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8 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.
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Bridge Deterioration Quantification Protocol Using UAV

https://research.thinkwood.com/en/permalink/catalogue1966
Year of Publication
2018
Topic
Serviceability
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Author
Duque, Luis
Seo, Junwon
Wacker, James
Publisher
American Society of Civil Engineers
Year of Publication
2018
Country of Publication
United States
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Topic
Serviceability
Keywords
Bridge
Unmanned Aerial Vehicle
UAV
Photogrammetry
Damage
Field Measurements
Pixel
Language
English
Research Status
Complete
Series
Journal of Bridge Engineering
Summary
This paper focuses on evaluating the effectiveness of an unmanned aerial vehicle (UAV) as a supplementary bridge damage quantification tool. For this study, a glued-laminated timber arch bridge in South Dakota was selected, and an UAV was utilized for the bridge damage quantification. A recommended four-stage UAV-enabled bridge damage quantification protocol involving image quality assessment and image-based damage quantification was developed...
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Development of a Smart Timber Bridge (Phase III): Moisture and Strain Sensor Investigation for Historic Covered Bridges

https://research.thinkwood.com/en/permalink/catalogue2182
Year of Publication
2019
Topic
Moisture
Material
Glulam (Glue-Laminated Timber)
Other Materials
Application
Bridges and Spans
Author
Phares, Brent
Pence, Trevor
Wacker, James
Hosteng, Travis
Year of Publication
2019
Country of Publication
United States
Format
Report
Material
Glulam (Glue-Laminated Timber)
Other Materials
Application
Bridges and Spans
Topic
Moisture
Keywords
Moisture Content
Sensor
Strain
Reliability
Accuracy
Language
English
Research Status
Complete
Series
General Technical Report
Summary
Nationwide, bridges are deteriorating at a rate faster than they can be rehabilitated and maintained. This has resulted in a search for new methods to rehabilitate, repair, manage, and construct bridges. As a result, structural health monitoring and smart structure concepts have emerged to help improve bridge management. In the case of timber bridges, however, a limited amount of research as been conducted on long-term structural health monitoring solutions, and this is especially true in regards to historic covered timber bridges. To date, evaluation efforts of timber bridges have focused primarily on visual inspection data to determine the structural integrity of timber structures. To fill this research need and help improve timber bridge inspection and management strategies, a 5-year research plan to develop a smart timber bridge structure was undertaken. The overall goal of the 5-year plan was to develop a turnkey system to analyze, monitor, and report on the performance and condition of timber bridges. This report outlines one phase of the 5-year research plan and focuses on developing and attaching moisture sensors onto timber bridge components. The goal was to investigate the potential for sensor technologies to reliably monitor the in situ moisture content of the timber members in historic covered bridges, especially those recently rehabilitated with glulam materials. The timber-specific moisture sensors detailed in this report and the data collected from them will assist in advancing the smart timber bridge.
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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 timbe...
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Evaluating the Use of Drones for Timber Bridge Inspection

https://research.thinkwood.com/en/permalink/catalogue1835
Year of Publication
2018
Topic
General Information

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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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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8 records – page 1 of 1.