Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Bending Properties of Cross Laminated Timber (CLT) with a 45° Alternating Layer Configuration
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.ORCID-id: 0000-0001-7091-6696
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.ORCID-id: 0000-0001-5872-2792
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.ORCID-id: 0000-0001-8404-7356
SP Technical Research Institute of Sweden, SP Sustainable Built Environment, Skellefteå, Sweden, SP Trätek, SP Technical Research Institute of Sweden, Skellefteå.
2016 (Engelska)Ingår i: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 11, nr 2, s. 4633-4644Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Bending tests were conducted with cross laminated timber (CLT) panels made using an alternating layer arrangement. Boards of Norway spruce were used to manufacture five-layer panels on an industrial CLT production line. In total, 20 samples were tested, consisting of two CLT configurations with 10 samples of each type: transverse layers at 45° and the conventional 90° arrangement. Sample dimensions were 95 mm × 590 mm × 2000 mm. The CLT panels were tested by four point bending in the main load-carrying direction in a flatwise panel layup. The results indicated that bending strength increased by 35% for elements assembled with 45° layers in comparison with 90° layers. Improved mechanical load bearing panel properties could lead to a larger span length with less material.

Ort, förlag, år, upplaga, sidor
2016. Vol. 11, nr 2, s. 4633-4644
Nationell ämneskategori
Annan maskinteknik
Forskningsämne
Träteknik
Identifikatorer
URN: urn:nbn:se:ltu:diva-11156DOI: 10.15376/biores.11.2.4633-4644Scopus ID: 2-s2.0-84965159370Lokalt ID: a1093b71-f2f8-4b06-9af1-b46a7c406aa8OAI: oai:DiVA.org:ltu-11156DiVA, id: diva2:984105
Anmärkning

Validerad; 2016; Nivå 2; 20160331 (aliwan)

Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Ingår i avhandling
1. Mechanics of Cross-Laminated Timber
Öppna denna publikation i ny flik eller fönster >>Mechanics of Cross-Laminated Timber
2018 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Increasing awareness of sustainable building materials has led to interest in enhancing the structural performance of engineered wood products. Wood is a sustainable, renewable material, and the increasing use of wood in construction contributes to its sustainability. Multi-layer wooden panels are one type of engineered wood product used in construction.

There are various techniques to assemble multi-layer wooden panels into prefabricated, load-bearing construction elements. Assembly techniques considered in the earliest stages of this research work were laminating, nailing, stapling, screwing, stress laminating, doweling, dovetailing, and wood welding. Cross-laminated timber (CLT) was found to offer some advantages over these other techniques. It is cost-effective, not patented, offers freedom of choice regarding the visibility of surfaces, provides the possibility of using different timber quality in the same panel at different points of its thickness, and is the most well-established assembly technique currently used in the industrial market.

Building upon that foundational work, the operational capabilities of CLT were further evaluated by creating panels with different layer orientations. The mechanical properties of CLT panels constructed with layers angled in an alternative configuration produced on a modified industrial CLT production line were evaluated. Timber lamellae were adhesively bonded in a single-step press procedure to form CLT panels. Transverse layers were laid at a 45° angle instead of the conventional 90° angle with respect to the longitudinal layers’ 0° angle.

Tests were carried out on 40 five-layered CLT panels, each with either a ±45° or a 90° configuration. Half of these panels were evaluated under bending: out-of-plane loading was applied in the principal orientation of the panels via four-point bending. The other twenty were evaluated under compression: an in-plane uniaxial compressive loading was applied in the principal orientation of the panels. Quasi-static loading conditions were used for both in- and out-of-plane testing to determine the extent to which the load-bearing capacity of such panels could be enhanced under the current load case. Modified CLT showed higher stiffness, strength, and fifth-percentile characteristics, values that indicate the load-bearing capacity of these panels as a construction material. Failure modes under in- and out-of-plane loading for each panel type were also assessed.

Data from out-of-plane loading were further analysed. A non-contact full-field measurement and analysis technique based on digital image correlation (DIC) was utilised for analysis at global and local scales. DIC evaluation of 100 CLT layers showed that a considerable part of the stiffness of conventional CLT is reduced by the shear resistance of its transverse layers. The presence of heterogeneous features, such as knots, has the desirable effect of reducing the propagation of shear fraction along the layers. These results call into question the current grading criteria in the CLT standard. It is suggested that the lower timber grading limit be adjusted for increased value-yield.

The overall experimental results suggest the use of CLT panels with a ±45°-layered configuration for construction. They also motivate the use of alternatively angled layered panels for more construction design freedom, especially in areas that demand shear resistance. In addition, the design possibility that such 45°-configured CLT can carry a given load while using less material than conventional CLT suggests the potential to use such panels in a wider range of structural applications. The results of test production revealed that 45°-configured CLT can be industrially produced without using more material than is required for construction of conventional 90°-configured panels. Based on these results, CLT should be further explored as a suitable product for use in more wooden-panel construction.

Ort, förlag, år, upplaga, sidor
Luleå: Luleå University of Technology, 2018
Serie
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Nyckelord
CLT assembly, CLT manufacture, Crosslam, DIC analysis, Digital speckle photography, Full-field mechanics, Laminated wood product, Mass timber engineering, Non-contact measurement, Non-destructive, Optical measurement, Panel configuration, Strain localization, X-lam, Alternativ byggmetod, Bildkorrelation, Hållbart byggande, KL- trä, Korslimmat trä, Skjuvtöjning, Massivträ, Träkonstruktion
Nationell ämneskategori
Maskinteknik Annan maskinteknik
Forskningsämne
Träteknik
Identifikatorer
urn:nbn:se:ltu:diva-68729 (URN)978-91-7790-150-1 (ISBN)978-91-7790-151-8 (ISBN)
Presentation
2018-06-20, Hörsal A, Luleå tekniska universitet, Skellefteå, 10:00 (Engelska)
Opponent
Handledare
Anmärkning

External cooperation: Martinson Group AB and Research Institutes of Sweden (RISE)

Tillgänglig från: 2018-05-15 Skapad: 2018-05-15 Senast uppdaterad: 2018-06-13Bibliografiskt granskad

Open Access i DiVA

fulltext(995 kB)452 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 995 kBChecksumma SHA-512
2cc1f0fc2787892e71954bf28d30dbf1efd6b6627caa1b6bd8c51dff0f4b9e34aeb058d68c657616954293e0525562107a7d88cbc52302ddb63fe3fc46f9bf71
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltextScopus

Personposter BETA

Buck, DietrichWang, AliceHagman, Olle

Sök vidare i DiVA

Av författaren/redaktören
Buck, DietrichWang, AliceHagman, Olle
Av organisationen
Träteknik
I samma tidskrift
BioResources
Annan maskinteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 452 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 1509 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf