation of sound transmission with addition of mass, layer isolation, different products like cross-laminated timber and prefabrication are discussed. Challenges in measuring sound transmissions and reproducibility of results in low frequency ranges are discussed. Well-defined measurement protocols and refined computer simulation methods are required. The serviceability design criteria for modern lightweight timber applications in Australia need to be re-evaluated in the area of impact generated sound. Developing computer tools to predict airborne and impact sound transmission in lightweight timber buildings is quite challenging as several components such as timber members and complex connections with varying stiffnesses are non-homogeneous by nature. Further, there is a lack of experimentally validated and computationally efficient tools to predict the sound transmission in timber buildings. Computer prediction tools need to be developed with a focus on mid-frequency transmission over flanks and low-frequency transmission of timber and prefabricated buildings.
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Ambient Vibration Measurement Data of a Four-Story Mass Timber Building

https://research.thinkwood.com/en/permalink/catalogue2211
Year of Publication
2019
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems

692 records – page 1 of 70.