Skip header and navigation

64 records – page 1 of 7.

Adhesive-Bonded Timber-Concrete Composites - Experimental Investigation of Thermal-Hygric Effects

https://research.thinkwood.com/en/permalink/catalogue1519
Year of Publication
2016
Topic
Serviceability
Mechanical Properties
Material
Timber-Concrete Composite
Author
Seim, Werner
Eisenhut, Lars
Kühlborn, Sonja
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Timber-Concrete Composite
Topic
Serviceability
Mechanical Properties
Keywords
Climate
Long-term
Shear Strength
Deformation
Temperature
Moisture Content
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 597-605
Summary
The advantages of the two different building construction materials, timber and concrete, can be used effectively in adhesive-bonded timber-concrete composite constructions. The long-term behavior was investigated experimentally on small-scale shear and bond specimens under artificial, alternating climatic conditions and on fullscale specimens under natural climatic conditions for an application in construction practice. The development of the shear strength and the deformation behavior under permanent loads were studied, focusing on the different material behavior of wood and concrete regarding changes in temperature and moisture. The general applicability of adhesivebonded timber-concrete composites in construction practice was proved in the investigations.
Online Access
Free
Resource Link
Less detail

Applicability of Various Wood Species in Glued Laminated Timber - Parameter Study on Delamination Resistance and Shear Strength

https://research.thinkwood.com/en/permalink/catalogue592
Year of Publication
2014
Topic
Mechanical Properties
Connections
Material
Glulam (Glue-Laminated Timber)
Author
Jiang, Yuan
Schaffrath, Jörg
Knorz, Markus
Winter, Stefan
Van de Kuilen, Jan-Willem
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Connections
Keywords
Hardwood
Softwood
Gluability
Delamination
Shear Strength
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
In a current research project the gluability of various soft- und hardwood species and their applicability in glued laminated timber are investigated. The influence of the processing parameters on the delamination resistance and shear strength of the glue lines are presented in this work. The bonding forces, which are necessary for the integrity of a glue line, act in the interface within a distance that varies from nanometers to micrometers. The parameters that may have significant influence on the bonding strength and durability of adhesive joints are numerous and depend on the type of wood, adhesive and processing conditions.
Online Access
Free
Resource Link
Less detail

Bending Capacity of Orthogonal and Parallel Glulam T-section Beams

https://research.thinkwood.com/en/permalink/catalogue2476
Year of Publication
2020
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Bridges and Spans
Author
Wang, Jiejun
Yang, Tao
Ning, Fan
Rao, Zhenyu
Publisher
Eastern Macedonia and Thrace Institute of Technology (EMaTTech)
Year of Publication
2020
Country of Publication
Greece
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Bridges and Spans
Topic
Mechanical Properties
Keywords
Bearing Capacity
Stiffness
Integrity
Strain
Deflection
Ultimate Bearing Capacity
Shear Strength
Finite Element Model
Displacement
Failure Mechanism
Ductility
Language
English
Research Status
Complete
Series
Journal of Engineering Science and Technology Review
ISSN
1791-2377
Online Access
Free
Resource Link
Less detail

Bending Properties of Cross Laminated Timber with Layer Arrangement Using Different Species

https://research.thinkwood.com/en/permalink/catalogue1599
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Park, Sun-Hyang
Kim, Keon-Ho
Lee, Sang-Joon
Pang, Sung-Jun
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Delamination Test
Bending Test
Japanese Larch
Korean Red Pine
Shear Strength
MOE
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1931-1938
Summary
To evaluate the mechanical performance of the cross laminated timber (CLT) as the structural board materials using domestic species, the delamination test and the transverse bending test were conducted. The CLT used in the tests consisted of 3 layers of laminated timber made of Japanese larch and Korean red pine. The combinations for lamination were then divided on species of layer and grades of laminae. In the bending test, the loading directions were shown to be parallel and perpendicular to width direction of specimens, which is considered as the applicable direction in wooden building. The result of test showed that the bending strength of larix CLT was higher than that of pine CLT in combination of single species. In case of combination of mixed species, the bending properties CLT using larix major layer was higher than those of pine surface layer. It means that the surface layer has a more influence on bending properties of CLT, than the core layer does.
Online Access
Free
Resource Link
Less detail

Block Shear Strength and Delamination of Cross-Laminated Timber Fabricated with Japanese Larch

https://research.thinkwood.com/en/permalink/catalogue1220
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Gong, Yingchun
Wu, Guofang
Ren, Haiqing
Publisher
North Carolina State University
Year of Publication
2016
Country of Publication
United States
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Larch
Delamination
Block Shear Strength
Temperature
One-Component Polyurethane
Language
English
Research Status
Complete
Series
BioResources
Summary
Process parameters of cross-laminated timber (CLT) fabricated with Japanese larch were evaluated. The process parameters were designed by using an orthogonal test including pressure, glue consumption, and adhesive. Both delamination and block shear tests were conducted on CLT in accordance with GB/T 26899 (2011). The results showed that the optimum process parameters were A2B3C2 including pressure (1.2 MPa), glue consumption (200g/m2), and amount of sdhesive (one-component plyurethane). The weight loss and moisture absoption increased when the temperature increased, but the block shear strength decreased as the temperature was raised from 20C to 230C.
Online Access
Free
Resource Link
Less detail

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
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
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)
Topic
Mechanical Properties
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
Resource Link
Less detail

Bonding Strength Test Method Assessment for Cross-Laminated Timber Derived Stressed-Skin Panels (CLT SSP)

https://research.thinkwood.com/en/permalink/catalogue1404
Year of Publication
2017
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Luengo, Emilio
Hermoso, Eva
Cabrero, Juan Carlos
Arriaga, Francisco
Publisher
Springer Netherlands
Year of Publication
2017
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Stressed-Skin Panels
Shear Strength
Glue Lines
Shear Tests
Bending Tests
Bonding
Language
English
Research Status
Complete
Series
Materials and Structures
ISSN
1871-6873
Summary
Different methods, including bending tests and small and medium size shear tests, were used to assess the skin to stringer glue line shear strength of Radiata Pine Cross-Laminated Timber Derived Stressed-Skin Panels (CLT SSP). Bending test shear strengths were estimated using the mechanically jointed beam theory (gamma method) for CrossLaminated Timber (CLT) panels with modifications in the layers’ effective widths, and then compared with results from the small and medium size shear tests. Small and medium size shear tests proved to be possible methods for assessing bonding strength for factory production control. The small shear tests provided lower strength values and higher scatter results than those gathered from the medium size tests. The mean shear strength results obtained from bending tests were inferior to the values obtained from the small and medium size specimens. The bending tests proved necessary for assessing the mechanical behaviour of CLT SSP.
Online Access
Free
Resource Link
Less detail

Bondline Shear Strength and Wood Failure of European and Tropical Hardwood Glulams

https://research.thinkwood.com/en/permalink/catalogue1372
Year of Publication
2018
Topic
Connections
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Aicher, Simon
Ahmad, Zakiah
Hirsch, Maren
Publisher
Springer Berlin Heidelberg
Year of Publication
2018
Country of Publication
Germany
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Connections
Keywords
Keruing
Melangangai
Light Red Meranti
Sweet Chestnut
Oak
Beech
Ash
Teak
Hardwood
Shear Strength
Bondlines
Adhesives
Language
English
Research Status
Complete
Series
European Journal of Wood and Wood Products
ISSN
1436-736X
Summary
The study reports on block shear investigations with bondlines of face-glued laminations and matched solid wood specimens from hardwood glulam (GLT) beams produced industrially from eight technically and stand volume-wise important species. The European hardwoods comprised oak, beech, sweet chestnut and ash and the tropical species were teak, keruing, melangangai and light red meranti. The adhesives were phenol-resorcinol and melamine-urea. When combining all species in one sample, a rather strong linear relationship of bond and wood shear strength was observed. The ratio of bond vs. wood shear strength was for all species on the mean value level = 0.9, and likewise (with one exception) for the respective strengths’ 5%-quantiles. Consistent with literature, the test results showed no significant correlations between bond shear strength and density, wood shear strength and wood failure percentage of individual species, respectively. The investigations render the methodological basics of some international standards on bond quality verification as being inappropriate. New, empirically validated hardwood GLT bond requirements are proposed for discussion and implementation at the CEN and ISO levels. The strength ratio specifications reflect respective ANSI provisions, yet the reference quantity wood shear strength is now determined in an unbiased manner from matched GLT specimens. The wood failure verification proposal is based on the 10%-quantile and mean level for initial type testing and factory production control. The requirements further account for the pronounced difference observed in scatter of wood failure between European and tropical species.
Online Access
Free
Resource Link
Less detail

Deconstructable Timber-Concrete Composite Connectors

https://research.thinkwood.com/en/permalink/catalogue2740
Year of Publication
2020
Topic
Connections
Material
Timber-Concrete Composite
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Derikvand, Mohammad
Fink, Gerhard
Publisher
Society of Wood Science & Technology
Year of Publication
2020
Format
Conference Paper
Material
Timber-Concrete Composite
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Connections
Keywords
Deconstructable Connections
Deconstructable Connector
TCC
Push-Out Tests
Shear Strength
Slip Modulus
Failure Mode
Self-Tapping Screws
Language
English
Conference
Society of Wood Science and Technology International Convention
Research Status
Complete
Summary
The application of deconstructable connectors in timber-concrete composite (TCC) floors enables the possibility of disassembly and reuse of timber materials at the end of building’s life. This paper introduces the initial concept of a deconstructable TCC connector comprised of a self-tapping screw embedded in a plug made of rigid polyvinyl chloride and a level adjuster made of silicone rubber. This connection system is versatile and can be applied for prefabrication and in-situ concrete casting of TCC floors in both wet-dry and dry-dry systems. The paper presents the results of preliminary tests on the shear performance of four different configurations of the connector system in T-section glulam-concrete composites. The shear performance is compared to that of a permanent connector made with the same type of self-tapping screw. The failure modes observed are also analyzed to provide technical information for further optimization of the connector in the future.
Online Access
Free
Resource Link
Less detail

Development of Novel Standardized Structural Timber Elements Using Wood-Wood Connections

https://research.thinkwood.com/en/permalink/catalogue2747
Year of Publication
2020
Topic
Design and Systems
Connections
Material
CLT (Cross-Laminated Timber)
Author
Gamerro, Julien
Publisher
Lausanne, EPFL
Year of Publication
2020
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Topic
Design and Systems
Connections
Keywords
Timber Construction
Connections
Digital Fabrication
Design for Manufacturing and Assembly
Structural Design
Structural Frameworks
Semi-Rigid Connection
Experimental
Shear Strength
Compression Strength
Wood-Wood Connections
Bending Test
Bending Stiffness
Numerical Model
Load Carrying Capacity
Slip Modulus
Language
English
Research Status
Complete
Summary
Traditional wood-wood connections, widely used in the past, have been progressively replaced by steel fasteners and bonding processes in modern timber constructions. However, the emergence of digital fabrication and innovative engineered timber products have offered new design possibilities for wood-wood connections. The design-to-production workflow has evolved considerably over the last few decades, such that a large number of connections with various geometries can now be easily produced. These connections have become a cost-competitive alternative for the edgewise connection of thin timber panels. Several challenges remain in order to broaden the use of this specific joining technique into common timber construction practice: (1) prove the applicability at the building scale, (2) propose a standardized construction system, (3) develop a convenient calculation model for practice, and (4) investigate the mechanical behavior of wood-wood connections. The first building implementation of digitally produced through-tenon connections for a folded-plate structure is presented in this work. Specific computational tools for the design and manufacture of more than 300 different plates were efficiently applied in a multi-stakeholder project environment. Cross-laminated timber panels were investigated for the first time, and the potential of such connections was demonstrated for different engineered timber products. Moreover, this work demonstrated the feasibility of this construction system at the building scale. For a more resilient and locally distributed construction process, a standardized system using through-tenon connections and commonly available small panels was developed to reconstitute basic housing components. Based on a case-study with industry partners, the fabrication and assembly processes were validated with prototypes made of oriented strand board. Their structural performance was investigated by means of a numerical model and a comparison with glued and nailed assemblies. The results showed that through-tenon connections are a viable alternative to commonly used mechanical fasteners. So far, the structural analysis of such construction systems has been mainly achieved with complex finite element models, not in line with the simplicity of basic housing elements. A convenient calculation model for practice, which can capture the semi-rigid behavior of the connections and predict the effective bending stiffness, was thus introduced and subjected to large-scale bending tests. The proposed model was in good agreement with the experimental results, highlighting the importance of the connection behavior. The in-plane behavior of through-tenon connections for several timber panel materials was characterized through an experimental campaign to determine the load-carrying capacity and slip modulus required for calculation models. Based on the test results, existing guidelines were evaluated to safely apply these connections in structural elements while a finite element model was developed to approximate their performance. This work constitutes a firm basis for the optimization of design guidelines and the creation of an extensive database on digitally produced wood-wood connections. Finally, this thesis provides a convenient design framework for the newly developed standardized timber construction system and a solid foundation for research into digitally produced wood-wood connections.
Online Access
Free
Resource Link
Less detail

64 records – page 1 of 7.