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Comparison between Predicted and Measured Moisture Content and Climate in 12 Monitored Timber Structures in Switzerland

https://research.thinkwood.com/en/permalink/catalogue2895
Year of Publication
2021
Topic
Moisture
Application
Wood Building Systems
Author
Schiere, Marcus
Franke, Bettina
Franke, Steffen
Müller, Andreas
Organization
Bern University of Applied Sciences
Editor
Brandner, Reinhard
Publisher
MDPI
Year of Publication
2021
Format
Journal Article
Application
Wood Building Systems
Topic
Moisture
Keywords
Moisture Content
Climate
Meteorological Data
Building Standards
Monitoring
Research Status
Complete
Series
Buildings
Summary
Wood is a hygroscopic material that primarily adapts its moisture content to the surrounding relative humidity. The climate in a structure or building depends on the building type and the region the structure is located in. In this study, the effect of region on the moisture content of wood was investigated. Measurements taken in 12 ventilated timber structures were compared to the theoretical equilibrium moisture content calculated from the relative humidity and temperature in 107 meteorological stations across Switzerland. The monitored load-bearing elements were made of softwood and protected from the direct impact of weather. The climatic conditions around the Alps, a mountain range that runs from France to Austria and crosses Switzerland, can be divided into the following three different regions: (1) south of the Alps, where the climate is affected mainly by the Mediterranean sea; (2) north of the Alps, where the climate is affected by the Atlantic Ocean; and (3) the inner Alps, where the climate is considered to be relatively dry. The climatic conditions of the three separate regions were reflected in the measurements made in the monitored timber structures. Differences between the regions were quantified. The moisture content and relative humidity, similarly to temperature, depended on altitude (above sea level).
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Design of Connections in Timber Structures

https://research.thinkwood.com/en/permalink/catalogue1937
Year of Publication
2018
Topic
Connections
Design and Systems
Material
CLT (Cross-Laminated Timber)
Author
Bader, Thomas
Blaß, Hans Joachim
Bocquet, Jean-François
Branco, Jorge
Brandner, Reinhard
Manuel Cabrero, José
de Proft, Kurt
Descamps, Thierry
Dietsch, Philipp
Franke, Bettina
Franke, Steffen
Görlacher, Rainer
Jockwer, Robert
Jorissen, André
Kleiber, Marion
Lemaître, Romain
Munch-Andersen, Jørgen
Pazlar, Tomaž
Ranasinghe, Keerthi
Ringhofer, Andreas
Sandhaas, Carmen
Schweigler, Michael
Stepinac, Mislav
Tuhkanen, Eero
Verbist, Maxime
Yurrita, Miguel
Editor
Sandhaas, Carmen
Munch-Andersen, Jørgen
Dietsch, Philipp
Publisher
COST (European Cooperation in Science and Technology)
Year of Publication
2018
Format
Book/Guide
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Design and Systems
Keywords
Eurocode 5
Fasteners
Screws
Dowel Type Fastener
Glued-In Rods
Numerical Modeling
Europe
Load Distribution
Research Status
Complete
Summary
This state-of-the-art report has been prepared within COST Action FP1402 Basis of structural timber design from research to standards, Working Group 3 Connections. The Action was established to create an expert network that is able to develop and establish the specific information needed for standardization committee decisions. Its main objective is to overcome the gap between broadly available scientific results and the specific information needed by standardization committees. This necessitates an expert network that links practice with research, i.e. technological developments with scientific background. COST presents the ideal basis to foster this type of joint effort. Chapter 8 Connections presents an integral part of Eurocode 5 and is in need of revision. This state-of-the-art report shall provide code writers with background information necessary for the development of the so-called Second Generation of the Eurocodes, now aimed to be produced in 2022.
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Failure Modes and Reinforcement Techniques for Timber Beams – State of the Art

https://research.thinkwood.com/en/permalink/catalogue11
Year of Publication
2015
Topic
Serviceability
Material
Solid-sawn Heavy Timber
Application
Beams
Author
Harte, Annette
Franke, Bettina
Franke, Steffen
Publisher
ScienceDirect
Year of Publication
2015
Format
Journal Article
Material
Solid-sawn Heavy Timber
Application
Beams
Topic
Serviceability
Keywords
Damage
Deterioration
Failure
Fasteners
Large Span
Loading
Reinforcement
Retrofit
Research Status
Complete
Series
Construction and Building Materials
Summary
Highly loaded and large span timber beams are often used for halls, public buildings or bridges. Reinforcement of beams may be required to extend the life of the structure, due to deterioration or damage to the material/product or change of use. The paper summarises methods to repair or enhance the structural performance of timber beams. The main materials/products cross sections and geometries used for timber beam are presented. Furthermore, their general failure modes are described and typical retrofitting and reinforcement techniques are given. The techniques include wood to wood replacements, use of mechanical fasteners and additional strengthening materials/products.
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Investigation on Elements Presenting Cracks in Timber Structures

https://research.thinkwood.com/en/permalink/catalogue477
Year of Publication
2014
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Franke, Steffen
Magnière, Noëlie
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Keywords
Cracks
Numerical Model
Stiffness
Load Carrying Capacity
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Cracks in timber members influence the stiffness and load-carrying behaviour but only rudimentary rules are given to evaluate cracked members. Therefore, an investigation to gather information about the most frequent characteristics of cracked timber structures has been carried out. This investigation provides the main characteristics of both the timber elements and the crack distributions encountered. These main characteristics have then been used to define a numerical model in order to investigate the impact of cracks on the stiffness and load-carrying capacity of timber beams. Based on these results, the existing rules considering cracks in timber beams can be evaluated and new rules can be developed.
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Load Carrying Capacity of Cracked Beams

https://research.thinkwood.com/en/permalink/catalogue1544
Year of Publication
2016
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Franke, Steffen
Franke, Bettina
Magnière, Noëlie
Year of Publication
2016
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Keywords
Cracks
Stiffness
Modulus of Elasticity
Load Carrying Capacity
Numerical Investigations
Experimental Investigations
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1123-1130
Summary
The increasing number of wood structure amongst large and potentially public buildings gave a new impulse to the assessment of timber structures. For assessing the state of timber elements, cracks are a key indicator. Therefore, experimental and numerical investigations on not cracked and partly cracked timber members were carried out and analysed. The results show no influence on the stiffness and modulus of elasticity for partly cracked beams. The experimental results were used for the development of analytical and validation the numerical solutions for the assessment of the residual load carrying capacity of cracked timber members. Several models predicting the residual load carrying capacity depending on the crack situation are presented.
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Long Term Monitoring of Timber Bridges - Assessment and Results

https://research.thinkwood.com/en/permalink/catalogue2124
Year of Publication
2013
Topic
Moisture
Serviceability
Application
Bridges and Spans
Author
Franke, Bettina
Franke, Steffen
Müller, Andreas
Vogel, Mareike
Scharmacher, Florian
Tannert, Thomas
Publisher
Scientific Net
Year of Publication
2013
Format
Journal Article
Application
Bridges and Spans
Topic
Moisture
Serviceability
Keywords
Monitoring
Bridge
Moisture Content
Climate
Research Status
Complete
Series
Advanced Materials Research
Summary
Timber bridges have been built for decades all around the world. The hygroscopic material behavior of wood leads to the change of the moisture content of the wood and the dimensions depending on the climate. Therefore in regular inspections following questions arise: what happens with the wood due to the climate changes? Are there major changes of the moisture content? Are there differences between the natural material axes or within the cross section of the structural members? To answer these questions, traffic timber bridges with big cross sections are long-term monitored within a research project. The results of the moisture contents measured and a comparison between the different measuring groups and positions are presented. The analyses confirm that the moisture content in the wood follows the climate changes delayed and with smaller amplitude against the calculated equilibrium moisture content. In first steps, a different behavior of the change of the moisture content could be determined over the cross-section and along the span of the member.
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Mechanical Properties of Beech CLT

https://research.thinkwood.com/en/permalink/catalogue1526
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Franke, Steffen
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Beech
Strength
Stiffness
Delamination Tests
Rolling Shear Failure
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 660-666
Summary
The use of relatively new constructions products like Cross laminated timber (CLT) is increasing significantly. It is planned to extend the production of CLT by producing them out of beech or of beech and spruce in combination as hybrid product. The objective is to provide high performing materials which compensate weak points in soft wood products. In order to use and implement the product, the mechanical behaviour of a CLT plate of beech were investigated. The potential of beech is shown in terms of known strength values. Experimental tests for the evaluation of the strength and stiffness values for beech CLT for different situations as well as delamination tests were performed. Failure cases of the mechanical tests are presented and discussed where the rolling shear failure was in major focus for the discussion.
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Timber Structures 3.0 - New Technology for Multi-Axial, Slim, High Performance Timber Structures

https://research.thinkwood.com/en/permalink/catalogue1557
Year of Publication
2016
Topic
Mechanical Properties
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Zöllig, Stefan
Frangi, Andrea
Franke, Steffen
Muster, Marcel
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Mechanical Properties
Design and Systems
Keywords
Butt-Joint
Biaxial Load Bearing
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1290-1297
Summary
Until today, all known timber building systems allow only slabs with a uniaxial load bearing action. Thereby, in comparison to normal reinforced concrete slabs, timber slabs are often thick, expensive and complicated to build. The reason for this is that there is no efficient connection technology to rigidly connect timber slab elements to each other. Alternative solutions are hybrid structural systems with concrete or steel, however, this combination of materials results in some disadvantages especially in terms of weight, ecology, construction time and costs. In the framework of a large research project a new timber slab system has been developed and already tested in first real applications. The developed slab system is designed for housing, commercial and industrial buildings. The slab system works as a flat slab carrying vertical loads biaxial and consists of timber slab elements like CLT glued together on site with a high performance butt-joint bonding technology. Research about the central slab element, the butt-joint bonding and fire tests have already been performed. The research showed the feasibility of this innovation. In 2015 a first prototype was built in Thun, Switzerland. A large three year research project started 2016 with the goal to reach market maturity.
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TS3 – A New Technology for Efficient Timber Structures

https://research.thinkwood.com/en/permalink/catalogue2924
Year of Publication
2020
Topic
Market and Adoption
Material
CLT (Cross-Laminated Timber)
Application
Beams
Floors
Roofs
Author
Franke, Steffen
Zöllig, Stefan
Organization
Bern University of Applied Sciences
Publisher
Irispublishers
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Beams
Floors
Roofs
Topic
Market and Adoption
Keywords
Timber Flat Slab
Biaxial Load Bearing
Butt-joint Bonding
TS3
Research Status
Complete
Series
Current Trends in Civil & Structural Engineering
Summary
Until today, all known timber building systems allow only slabs with a uniaxial load bearing action. In the framework of a large research project a new timber slab system has been developed and already tested in first real applications. The developed slab system is designed for housing, commercial and industrial buildings. The slab system works as a flat slab carrying vertical loads biaxial and consists of timber slab elements like CLT glued together on site with a high performing butt-joint bonding technology. This technology was called Timber structures 3.0 (TS3). Several research and tests about the performance of the different slab elements and the butt-joint bonding have been performed. First structures have been built and proof the system.
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9 records – page 1 of 1.