Korslimmat trä – Optimering av tvärsnittsuppbyggnad
(2019) In TVSM-4000 VBVL01 20191Structural Mechanics
Department of Construction Sciences
- Abstract
- Cross-laminated timber, CLT, is a rather new building material. It consists of an odd number of layers consisting of lumber boards stacked together, where each layer is rotated 90 degrees in comparison to the adjacent layers. The material is used both as a load-carrying element as well as a non-load-carrying element, such as stairs.
Today there is only one established producer of CLT in Sweden. Due to the increasing popularity of the material, there are now several other producers that have started or are starting with CLT production. For new CLT producers it is imperative to optimize their products regarding technical and economical aspects. This thesis enlightens how such an optimization can be done and acknowledging which technical... (More) - Cross-laminated timber, CLT, is a rather new building material. It consists of an odd number of layers consisting of lumber boards stacked together, where each layer is rotated 90 degrees in comparison to the adjacent layers. The material is used both as a load-carrying element as well as a non-load-carrying element, such as stairs.
Today there is only one established producer of CLT in Sweden. Due to the increasing popularity of the material, there are now several other producers that have started or are starting with CLT production. For new CLT producers it is imperative to optimize their products regarding technical and economical aspects. This thesis enlightens how such an optimization can be done and acknowledging which technical aspects that are the most important while optimizing the product selection for a CLT manufacturer.
As a background to the thesis, to get a common knowledge of how CLT works, and to include the producer’s view of the manufacturing process and product selection, an initial literature study was conducted, followed by interviews with the manufacturers. The optimization was mainly done using a spreadsheet where different cross sections (number of layers, layer thickness and quality) were analyzed with respect to different load scenarios. The thesis has several limitations including fire performance and exclusion of asymmetrical cross-sections.
The results show that elements consisting of 5 or 7 layers are better suited as a floor system thanks to the fact that they can manage longer spans. Regarding walls, elements consisting of 3 layers are suitable in most cases, as their capacities rapidly increase when the layer thicknesses are increased. Furthermore, the results show that several factors other than the cross-sectional structure need to be considered for the optimization to be complete. Costs are a complex factor to include in an optimization as it is difficult to derive a cost for an element without including factors that are specific for each manufacturer (Less) - Abstract (Swedish)
- Korslimmat trä, KL-trä, är ett förhållandevis nytt byggnadsmaterial i byggbranschen. Det består av ett udda antal skikt av lameller av konstruktionsvirke, där varje skikt av lameller ligger roterade 90 grader i förhållande till intilliggande skikt. Materialet används både i den bärande stommen och som stomkomplettering i form av exempelvis trappor.
Idag finns endast en etablerad tillverkare på den svenska marknaden för KL-trä. I och med materialets växande popularitet är nu flera andra svenska tillverkare igång med eller i uppstartsfas av KL-trätillverkning. För nya KL-träproducenter är det naturligtvis avgörande att man ur ett tekniskt och ekonomiskt perspektiv optimerar sina produkter. Detta examensarbete handlar om att undersöka hur... (More) - Korslimmat trä, KL-trä, är ett förhållandevis nytt byggnadsmaterial i byggbranschen. Det består av ett udda antal skikt av lameller av konstruktionsvirke, där varje skikt av lameller ligger roterade 90 grader i förhållande till intilliggande skikt. Materialet används både i den bärande stommen och som stomkomplettering i form av exempelvis trappor.
Idag finns endast en etablerad tillverkare på den svenska marknaden för KL-trä. I och med materialets växande popularitet är nu flera andra svenska tillverkare igång med eller i uppstartsfas av KL-trätillverkning. För nya KL-träproducenter är det naturligtvis avgörande att man ur ett tekniskt och ekonomiskt perspektiv optimerar sina produkter. Detta examensarbete handlar om att undersöka hur en sådan optimering kan göras och att belysa vilka tekniska egenskaper hos materialet som är viktigast att ta hänsyn till i samband med utformning av produktutbud för KL-trätillverkare.
Som bakgrund till optimeringen och för att få en grundförståelse för hur materialet KL-trä fungerar samt för att få ta del av producenternas perspektiv på tillverkningsprocessen och produktval, utfördes initialt i arbetet en litteraturstudie följt av en intervjustudie. Optimeringen utfördes sedan huvudsakligen med hjälp av ett kalkylprogram där olika tvärsnittsuppbyggnader (antal skikt, skikttjocklek samt materialkvalitet) analyserades utifrån olika belastningssituationer. Optimeringen har flera avgränsningar, däribland brandkrav och exkludering av osymmetriska KL-träskivor.
Resultatet pekar på att 5- och 7-skiktsskivor av KL-trä lämpar sig bäst för bjälklag tack vare att de klarar längre spännvidder. För väggelement av KL-trä räcker 3-skiktsskivor långt då de snabbt kommer upp i höga kapaciteter då skikttjocklekarna ökar. Vidare kan man utifrån resultatet se att det är flera andra faktorer utöver själva tvärsnittsuppbyggnaden som behöver tas hänsyn till vid en optimering för att den ska bli fullständig. Exempelvis är kostnad en komplex faktor som är svår att ta med i en optimering då man inte kan ta fram en direkt kostnad för ett element utan att blanda in tillverkarspecifika faktorer. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8990640
- author
- Ingvarsson, Lukas LU and Kvist, Rebecka LU
- supervisor
-
- Erik Serrano LU
- organization
- course
- VBVL01 20191
- year
- 2019
- type
- M2 - Bachelor Degree
- subject
- keywords
- CLT, cross-sectional structure, timber construction
- publication/series
- TVSM-4000
- report number
- TVSM-4005
- ISSN
- 0281-6679
- language
- Swedish
- id
- 8990640
- alternative location
- http://www.byggmek.lth.se/english/publications/tvsm-4000-thid-5000/
- date added to LUP
- 2020-02-14 08:55:58
- date last changed
- 2020-02-14 08:55:58
@misc{8990640,
abstract = {{Cross-laminated timber, CLT, is a rather new building material. It consists of an odd number of layers consisting of lumber boards stacked together, where each layer is rotated 90 degrees in comparison to the adjacent layers. The material is used both as a load-carrying element as well as a non-load-carrying element, such as stairs.
Today there is only one established producer of CLT in Sweden. Due to the increasing popularity of the material, there are now several other producers that have started or are starting with CLT production. For new CLT producers it is imperative to optimize their products regarding technical and economical aspects. This thesis enlightens how such an optimization can be done and acknowledging which technical aspects that are the most important while optimizing the product selection for a CLT manufacturer.
As a background to the thesis, to get a common knowledge of how CLT works, and to include the producer’s view of the manufacturing process and product selection, an initial literature study was conducted, followed by interviews with the manufacturers. The optimization was mainly done using a spreadsheet where different cross sections (number of layers, layer thickness and quality) were analyzed with respect to different load scenarios. The thesis has several limitations including fire performance and exclusion of asymmetrical cross-sections.
The results show that elements consisting of 5 or 7 layers are better suited as a floor system thanks to the fact that they can manage longer spans. Regarding walls, elements consisting of 3 layers are suitable in most cases, as their capacities rapidly increase when the layer thicknesses are increased. Furthermore, the results show that several factors other than the cross-sectional structure need to be considered for the optimization to be complete. Costs are a complex factor to include in an optimization as it is difficult to derive a cost for an element without including factors that are specific for each manufacturer}},
author = {{Ingvarsson, Lukas and Kvist, Rebecka}},
issn = {{0281-6679}},
language = {{swe}},
note = {{Student Paper}},
series = {{TVSM-4000}},
title = {{Korslimmat trä – Optimering av tvärsnittsuppbyggnad}},
year = {{2019}},
}