Skip header and navigation

5 records – page 1 of 1.

Bond Behavior between Glulam and GFRP’s by Pullout Tests

https://research.thinkwood.com/en/permalink/catalogue560
Year of Publication
2011
Topic
Connections
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Author
Sena-Cruz, José
Branco, Jorge
Jorge, Marco
Barros, Joaquim
Silva, Catarina
Cunha, Vitor
Publisher
ScienceDirect
Year of Publication
2011
Country of Publication
Netherlands
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Design and Systems
Keywords
GFRP
Bond behavior
Pull-Out Tests
Stress-Slip
Language
English
Research Status
Complete
Series
Composites Part B: Engineering
Summary
To evaluate the bond behavior between glulam and GFRP rods, applied according to the nearsurface mounted strengthening technique, an experimental program composed of beam and direct pullout tests was carried. In this experimental program three main variables were analyzed: the GFRP type, the GFRP location into the groove, and the bond length. From the monitoring system it was registered the loaded and free end slips, and the pullout force. Based on these experimental results, and applying an analytical-numerical strategy, the local bond stress-slip relationship was calculated. In this work the tests are described, the obtained results are presented and discussed, and the applicability of the inverse analysis to obtain the local bond law is demonstrated.
Online Access
Free
Resource Link
Less detail

Influence of Moisture Content and Gaps on the Withdrawal Resistance of Self Tapping Screws in CLT

https://research.thinkwood.com/en/permalink/catalogue299
Year of Publication
2014
Topic
Connections
Mechanical Properties
Moisture
Material
CLT (Cross-Laminated Timber)
Author
Silva, Catarina
Ringhofer, Andreas
Branco, Jorge
Lourenço, Paulo
Schickhofer, Gerhard
Organization
National Congress of Experimental Mechanics
Year of Publication
2014
Country of Publication
Portugal
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Moisture
Keywords
Self-Tapping Screws
Withdrawal
Gaps
Moisture Content
Language
English
Conference
9th National Congress of Experimental Mechanics
Research Status
Complete
Notes
October 15-17, 2014, Aveiro, Portugal
Summary
Self-tapping screws (STS) have been proclaimed as the easiest solution for structural timber connections, in special for cross laminated timber (CLT) constructions. In order to understand deeply the composite model “CLT-STS”, an experimental campaign which comprised 270 withdrawal tests was carried out. Maximum withdrawal load capacity of self-tapping screws inserted in plane side of a three layered CLT panel was evaluated considering three main parameters: moisture levels of CLT (i), number of gaps (ii) and the width of gaps (iii). Regarding (i), connections were tested with CLT at 8%, 12% and 18% of moisture content. Concerning (ii) and (iii), different test configurations with 1, 2 and 3 gaps, with 0 or 4mm, were tested. The influences of moisture content and number of gaps were modeled. Further a correlation between test results and a prediction model developed by Uibel and Blaß (2007) has been proposed.
Online Access
Free
Resource Link
Less detail

The Influences of Moisture Content Variation, Number and Width of Gaps on the Withdrawal Resistance of Self Tapping Screws inserted in Cross Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue1359
Year of Publication
2016
Topic
Connections
Moisture
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Silva, Catarina
Branco, Jorge
Ringhofer, Andreas
Lourenço, Paulo
Schickhofer, Gerhard
Publisher
ScienceDirect
Year of Publication
2016
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Moisture
Mechanical Properties
Keywords
Withdrawal Tests
Withdrawal Resistance
Self-Tapping Screws
Moisture Content
Gaps
Language
English
Research Status
Complete
Series
Construction and Building Materials
Summary
A large experimental campaign comprised of 470 withdrawal tests was carried out, aiming to quantify the withdrawal resistance of self-tapping screws (STS) inserted in the side face of cross laminated timber (CLT) elements. In order to deeply understand the “CLT-STS” composite model, the experimental tests considered two main parameters: (i) simple and cyclic changes on moisture content (MC) and (ii) number and width of gaps. Regarding (i), three individual groups of test specimens were stabilized with 8%, 12% and 18% of moisture content and one group was submitted to a six month RH cycle (between 30% and 90% RH). Concerning (ii), different test configurations with 0 (REF), 1, 2 and 3 gaps, and widths equal to 0mm (GAP0) or 4mm (GAP4), were tested. The influences of MC and number of gaps were modeled by means of least square method. Moreover, a revision of a prediction model developed by Uibel and Blaß (2007) was proposed. The main findings of the experimental campaign were: the decrease of withdrawal resistance for specimens tested with MC=18% in most configurations; the unexpected increase of withdrawal resistance as the number of gaps with 0mm increased; and, the surprising increase of withdrawal resistance for REF specimens submitted to the RH cycle.
Online Access
Free
Resource Link
Less detail

A Project Contribution to the Development of Sustainable Multi-Storey Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1162
Year of Publication
2013
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Silva, Catarina
Branco, Jorge
Lourenço, Paulo
Year of Publication
2013
Country of Publication
Portugal
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Keywords
Urban Timber System
Language
English
Conference
Portugal SB13
Research Status
Complete
Notes
October 30-November 1 2013, Guimarães, Portugal
Summary
Wood is a natural material, renewable, easily recyclable, and able to store carbon-dioxide, which makes tall timber buildings a solution with potential to answer the main sustainability targets. Cross laminated timber (CLT) has been pointed out as the best wood-based material to make this ambition a real thing. In order to understand why, this paper introduces the material and describe some demonstration buildings recently built. Based on diagnosed weaknesses of CLT buildings, it is presented an initial propose for a new CLT/glulam hybrid construction system, called Urban Timber (UT) system, which aims be able to support taller timber buildings. The main motivation was the development of a wood-based structural solution that provides more spatial flexibility and wider versatility for visual architectural expressions. The system is described and illustrated, considering concerns related with structural behavior, architectural value, structural connections and wood shrinkage.
Online Access
Free
Resource Link
Less detail

UT System : A Structural System to Build Taller Urban Timber Houses with Aspired Spatial Flexibility

https://research.thinkwood.com/en/permalink/catalogue277
Year of Publication
2014
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Silva, Catarina
Branco, Jorge
Lourenço, Paulo
Organization
International Association for Housing Science
Year of Publication
2014
Country of Publication
Portugal
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Keywords
Urban Densification
Tall Timber
Urban Timber (UT) System
Moisture
Durability
Fire Resistance
Acoustic Performance
Joints
Language
English
Conference
40th IAHS World Congress on Housing
Research Status
Complete
Notes
December 16-19, 2014, Funchal, Portugal
Summary
In past few years, in consequence to the continuous increase of urban densities and seeking for a more sustainable profile for construction, some new proposals for tall timber city housing have emerged. The development of new wood-based materials, like cross laminated timber (CLT), has made possible to believe to build high with timber. Demonstration buildings located in different locations around the world contribute to the development of this new concept of urban housing. With the exception of few recent proposals based on hybrid systems, majority of buildings so far built are fully based in the monolithic construction system offered by CLT panels. Despite all the advantages related with this monolithic system, two main important weaknesses related with architectural freedom have been pointed out: the excessive compartmentalization of inner spaces and the external expression of an extruded box with reduced openings. Inspired on new CLT/steel and CLT/concrete hybrid proposals and their advantages in comparison to the CLT monolithic system, a CLT/glulam hybrid construction system, named UT system (urban timber system), has been developed. CLT remains the main structural material in the UT system but, glulam linear elements are used to reduce the CLT walls both inside and in the building perimeter. Further, based in the bundled tube concept, UT system looks into the possibility of overcome eccentricity problems caused by non-symmetrical location of vertical cores and consequently, offers more design freedom. UT system is described and illustrated, considering concerns related with structural system, tall building specificities, construction sequences, architectural design possibilities, moisture effects, durability, fire resistance, acoustic performance and joints between timber elements.
Online Access
Free
Resource Link
Less detail