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10 records – page 1 of 1.

Bonding Performance of Adhesive Systems for Cross-Laminated Timber Treated with Micronized Copper Azole Type C (MCA-C)

https://research.thinkwood.com/en/permalink/catalogue2200
Year of Publication
2020
Topic
Design and Systems
Connections
Material
CLT (Cross-Laminated Timber)
Application
General Application
Author
Lim, Hyungsuk
Tripathi, Sachin
Tang, Juliet
Publisher
ScienceDirect
Year of Publication
2020
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
General Application
Topic
Design and Systems
Connections
Keywords
Preservatives
Micronized Copper Azole-Type C
Bonding Performance
Delamination Tests
Block Shear Tests
Adhesives
Block Shear Strength
Wood Failure Percentage
Language
English
Research Status
Complete
Series
Construction and Building Materials
Summary
The feasibility of manufacturing cross-laminated timber (CLT) from southern yellow pine (United States grown) treated with micronized copper azole type C (MCA-C) preservative was evaluated. Lumber (2x6 visually graded no. 2 boards) was treated to two retention levels (1.0 and 2.4 kg/m3 ), planed to a thickness of 35 mm, and assembled along with an untreated control group using three adhesive systems following product specifications: melamine formaldehyde (MF), resorcinol formaldehyde (RF), and one-component polyurethane (PUR). Block shear and delamination tests were conducted to examine the bonding performance in accordance with ASTM D905 and ASTM D2559 Standards, respectively. One-way analysis of variance and Kruskal-Wallis H test were conducted to evaluate the effects of preservative retention and adhesive type on block shear strength (BSS) and wood failure percentage (WFP). Regardless of adhesive type, the 1.0 kg/m3 retention treatment significantly lowered BSS compared to the untreated control. CLT composed of the laminations treated at 2.4 kg/m3 maintained BSS when PUR and RF were used but not MF. The average WFP of each CLT configuration ranged from 89% to 99%. The untreated CLT specimens did not experience any delamination under accelerated weathering cycles. The delamination rates of the treated specimens assembled using MF and RF increased with the preservative retention level, while PUR provided delamination rates less than 1% to the laminations treated at both levels. These combined data suggest that, under the conditions tested, PUR provided overall better bonding performance than MF and RF for MCA-C treated wood.
Online Access
Free
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Methods for Practice-Oriented Linear Analysis in Seismic Design of Cross Laminated Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue2304
Year of Publication
2020
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
General Application

Predicting Failure of Notched Cross-Laminated Timber Plates Including the Effect of Environmental Stresses

https://research.thinkwood.com/en/permalink/catalogue2354
Year of Publication
2020
Topic
Mechanical Properties
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
General Application
Author
Nairn, John
Year of Publication
2020
Country of Publication
United States
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
General Application
Topic
Mechanical Properties
Design and Systems
Keywords
Delamination
Fracture Mechanisms
Residual Stresses
Language
English
Research Status
Complete
Series
Wood Material Science & Engineering
Online Access
Free
Resource Link
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Smart Manufacturing of Curved Mass Timber Components by Self-shaping

https://research.thinkwood.com/en/permalink/catalogue2379
Year of Publication
2020
Topic
Design and Systems
Material
Timber (unspecified)
Application
Wood Building Systems
Author
Grönquist, Philippe
Publisher
ETH Zurich
Year of Publication
2020
Country of Publication
Switzerland
Format
Thesis
Material
Timber (unspecified)
Application
Wood Building Systems
Topic
Design and Systems
Keywords
Manufacturing
Mass Timber
Up-scaling
Form-stable Curved Elements
Self-Shaping
Language
English
Research Status
Complete
Notes
DOI link: https://doi.org/10.3929/ethz-b-000405617
Summary
With the rise of complex and free-form timber architecture enabled by digital design and fabrication, timber manufacturing companies increasingly need to produce curved components. In this thesis, a novel approach for the manufacturing of curved timber building components is proposed and analyzed. Following biological role models such as the bending of pine cone scales, a smart way to curve wood at large-scale is given by the biomimetic concept of bi-layered laminated wood. This principle enables large programmed material deformations upon controlled moisture content change. The main objectives of this thesis are the in-depth understanding of the mechanics of self-shaping wood bilayers and the up-scaling of the already known principle from the laboratory to the industrial scale in order to enable an application as form-stable curved elements in architecture. Hereby, the main challenges addressed are the accurate prediction of shape-change in terms of the natural variability in wood material parameters, the scale-dependent impact of moisture gradients on mechanical behavior, and the influence of wood-specific time- and moisture-dependent deformation mechanisms such as creep or mechano-sorption in the shaping process. Major impacts of these aspects on the shaping behavior could be demonstrated by the use of continuum-mechanical material models adapted to wood, both in the form of analytical and numerical models. Based on the gained insight, the up-scaling process to industrial manufacturing was successfully made possible. A collaborative project realized in 2019, the 14 m high Urbach tower, is presented as a proof of concept for application and competitiveness of the novel biomimetic method for production of curved mass timber components. Furthermore, next to self-shaping by bending to single-curved components, possibilities and limitations for achieving double-curved structures using wood bilayers in a gridshell configuration are analyzed and discussed.
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Free
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Zero-Waste Mass-Timber Residential High-Rise: A Sustainable High-density Housing Solution

https://research.thinkwood.com/en/permalink/catalogue2381
Year of Publication
2020
Topic
Environmental Impact
Design and Systems
Material
Timber (unspecified)
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
van Houten, Robert
Publisher
Delft University of Technology
Year of Publication
2020
Country of Publication
Netherlands
Format
Thesis
Material
Timber (unspecified)
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Environmental Impact
Design and Systems
Keywords
Mass Timber
Residential
High-Rise
End of Life
Language
English
Research Status
Complete
Summary
More and more people live in cities. The building industry is responsible for 33% of waste production and is set to increase further to 50% in 2025. The energy efficiency is continuously increased, but the waste production at the end of life of a building is largely ignored. This design proposes a solution in the form of a zero-waste high-rise design. It uses only recyclable or renewable materials. Mass-timber is chosen as the main material as it is not only renewable and easily reusable, it is also a storage of CO2. The design reuses the foundation of existing buildings, and with the lightweight properties of mass-timber, increases the density on the location by building taller. The design is four times taller as the current buildings. To allow for sustainable densification, the design offers public and collective qualities. The building has been designed is such a way to be easily refitted during its life cycle or to be completely disassembled at the end of life.
Online Access
Free
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Review of State of the Art of Dowel Laminated Timber Members and Densified Wood Materials as Sustainable Engineered Wood Products for Construction and Building Applications

https://research.thinkwood.com/en/permalink/catalogue2385
Year of Publication
2020
Topic
Design and Systems
Mechanical Properties
Material
DLT (Dowel Laminated Timber)
Application
Wood Building Systems
General Application

Seismic Design of Timber Buildings: Highlighted Challenges and Future Trends

https://research.thinkwood.com/en/permalink/catalogue2388
Year of Publication
2020
Topic
Design and Systems
Seismic
Material
Timber (unspecified)
Application
Wood Building Systems
Author
Stepinac, Mislav
Šušteršic, Iztok
Gavric, Igor
Rajcic, Vlatka
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
Timber (unspecified)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Seismic Design
Tall Timber Buildings
Timber Composites
Seismic Retrofitting
Eurocode 8
Language
English
Research Status
Complete
Series
Applied Sciences
Summary
Use of timber as a construction material has entered a period of renaissance since the development of high-performance engineered wood products, enabling larger and taller buildings to be built. In addition, due to substantial contribution of the building sector to global energy use, greenhouse gas emissions and waste production, sustainable solutions are needed, for which timber has shown a great potential as a sustainable, resilient and renewable building alternative, not only for single family homes but also for mid-rise and high-rise buildings. Both recent technological developments in timber engineering and exponentially increased use of engineered wood products and wood composites reflect in deficiency of current timber codes and standards. This paper presents an overview of some of the current challenges and emerging trends in the field of seismic design of timber buildings. Currently existing building codes and the development of new generation of European building codes are presented. Ongoing studies on a variety topics within seismic timber engineering are presented, including tall timber and hybrid buildings, composites with timber and seismic retrofitting with timber. Crucial challenges, key research needs and opportunities are addressed and critically discussed.
Online Access
Free
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Design Concept for a Greened Timber Truss Bridge in City Area

https://research.thinkwood.com/en/permalink/catalogue2392
Year of Publication
2020
Topic
Design and Systems
Environmental Impact
Material
Timber (unspecified)
Application
Bridges and Spans
Author
Kromoser, Benjamin
Ritt, Martin
Spitzer, Alexandra
Stangl, Rosemarie
Idam, Friedrich
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
Timber (unspecified)
Application
Bridges and Spans
Topic
Design and Systems
Environmental Impact
Keywords
Wooden Trusses
Timber Bridges
Timber Engineering
Greened Structures
Vertical Green
Sustainable Structural Engineering
Digital Design
Parametric Design
Automated Construction
Resource-Efficient Structural Engineering
Language
English
Research Status
Complete
Series
Sustainability
Summary
Properly designed wooden truss bridges are environmentally compatible construction systems. The sharp decline in the erection of such structures in the past decades can be led back to the great effort needed for design and production. Digital parametric design and automated prefabrication approaches allow for a substantial improvement of the efficiency of design and manufacturing processes. Thus, if combined with a constructive wood protection following traditional building techniques, highly efficient sustainable structures are the result. The present paper describes the conceptual design for a wooden truss bridge drawn up for the overpass of a two-lane street crossing the university campus of one of Vienna’s main universities. The concept includes the greening of the structure as a shading design element. After an introduction, two Austrian traditional wooden bridges representing a good and a bad example for constructive wood protection are presented, and a state of the art of the production of timber trusses and greening building structures is given as well. The third part consists of the explanation of the boundary conditions for the project. Subsequently, in the fourth part, the conceptual design, including the design concept, the digital parametric design, the optimization, and the automated prefabrication concept, as well as the potential greening concept are discussed, followed by a summary and outlook on future research.
Online Access
Free
Resource Link
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Environmental and Economic Evaluation of Small-Scale Bridge Repair Using Cross-Laminated Timber Floor Slabs

https://research.thinkwood.com/en/permalink/catalogue2397
Year of Publication
2020
Topic
Design and Systems
Environmental Impact
Material
CLT (Cross-Laminated Timber)
Application
Bridges and Spans

Equivalent-frame Model for Elastic Behaviour of Cross-laminated Timber Walls with Openings

https://research.thinkwood.com/en/permalink/catalogue2417
Year of Publication
2020
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Mestar, Mohammed
Doudak, Ghasan
Caola, Maurizio
Casagrande, Daniele
Publisher
ICE Publishing
Year of Publication
2020
Country of Publication
Scotland
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Design and Systems
Keywords
Computational Mechanics
Structural Frameworks
Timber Structures
Elastic Behaviour
Language
English
Research Status
Complete
Series
Proceedings of the Institution of Civil Engineers - Structures and Buildings
Online Access
Free
Resource Link
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10 records – page 1 of 1.