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10 records – page 1 of 1.

Monitoring Building Climate and Timber Moisture Gradient in Large-Span Timber Structures

https://research.thinkwood.com/en/permalink/catalogue108
Year of Publication
2014
Topic
Serviceability
Moisture
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Gamper, Andreas
Dietsch, Philipp
Winter, Stefan
Editor
Bettina Franke Steffen Franke
Year of Publication
2014
Country of Publication
Switzerland
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Cracks
Damage
Equilibrium Moisture Content
Internal Climate
Lamellas
Large Span
Long-term
Relative Humidity
Shrinkage
Swelling
Temperature
Language
English
Conference
COST Workshop – Highly Performing Timber Structures: Reliability, Assessment, Monitoring and Strengthening
Research Status
Complete
ISSN
2190-5479
Summary
The evaluation of damages in large-span timber structures indicates that the predominantly observed damage pattern is pronounced cracking in the lamellas of glued-laminated timber elements. A significant proportion of these cracks is attributed to the seasonal and use-related variations of the internal climate within large buildings and the associated inhomogeneous shrinkage and swelling processes in the timber elements. To evaluate the significance of these phenomena, long-term measurements of climatic conditions and timber moisture content were taken within large-span timber structures in buildings of typical construction type and use. These measurements were then used to draw conclusions on the magnitude and time necessary for adjustment of the moisture distribution to changing climatic conditions. A comparison of the results for different types of building use confirms the expected large range of possible climatic conditions in buildings with timber structures. Ranges of equilibrium moisture content representative of the type and use of building were obtained. These ranges can be used in design to condition the timber to the right value of moisture content, in this way reducing the crack formation due to moisture variations. The results of this research also support the development of suitable monitoring systems which could be applied in form of early warning systems on the basis of climate measurements. Based on the results obtained, proposals for the practical implementation of the results are given.
Online Access
Free
Resource Link
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Expanding the Cross-Laminated Timber Market through Building Moisture Monitoring and Improved Modeling

https://research.thinkwood.com/en/permalink/catalogue719
Topic
Serviceability
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Organization
Colorado School of Mines
Forest Products Laboratory
Country of Publication
United States
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Moisture Content
Building Envelope
Climate
Hygrothermal Models
Long-term
Research Status
In Progress
Notes
Project contacts are Shiling Pei (Colorado School of Mines) and Samuel L. Zelinka (Forest Products Laboratory)
Summary
This project will generate three benchmark data sets for multistory CLT building moisture performance in different climate zones. Data will include moisture contents at key wood components and high moisture risk locations throughout the buildings. A relatively simple, but fully validated, numerical model for analyzing similar building moisture performance will be recommended. These results will be useful for structural engineers and architects to accurately consider moisture in their design of mass timber buildings.
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Cross-Laminated Timber Roof Panels at the Promega Corporation Facility: Documenting Installation and Monitoring In-Service Moisture Conditions

https://research.thinkwood.com/en/permalink/catalogue801
Year of Publication
2013
Topic
Serviceability
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Glass, Samuel
Romanin, Jennifer
Schumacher, Jim
Spickler, Kris
Organization
Forest Products Laboratory
Year of Publication
2013
Country of Publication
United States
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Moisture
Temperature
Installation Process
Sensors
Language
English
Research Status
Complete
Summary
The USDA Forest Products Laboratory (FPL) has, for the past two years, been assisting in removing technical barriers to the use of CLT and trying to develop interest in the United States for its utilization. Coincidentally, Promega Corporation, a leader in providing innovative solutions and technical support to the life sciences industry, is currently constructing a new facility in Fitchburg, Wisconsin, that features CLT. This is the first large-scale commercial utilization of CLT in the United States using CLT manufactured in North America. As with any new building system, it is important for the design and construction community to have information on how CLT is installed and how it performs. The objectives of this research are twofold: (1) to document the CLT installation process with photography and video and (2) to install sensors in the CLT panels and collect data on in-service moisture and temperature conditions.
Online Access
Free
Resource Link
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Variations of Moisture Content in Manufacturing CLT-Concrete Composite Slab Using Wet Construction Method

https://research.thinkwood.com/en/permalink/catalogue2732
Year of Publication
2021
Topic
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Author
Song, Yo-Jin
Baek, Seong-Yeob
Lee, In-Hwan
Hong, Soon-Il
Publisher
North Carolina State University
Year of Publication
2021
Country of Publication
United States
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Topic
Moisture
Keywords
Wet Construction Method
Moisture Content
Teak
Composite
Adhesive
Delamination
Language
English
Research Status
Complete
Series
BioResources
Summary
Construction of eco-friendly high-rise buildings using cross-laminated timber (CLT)-concrete composite (CCC) slabs is increasing. CLT and concrete, which are major component materials of the CCC slab, are significantly affected by moisture. In particular, the moisture content of concrete in the production process affects the quality of both materials. In this study, the effects of the wet construction method on CLT and concrete component materials are examined by monitoring the behavior of the CCC slab during curing time (28 d) and by evaluating the quality of the concrete and CLT after curing. When manufacturing the CCC using the wet construction method, moisture penetration from the concrete into the CLT during the curing time is suppressed by the shear bonding between the concrete and the CLT when an adhesive is used. This minimizes the effect of the moisture on both component materials, consequently yielding uniform compressive strength to the concrete after curing and preventing the deterioration of the CLT’s delamination performance. Therefore, the shear bonding method using an adhesive is expected to minimize the quality deterioration observed in concrete and CLT after curing.
Online Access
Free
Resource Link
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Effects of Changes in Moisture Content in Reinforced Glulam Beams

https://research.thinkwood.com/en/permalink/catalogue1173
Year of Publication
2014
Topic
Moisture
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Dietsch, Philipp
Kreuzinger, Heinrich
Winter, Stefan
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Moisture
Mechanical Properties
Keywords
Reinforcement
Threaded Rods
Moisture Induced Stresses
Finite Element Method
Moisture Content
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Reinforcement in glulam beams in form of screws or rods can restrict the free shrinkage or swelling of the wood material. The objective of the project presented was to evaluate the influence of such reinforcement on the magnitude of moisture induced stresses. For this purpose, experimental studies were carried out in combination with analytical considerations on the basis of the finite-element method. Taking into account the influence of relaxation processes, the results indicate that a reduction of timber moisture content of 3 - 4 % around threaded rods, positioned perpendicular to the grain, can lead to critical stresses with respect to moisture induced cracks. In addition, a substantial mutual influence of adjacent reinforcing elements has been identified. A reduction of the distance between the reinforcement thus results in a lower tolerable reduction of timber moisture content around the reinforcement.
Online Access
Free
Resource Link
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Environmental Response of a CLT Floor Panel: Lessons for Moisture Management and Monitoring of Mass Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue2161
Year of Publication
2018
Topic
Site Construction Management
Serviceability
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Floors

Moisture Monitoring and Modeling of Mass-Timber Building Systems

https://research.thinkwood.com/en/permalink/catalogue1833
Year of Publication
2018
Topic
Moisture
Material
CLT (Cross-Laminated Timber)
Author
Kordziel, Steven
Glass, Samuel
Pei, Shiling
Zelinka, Samuel
Tabares-Velasco, Paulo
Organization
Forest Products Laboratory
Year of Publication
2018
Country of Publication
Korea
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Moisture
Keywords
Moisture Monitoring
Hygrothermal Properties
High-Rise
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 20-23,2018. Seoul, Republic of Korea
Summary
The use of mass timber structural products in tall building applications (6–20 stories) is becoming more common around the world including North America. A potential concern is the environmental wetting of mass timber products during construction because such products may dry out more slowly than light-frame structural lumber, and wood, as an organic material, is susceptible to deterioration at elevated moisture contents. In order to better understand the moisture conditions present in high rise timber constructions, a long-term moisture monitoring program was implemented on an eight story, mixed-use, mass timber framed building in Portland, Oregon. The building was monitored with an array of moisture meters to track moisture content throughout the building’s construction and operation. This paper presents data covering a period just over one year starting from the manufacture of crosslaminated timber (CLT) panels. Hygrothermal properties of CLT samples of the same type used in the building were measured in the laboratory, and wetting and drying experiments on representative CLT samples were conducted. Simulated moisture contents using a one-dimensional hygrothermal model compared reasonably well with laboratory experiments and building site measurements.
Online Access
Free
Resource Link
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Building Climate – Long-Term Measurements to Determine the Effect on the Moisture Gradient in Timber Structures

https://research.thinkwood.com/en/permalink/catalogue266
Year of Publication
2014
Topic
Serviceability
Moisture
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Gamper, Andreas
Dietsch, Philipp
Merk, Michael
Organization
Technical University of Munich
Year of Publication
2014
Country of Publication
Germany
Format
Report
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Moisture Gradients
Climate
Load Carrying
Language
English
Research Status
Complete
Summary
Through long-term measurements of climate data (temperature, relative humidity) and timber moisture content on large-span timber structures in buildings of typical construction type and use, data sets were generated which deliver information on the sequence and magnitude of seasonal variations. The measurement of moisture in different depths of the cross-section is of particular interest to draw conclusions on the size and speed of adjustment of the moisture distribution to changing climatic conditions. The moisture gradient has direct influence on the size of the internal stresses and possible damage potential. Similarly, the results provide a review and extension of the previous classification of buildings into use classes. They allow for a more precise indication of range of resulting equilibrium moisture content for the specific use, enabling the installation of timber elements with adjusted moisture content. The results of the research project also support the development of appropriate monitoring systems, which could be used in the form of early warning systems based on climate measurements
Online Access
Free
Resource Link
Less detail

Moisture Monitoring Throughout the Construction and Occupancy of Mass Timber Builidings

https://research.thinkwood.com/en/permalink/catalogue1834
Year of Publication
2018
Topic
Moisture
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Author
Zelinka, Samuel
Glass, Samuel
Kordziel, Steven
Tabares-Velasco, Paulo
Pei, Shiling
Organization
Forest Products Laboratory
Publisher
University of Victoria
Year of Publication
2018
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Topic
Moisture
Keywords
Dimensional Instability
Microbial Attack
Fastener Corrosion
Cracking
Construction
Language
English
Conference
International Conference on New Horizons in Green Civil Engineering
Research Status
Complete
Notes
April 25-27,2018. Victoria, Canada
Summary
This paper presents preliminary findings from an ongoing research program instrumenting CLT buildings to measure wood moisture content. An overview of the research program is presented along with data from first year of moisture monitoring in an 8-story building in Portland, Oregon. This project measures the wood moisture content throughout the construction cycle, including the fabrication, shipping, staging, and erection of the panels. These preliminary field measurements can help characterize moisture changes in CLT during construction and guide the construction of future CLT buildings.
Online Access
Free
Resource Link
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Study of Moisture Conditions in a Multi-Story Mass Timber Building through the Use of Sensors and WUFI Hygrothermal Modeling

https://research.thinkwood.com/en/permalink/catalogue1429
Year of Publication
2018
Topic
Moisture
Site Construction Management
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Kordziel, Steven
Organization
Colorado School of Mines
Year of Publication
2018
Country of Publication
United States
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Moisture
Site Construction Management
Keywords
Production
Construction
Moisture Content
Drying Rate
Hygrothermal
In Situ
Language
English
Research Status
Complete
Summary
Mass timber products have shown promise as an innovative alternative to conventional framing systems for use in tall wood buildings, but this new trend in design and construction poses concerns for the long-term durability of the products. A major challenge that classically faces timber products is the threat of moisture-induced mold and decay fungi, which are a heightened concern in mass timber buildings exposed to the environment for extended duration during construction. Consequently, it is important to understand the hygric and thermal (hygrothermal) conditions that mass timber products can experience in multi-story constructions and to be able to quantify the behavior of the products for their suitable design and implementation. An eight-story mass timber building located in Portland, Oregon was chosen for this study and was instrumented for moisture content monitoring through its production, construction, and in-situ use. Record breaking precipitation levels occurred during the building’s construction and while dimension lumber and glulam products subsequently dried to acceptable levels, cross laminated timber products (CLT) dried more slowly. These measurements have an observed bias and the decay risk for the products is inconclusive. Samples of CLT used in the building were characterized for hygrothermal properties and integrated into WUFI, a simulation software, for analysis of the building. The software showed limitations for correctly simulating the behavior of CLT in isolated lab experiments and therefore a re-calibration was performed for accurate simulation. Preliminary on-site simulation results provide a decent approximation of observed data despite its high variance, but drying rate predicted by the program is lower than what was measured.
Online Access
Free
Resource Link
Less detail

10 records – page 1 of 1.