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138 records – page 1 of 14.

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
Material
Timber-Concrete Composite
Application
Bridges and Spans
Author
Wacker, James
Dias, Alfredo
Hosteng, Travis
Organization
Forest Products Laboratory
Year of Publication
2020
Format
Journal Article
Material
Timber-Concrete Composite
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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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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Adhesive-Bonded Timber-Concrete Composites - Experimental Investigation of Thermal-Hygric Effects

https://research.thinkwood.com/en/permalink/catalogue1519
Year of Publication
2016
Topic
Serviceability
Mechanical Properties
Material
Timber-Concrete Composite
Author
Seim, Werner
Eisenhut, Lars
Kühlborn, Sonja
Year of Publication
2016
Format
Conference Paper
Material
Timber-Concrete Composite
Topic
Serviceability
Mechanical Properties
Keywords
Climate
Long-term
Shear Strength
Deformation
Temperature
Moisture Content
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 597-605
Summary
The advantages of the two different building construction materials, timber and concrete, can be used effectively in adhesive-bonded timber-concrete composite constructions. The long-term behavior was investigated experimentally on small-scale shear and bond specimens under artificial, alternating climatic conditions and on fullscale specimens under natural climatic conditions for an application in construction practice. The development of the shear strength and the deformation behavior under permanent loads were studied, focusing on the different material behavior of wood and concrete regarding changes in temperature and moisture. The general applicability of adhesivebonded timber-concrete composites in construction practice was proved in the investigations.
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Adhesive Bonding of Structural Hardwood Elements

https://research.thinkwood.com/en/permalink/catalogue75
Year of Publication
2015
Topic
Mechanical Properties
Serviceability
Moisture
Material
Glulam (Glue-Laminated Timber)
CLT (Cross-Laminated Timber)
Author
Hassani, Mohammad
Organization
ETH Zurich
Year of Publication
2015
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Serviceability
Moisture
Keywords
Abaqus
Adhesives
Beech
Bonding
Delamination
Finite Element Model
Fracture
Long-term
Model
Hardwood
Research Status
Complete
Summary
The current research investigated the delamination process of adhesively bonded hardwood (European beech) elements subject to changing climatic conditions. For the study of the long-term fracture mechanical behavior of gluedlaminated components under varying moisture content, the role of moisture development, time- and moisture-dependent responses are absolutely crucial. For this purpose, a 3D orthotropic hygro-elastic, plastic, visco-elastic, mechano-sorptive wood constitutive model with moisture-dependent material constants was presented in this work. Such a comprehensive material model is capable to capture the true historydependent stress states and deformations which are essential to achieve reliable design of timber structures. Besides the solid wood substrates, the adhesive material also influences the interface performance considerably. Hence, to gain further insight into the stresses and deformations generated in the bond-line, a general hygro-elastic, plastic, visco-elastic creep material model for adhesive was introduced as well. The associated numerical algorithms developed on the basis of additive decomposition of the total strain were formulated and implemented within the Abaqus Finite Element (FE) package. Functionality and performance of the proposed approach were evaluated by performing multiple verification simulations of wood components, under different combinations of mechanical loading and moisture variation. Moreover, the generality and efficiency of the presented approach was further demonstrated by conducting an application example of a hybrid wood element.
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Adhesive Bonding of Timber and Glass in Load-Bearing Facades - Evaluation of the Ageing Behaviour

https://research.thinkwood.com/en/permalink/catalogue1742
Year of Publication
2016
Topic
Connections
Serviceability
Material
Timber-Glass Composite
Application
Hybrid Building Systems
Author
Nicklisch, Felix
Weller, Bernhard
Year of Publication
2016
Format
Conference Paper
Material
Timber-Glass Composite
Application
Hybrid Building Systems
Topic
Connections
Serviceability
Keywords
Adhesives
Façade
Load Bearing
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4913-4920
Summary
Wooden constructions are on the rise again – encouraged by a strong trend towards sustainable and resource efficient buildings. Load-bearing timber-glass composite elements – a novel concept to use the in-plane loadbearing potential of glass – could contribute to a more efficient use of materials in façades. The current study relates to the adhesive bond between the glass pane and the timber substructure. The applicability of structural sealants such as silicones is limited due to their distinct flexibility which leads to large deformations of the joint. Further potential arises from the use of adhesives of medium and high stiffness. Their general performance as well as their durability have not yet been evaluated with respect to the proposed use in building constructions. This paper draws attention to the ageing stability of two promising adhesives. Small-scale adhesively bonded specimens which are composed of a wooden and a glass piece are exposed to different ageing scenarios which relate to the impacts typically encountered in façades. Based on the results it can be concluded that the considered high-modules adhesives enable an increase of characteristic failure loads and a reduction of joint deformation, but also reveal shortcomings regarding their ageing stability.
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Advanced Wood-Based Solutions for Mid-Rise and High-Rise Construction: In-Situ Testing of the Origine 13-Storey Building for Vibration and Acoustic Performances

https://research.thinkwood.com/en/permalink/catalogue1474
Year of Publication
2018
Topic
Acoustics and Vibration
Serviceability
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Floors
Walls
Author
Hu, Lin
Cuerrier-Auclair, Samuel
Organization
FPInnovations
Year of Publication
2018
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Floors
Walls
Topic
Acoustics and Vibration
Serviceability
Keywords
Origine
Natural Frequencies
Damping Ratios
Sound Insulation
Ambient Vibration Tests
Static Deflection
Apparent Sound Transmission Class
Apparent Impact Insulation Class
Research Status
Complete
Summary
Serviceability performance studied covers three different performance attributes of a building. These attributes are 1) vibration of the whole building structure, 2) vibration of the floor system, typically in regards to motions in a localized area within the entire floor plate, and 3) sound insulation performance of the wall and floor assemblies. Serviceability performance of a building is important as it affects the comfort of its occupants and the functionality of sensitive equipment as well. Many physical factors influence these performances. Designers use various parameters to account for them in their designs and different criteria to manage these performances. Lack of data, knowledge and experience of sound and vibration performance of tall wood buildings is one of the issues related to design and construction of tall wood buildings. In order to bridge the gaps in the data, knowledge, and experience of sound and vibration performance of tall wood buildings, FPInnovations conducted a three-phase performance testing on the Origine 13-storey CLT building of 40.9 m tall in Quebec city. It was the tallest wood building in Eastern Canada in 2017.
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Ambient Vibration Testing and Modal Analysis of Multi-Storey Cross Laminated Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue237
Year of Publication
2014
Topic
Acoustics and Vibration
Wind
Serviceability
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Reynolds, Thomas
Bolmsvik, Åsa
Vessby, Johan
Chang, Wen-Shao
Harris, Richard
Bawcombe, Jonathan
Bregulla, Julie
Year of Publication
2014
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Wind
Serviceability
Keywords
Modal Properties
Multi-Storey
Damping
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The ambient movement of three modern multi-storey timber buildings has been measured and used to determine modal properties. This information, obtained by a simple, unobtrusive series of tests, can give insights into the structural performance of these forms of building, as well as providing information for the design of future, taller timber buildings for dynamic loads. For two of the buildings, the natural frequency has been related to the lateral stiffness of the structure, and compared with that given by a simple calculation. In future tall timber buildings, a new design criterion is expected to become important: deflection and vibration serviceability under wind load. For multi-storey timber buildings there is currently no empirical basis to estimate damping for calculation of wind-induced vibration, and there is little information for stiffness under wind load. This study therefore presents a method to address those gaps in knowledge.
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An Enhanced Beam Model for Glued Laminated Structures that takes Moisture, Mechano-sorption and Time Effects into Account

https://research.thinkwood.com/en/permalink/catalogue44
Year of Publication
2014
Topic
Moisture
Serviceability
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Ormarsson, Sigurdur
Steinnes, Jan
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Moisture
Serviceability
Keywords
Climate
Creep
Finite Element Model
Hygro-Mechanical
Long-term
Visco-Elastic
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
There is a need of more advanced analysis for studying how the long-term behaviour of glued laminated timber structures is affected by creep and by cyclic variations in climate. A beam theory is presented able to simulate the overall hygro-mechanical and visco-elastic behaviour of (inhomogeneous) glulam structures. Two frame structures subjected to both mechanical and cyclic environmental loading are analysed to illustrate the advantages the model involved can provide. The results indicate clearly both the (discontinuous) inhomogeneity of the glulam products and the variable moisture-load action that occurs to have a significant effect on deformations, section forces and stress distributions within the frame structures that were studied.
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Assessment of effect of climate change on hygrothermal performance of cross-laminated timber building envelope with modular construction

https://research.thinkwood.com/en/permalink/catalogue2890
Year of Publication
2021
Topic
Moisture
Serviceability
Material
CLT (Cross-Laminated Timber)
Application
Building Envelope
Author
Chang, Seong Jin
Kang, Yujin
Yun, Beom Yeol
Yang, Sungwoong
Kim, Sumin
Organization
Gyeongsang National University
Yonsei University
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Building Envelope
Topic
Moisture
Serviceability
Keywords
Climate Change
Modular Construction
Hygrothermal Performance
Mock-up Experiments
Research Status
Complete
Series
Case Studies in Thermal Engineering
Summary
Cross-laminated timber (CLT) modular construction possesses the advantages of wood, such as excellent carbon storage and thermal insulation, and of modular construction, such as considerably reduced construction period and cost as well as high productivity. This study evaluates the hygrothermal performance of CLT walls considering modular construction in future climatic conditions. Firstly, CLT walls with plywood applied to a core layer were manufactured. A mock-up of a CLT building was produced and its construction process was analyzed. Hygrothermal behavior of the CLT walls was simulated using WUFI simulation program, and the predicted results were verified against measurements obtained from the mock-up experiment. Finally, the hygrothermal performance of the CLT wall was evaluated for four types of insulation and future climate in eight cities of USA. The coefficient of variation—root mean square error (CV(RMSE))—of the temperature and relative humidity inside the ply-lam CLT wall from mock-up experiments and simulation evaluation were 6.43% and 7.02%, respectively, which met the validation criteria. Based on the hygrothermal performance, the ply-lam CLT wall with extruded polystyrene insulation was evaluated as safe from moisture problems in all the eight cities considered in this study. However, the risk of mold growth in all regions and insulation types increased under climate change with a rise of average annual temperature.
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Assessment of Structural Performance of Accoya® Wood for Glulam Fabrication

https://research.thinkwood.com/en/permalink/catalogue1199
Year of Publication
2012
Topic
Mechanical Properties
Serviceability
Material
Glulam (Glue-Laminated Timber)
Author
Crawford, David
Hairstans, Robert
Alexander, John
Bongers, Ferry
Year of Publication
2012
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Serviceability
Keywords
Durability
Long-term Performance
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
July 15-19, 2012, Auckland, New Zealand
Summary
Accoya® GluLam beams were specified for use as an external foundation support detail for an innovative low carbon affordable home in the Scottish Highlands. This detail was identified in collaboration with Neil Sutherland Architects (NSA) LLP where the use of Accoya® GluLam would result in enhanced performance in exposed conditions. The Accoya® GluLam provides support to the superstructure formed from offsite fabricated closed panels therefore reduced movement over time due to moisture fluctuations was identified as a key design consideration in order to ensure serviceability criteria are met. Due to the nature of Accoya® (acetylated timber) a test programme was developed to determine its mechanical properties for specification as a structural component both in isolation and in combination. In order to assess the long term performance of acetylated GluLam a number of beams are currently being monitored using in-situ monitoring equipment over a minimum period of 12 months.
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138 records – page 1 of 14.