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7 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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Delamination Detection in a 90-Year-Old Glulam Block with Scanning Dry Point-Contact Ultrasound

https://research.thinkwood.com/en/permalink/catalogue114
Year of Publication
2013
Topic
Connections
Material
Glulam (Glue-Laminated Timber)
Author
Neuenschwander, Jürg
Sanabria, Sergio
Schuetz, Philipp
Widmann, Robert
Vogel, Mareike
Publisher
De Gruyter
Year of Publication
2013
Country of Publication
Germany
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Keywords
Bonding
Delamination
Inspection
Non-Destructive Evaluation
Language
English
Research Status
Complete
Series
Holzforschung
ISSN
1437-434X
Summary
Glued laminated timber (glulam) is known in timber constructions since more than 100 years. Glulam members can delaminate due to aging and excessive changes of temperature and humidity. This results in significantly reduced load bearing capability of the affected structural members. This contribution focuses on the ultrasonic point-contact inspection of gluing plane delamination as a nondestructive method. Ultrasonic measurements on a section of a 90-year old roofing glulam member are presented. The results are compared with manual detection and evaluation of delamination with a feeler gauge, with X-ray computed tomography analyses, and with numerical simulations. Appropriate data evaluation of the mechanized ultrasonic results allows the determination of material separation that are deeper than 20 mm in the signature of the surface wave and large-scale delamination ( > 80% of the complete bonding width) in the back-wall echo. Numerical simulations based on the finite-difference time-domain method shed light into the details of the wave propagation and support the experimental findings.
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Free
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Drone-Enabled Bridge Inspection Methodology and Application

https://research.thinkwood.com/en/permalink/catalogue1965
Year of Publication
2018
Topic
Serviceability
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Author
Seo, Junwon
Duque, Luis
Wacker, Jim
Publisher
Elsevier
Year of Publication
2018
Country of Publication
United States
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Topic
Serviceability
Keywords
UAV
Bridge
Inspection Methodology
Damage Identification
Field Application
Girder
Superstructure
Language
English
Research Status
Complete
Series
Automation in Construction
Summary
The field of Civil Engineering has lately gained increasing interest in Unmanned Aerial Vehicles (UAV), commonly referred to as drones. Due to an increase of deteriorating bridges according to the report released by the American Society of Civil Engineers (ASCE), a more efficient and cost-effective alternative for bridge inspection is required. The goal of this paper was to analyze the effectiveness of drones as supplemental bridge inspection tools. In pursuit of this goal, the selected bridge for inspection was a three-span gluedlaminated timber girder with a composite concrete deck located near the city of Keystone in the state of South Dakota (SD)...
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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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Load Testing and Assessment of a Field Demonstration CLT Bridge

https://research.thinkwood.com/en/permalink/catalogue2570
Topic
Serviceability
Market and Adoption
Material
CLT (Cross-Laminated Timber)
Application
Bridges and Spans
Organization
South Dakota State University
Country of Publication
United States
Material
CLT (Cross-Laminated Timber)
Application
Bridges and Spans
Topic
Serviceability
Market and Adoption
Keywords
Field Measurements
Load Testing
Moisture Content
Visual Inspection
Long-term Performance
Research Status
In Progress
Notes
Project contact is Junwon Seo at South Dakota State University
Summary
Cross-Laminated Timber (CLT) has great potential to promote wood products markets in appropriate transportation structures, particularly bridges on low-volume roads such as rural or forest roads. The project’s goals are to perform field load testing and evaluation of a demonstration CLT bridge on the nation’s low-volume roads and evaluate its long-term performance under in-service loads and environmental exposure. The team will pursue these goals through the following research objectives: 1) Design the demonstration CLT bridge system with design details; 2) Fabricate the designed CLT bridge; 3) Install the fabricated CLT bridge on a roadway in Grand Portage National Monument with Western Wood Structures, Wheeler, Cook County in Minnesota and the National Park Service; and 4) Perform load testing to assess performance of the implemented bridge and monitor its moisture content and field performance through visual inspection for its long-term behavior evaluation.
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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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A Visual Assessment of Cross-Laminated Timber Structures in Austria

https://research.thinkwood.com/en/permalink/catalogue2693
Year of Publication
2020
Topic
Serviceability
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Quesada-Pineda, Henry
Smith, Robert
Berger, Guenter
Loferski, Joseph
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Building Inspection
Wood Construction
Water Damage
Austria
Language
English
Research Status
Complete
Series
Bioproducts Business
Summary
Cross-laminated timber (CLT) construction systems have been used commercially for over 20 years, mainly in Western Europe and North America. However, there has not been a report on the current status of CLT buildings. Deterioration of wooden buildings could result from a variety of causes and the life of the structures could be extended if periodic inspections were conducted. This research introduces a visual inspection methodology for assessing deterioration of CLT structures. The inspection methodology was tested in six CLT buildings in Austria. The methodology was proven to be effective in determining the current internal and external condition of the examined CLT structures. The oldest CLT structure inspected dates from 2004. The newest structure inspected was still under construction. The results of the application of the visual inspecting tool show that there was very little damage to the CLT structures. The main causes of damage came from exposure to water on the exterior of the buildings and poor control of humidity and temperature in indoor conditions. Architects who designed the inspected buildings were interviewed to cross validate the results of the visual inspection methodology. In addition, the interviews provided important insights related to the design, construction, and current conditions of the buildings. Furthermore, the architects also provided information regarding the main barriers and drivers that affect CLT construction in Austria.
Online Access
Free
Resource Link
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7 records – page 1 of 1.