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11 records – page 1 of 2.

Dynamic Response of an Under-Deck Cable-Stayed Timber-Concrete Composite Bridge Under a Moving Load

https://research.thinkwood.com/en/permalink/catalogue2037
Year of Publication
2018
Topic
Mechanical Properties
Design and Systems
Material
Timber-Concrete Composite
Application
Bridges and Spans

Effectiveness of Several NDE Technologies in Detecting Moisture Pockets and: Artificial Defects in Sawn Timber and Glulam

https://research.thinkwood.com/en/permalink/catalogue778
Year of Publication
2016
Topic
Serviceability
Material
Glulam (Glue-Laminated Timber)
Solid-sawn Heavy Timber
Application
Bridges and Spans
Author
Wacker, James
Senalik, Christopher
Wang, Xping
Jalinoos, Frank
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Solid-sawn Heavy Timber
Application
Bridges and Spans
Topic
Serviceability
Keywords
Decay
Douglas-Fir
Moisture Pockets
Non-Destructive Evaluation
Scanning
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria
Summary
Several nondestructive evaluation (NDE) technologies were studied to determine their efficacy as scanning devices to detect internal moisture and artificial decay pockets. Large bridge-sized test specimens, including sawn timber and glued-laminated timber members, were fabricated with various internal defects. NDE Technologies evaluated in this research were ground penetrating radar (GPR), microwave scanning, ultrasonic pulse velocity, ultrasonic shear wave tomography, and impact echo methods. Each NDE technology was used to evaluate a set of seven test specimens over a 2-day period and then raw data scans were processed into two-dimensional, internal defect maps. Several parameters were, compared including the relative size, orientation, and moisture conditions of the internal defect. GPR was the most promising NDE technology and is currently being more rigorously evaluated within the laboratory. The study results will be useful in the further development of a reliable NDE scanning technique that can be utilized to inspect the primary structural components in historic covered timber bridges.
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Effect of Moisture Induced Stresses on the Mechanical Performance of Glulam Beams of Vihantasalmi Bridge

https://research.thinkwood.com/en/permalink/catalogue1609
Year of Publication
2016
Topic
Moisture
Serviceability
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Author
Hradil, Petr
Fortino, Stefania
Salokangas, Lauri
Musci, Alessandro
Metelli, Giovanni
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Topic
Moisture
Serviceability
Keywords
Moisture Induced Stresses
Finland
Moisture Gradients
Moisture Content
Hygrothermal
Multi-Fickian Theory
Relative Humidity
Temperature
Eurocode 5
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2159-2167
Summary
The present paper deals with the effect of moisture induced stresses (MIS) on the mechanical performance of a glulam beam of Vihantasalmi Bridge in Finland. MIS caused by high moisture gradients in a cross section of the glulam beam are calculated by a hygro-thermal multi-Fickian model for evaluation of moisture content, relative humidity and temperature in wood that is sequentially coupled with an orthotropic-viscoelasticmechanosorptive model for calculation of wood stresses. Both models, already developed in Abaqus FEM code by some of the authors in their previous works, had to be modified for the Nordic climate. The obtained levels of MIS are then compared to the Eurocode 5 design resistances. The study aims at providing suggestions to future developments of Eurocode 5 for the correct evaluation of the influence of moisture content on service life in timber bridge elements.
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Efficient Shear Transfer in Timber-Concrete Composite Bridges by Means of Grouting with Polymer Mortar

https://research.thinkwood.com/en/permalink/catalogue1694
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
Timber-Concrete Composite
Application
Bridges and Spans
Author
Kaestner, Martin
Rautenstrauch, Karl
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Timber-Concrete Composite
Application
Bridges and Spans
Topic
Connections
Mechanical Properties
Keywords
Polymer Mortar
Shear Tests
Bending Tests
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4281-4290
Summary
The performance of timber-concrete composite bridge constructions crucially depends on the design of the joint between concrete deck and timber main girders. In research studies at the Bauhaus-University Weimar, innovative joining techniques based on grouting with highly-filled, tolerance-compensating polymer glue mortars have been developed to improve the shear capacity of this joint significantly. By applying a thin layer of polymer mortar on the top of the wooden main girder a continuous, slip-free connection to the timber can be realized. This layer can be utilized for the embedding of steel plates with welded-on shear studs (stud connectors), so that the joint to the concrete side is ensured by a standardised connection. The steel plates are rigidly anchored in the polymer mortar by adhesive bond and form closure. As an alternative, a slip-free grout-glued connection between concrete and timber can be realized by the glue mortar itself, so that also a continuous connection to the concrete is accessible, whereby manufacturing tolerances can easily be compensated due to the high degree of mineral filling of the polymer mortar. The paper focuses on experimental results of shear and bending tests for the new composite joint configurations.
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Field Performance of Timber Bridges: A National Study

https://research.thinkwood.com/en/permalink/catalogue2127
Year of Publication
2013
Topic
Design and Systems
Serviceability
Application
Bridges and Spans
Author
Brashaw, Brian
Wacker, James
Jalinoos, Frank
Year of Publication
2013
Country of Publication
United States
Format
Conference Paper
Application
Bridges and Spans
Topic
Design and Systems
Serviceability
Keywords
Timber Construction
Inspection
Non-Destructive Evaluation
Service Life
Language
English
Conference
International Conference on Timber Bridges
Research Status
Complete
Online Access
Free
Resource Link
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Identifying Incipient Decay in Douglas-fir Bridge Components using X-Ray Computerized Tomography

https://research.thinkwood.com/en/permalink/catalogue2350
Year of Publication
2019
Topic
Design and Systems
Moisture
Serviceability
Material
Glulam (Glue-Laminated Timber)
Solid-sawn Heavy Timber
Application
Bridges and Spans
Author
Senalik, Christopher
Wacker, James
Wang, Xiping
Wu, Xi
Year of Publication
2019
Country of Publication
United States
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Solid-sawn Heavy Timber
Application
Bridges and Spans
Topic
Design and Systems
Moisture
Serviceability
Keywords
X-ray Computerized Tomography
Wood Timber
Brown Rot Fungus
Incipient Decay
Language
English
Conference
International Nondestructive Testing and Evaluation of Wood Symposium
Research Status
Complete
Summary
In this report, wooden members of sizes typically used in bridge construction are examined using x-ray computerized tomography (CT) to determine the presence of internal decay. This report is part of an overall study in which Douglas-fir (Pseudotsuga menziesii) glue-laminated (glulam) beams and solid sawn timbers were inoculated with brown rot fungus, Fomitopsis pinicola, and exposed to aboveground conditions approximately 25 miles (40 km) north of Gulfport, Mississippi, USA. The goal of the overall study is to develop interior decay within the test specimens and then identify and characterize the decay using a variety of nondestructive testing (NDT) techniques. One NDT technique used is x-ray CT. The pixel brightness (PB) of CT scan images is proportional to the specific gravity (SG) at that location; high SG materials appear brighter whereas low SG materials appear darker. The consumption of wood by fungus decreases the wood SG; however, fungal progression takes place in areas where sufficient moisture is present. The presence of moisture increases wood SG as detected by the CT scan, which masks the effect of the fungal decay, which is a common co-occurrence with many NDT techniques. To identify incipient decay, it is necessary to examine the ring structure both within and outside of the area of moisture. Quantifying the extent of the decay requires correlating the PB to known SG values for both dry wood and wood of varying moisture content. In this report, the relationship between wood SG, moisture content, and PB was quantified.
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Long-term Testing of Prefabricated Timber-Steel-Concrete Ribbed Decks

https://research.thinkwood.com/en/permalink/catalogue2083
Year of Publication
2018
Topic
Serviceability
Material
Steel-Timber Composite
Timber-Concrete Composite
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans

New Bridge Inspection Approach with Joint UAV and DIC System

https://research.thinkwood.com/en/permalink/catalogue2560
Year of Publication
2020
Topic
Serviceability
Application
Bridges and Spans
Author
Jeong, Euiseok
Seo, Junwon
Wacker, James
Year of Publication
2020
Country of Publication
United States
Format
Conference Paper
Application
Bridges and Spans
Topic
Serviceability
Keywords
UAV
DIC
Inspection
Deterioration
Detection
Language
English
Conference
Structures Congress
Research Status
Complete
Summary
This research aims to develop a new bridge inspection approach using unmanned aerial vehicle (UAV) coupled with digital image correlation (DIC) system. The DIC system incorporating UAV images can measure displacements or strains by analyzing patterns of reference and deformed images. As part of this research, a commercially available UAV, DJI Matrice 210, was integrated with the DIC system using a 3D printed mounting plate, and the joint UAV-DIC system was utilized to inspect a timber bridge girder in the Structure Lab. Then, the UAV-DIC system inspected an existing timber slab bridge in Pipestone, Minnesota, but the system was not able to efficiently identify critical damage due to its instability caused by windy conditions. Therefore, only the UAV equipped with a gimbal camera was operated to perform the bridge inspection. A significant number of images from the UAV were used and analyzed through a conventional image analysis algorithm within ImageJ software for damage quantification. The major conclusion from this research was that the UAV-DIC system was only able to detect and quantify damage (i.e., crack) on the considered girder under almost zero ambient wind conditions, and the UAV integrated with the image analysis algorithm was capable of damage identification and quantification for the inspected bridge.
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Performance of Timber-Concrete Portable Bridge with Circular Hollow Section Connectors

https://research.thinkwood.com/en/permalink/catalogue1752
Year of Publication
2016
Topic
Mechanical Properties
Connections
Serviceability
Material
Timber-Concrete Composite
Application
Bridges and Spans
Author
Lacis, Raitis
Ozola, Lilita
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Timber-Concrete Composite
Application
Bridges and Spans
Topic
Mechanical Properties
Connections
Serviceability
Keywords
Prefabricated
Proof-Load Tests
Deflection
Bending Strains
Bending Stresses
Transversal Load Distribution
Dynamic Amplification Factor
Field Measurements
FEM
Circular Hollow Connectors
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4997-5005
Summary
This paper presents the research results of a timber-concrete composite portable bridge according to the tests of full-scale structure. Portable timber-concrete bridges can be used for permanent or temporary locations in rural areas such as forests, agricultural fields, mineral extraction pits, military objects and others. All structural elements of...
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Steien Network Arch Bridge

https://research.thinkwood.com/en/permalink/catalogue2128
Year of Publication
2013
Topic
Design and Systems
Application
Bridges and Spans

11 records – page 1 of 2.