<p> </p><p>The compressive strength perpendicular to grain of cross laminated timber (CLT) was studied experimentally. The problem was also theoretically analyzed and a finite element model was created and solved using a commercial finite element software package. The experiments were carried out with three layer CLT specimens of dimensions 200x200x120 mm and 300x300x120 mm. In some of the experiments a contact free deformation measurement system was used to analyze the strain field during loading. Different ways to apply the load were used: over the whole surface of the specimens and by a 50 mm wide steel bar. The position of the steel bar in relation to the specimen edge and its orientation relative the surface grain direction was varied. It was found that the compression strength of the cross laminated timber depended on the way in which the load was applied. The compression strength perpendicular to grain was found vary from 2.9 N/mm² for specimens loaded by a line load at the edge of the specimen and parallel to the surface grain direction to 5.8 N/mm² for specimens loaded by a line load at the specimen centre and perpendicular to the surface fiber direction.</p><p><strong> </strong></p> / <p> </p><p>Tryckhållfastheten vinkelrät fiberriktningen i korslimmade massivträskivor (CLT) bestämdes experimentellt. Även teoretiska studier genomfördes med hjälp av ett kommersiellt finita elementprogram. Provningarna genomfördes på treskiktsskivor med måtten 200x200x120 mm samt 300x300x120 mm. I vissa av försöken användes dessutom ett mätsystem för beröringsfri deformationsmätning för att bestämma töjningsfälten. Olika sätt att belasta provbitarna undersöktes: genom att belasta hela provytan eller genom att belasta provet med en 50 mm bred stålstav. Stålstavens läge i förhållande till provbitens kant och dess orientering i förhållande till ytskiktets fiberriktning varierades. De experimentella resultaten visade att hållfastheten beror på hur provbitarna belastas. Tryckhållfastheten varierade mellan 2.9 N/mm² för fallet med en linjelast vid provbitens kant och orienterad parallellt med ytskiktets fiberriktning och 5.8 N/mm² för fallet med en linjelast mitt på provbiten och orienterad vinkelrät mot ytskiktets fiberriktning.</p><p><strong> </strong></p>

This thesis focuses on analyzing Cross Laminated Timber manufacture and use for the purpose of suggesting ways to enrich involved technology through the further application of digital fabrication techniques. Framed within the context of making and craft, product and processes are explored to search for opportunities where reevaluating current production methods may arise. It is also in this context that concepts of embodied/ embedded information and emergence are employed to suggest ideas for rethinking CLT, its fabrication and use. Based on research findings, new CLT panel types are prototyped and their required fabrication approaches proposed. The results are applied to a building design for a site in St. John’s, Newfoundland and Labrador.

Wood is a highly versatile renewable material (with carbon sequestering properties), that is light in weight, has good strength properties in both tension and compression while providing good rigidity and toughness, and good insulating properties (relative to typical structural materials). Engineered wood products combine the benefits of wood with engineering knowledge to create optimized structural elements. Cross-laminated timber (CLT), as one such engineered wood product, is an emerging engineering material which provides great opportunities for the building industry. While building with wood has many benefits, there are also some concerns, particularly decay. Should wood be exposed to elevated amounts of moisture, rots and moulds may damage the product or even risk the health of the occupants. As CLT panels are a relatively new engineered wood product, the moisture characteristics have yet to be properly assessed. Consequently, the amount of decay risk for CLT in building applications is unknown, and recommended protective actions during design construction and operation have yet to be determined. The goal of this research was to determine the moisture durability of CLT panels in wall assemblies and address concerns related to built-in construction moisture. The approach used to address the problem was to first determine select moisture properties of CLT panels through experimental approaches, and then use the results to calibrate a hygrothermal model to quantify the risks of wall assemblies. The wall assemblies were simulated in six different cities across Canada, representing a range of climates: Vancouver, B.C., Edmonton, A.B., Winnipeg, M.B., Ottawa, O.N., Québec City, Q.C., and St. John, New-Brunswick. The risks associated with moisture exposure during construction are also considered in the simulations. The experimental phase of the research was limited to moisture uptake tests. These tests were utilized to determine the liquid water absorption coefficient for four different types of full scale panels (2’x2’) and 12 clear wood samples. The panels were either made of 5-ply of Western-SPF, Eastern-SPF, Hemlock-Fir, or 3-ply of a generic softwood provided by a European CLT manufacturer; the clear samples were all cut from the same nominal 2x6 SPF-grade lumber. The panels were installed in a drying rack and gravimetrically tracked to assess the drying rates of the panels. Finite resources precluded more thorough material testing, but a parametric study was conducted to determine the relative impact of the missing material data on the final simulation results. In the hygrothermal simulations, four main wall assembly types were considered- those with either exterior or interior insulation, and those using either vapour permeable or impermeable air-water barriers. Various types of insulation and vapour control were also modelled. The simulations were run for a variety of interior relative humidities. The metric for comparison between the simulations was the water content of a 4mm thin layer on the extreme lamina of a CLT panel system. The results of the simulation suggest that vapour impermeable membranes, when install on dry CLT panels (less than 14% M.C.) do not pose moisture risks in any of the climates considered. However, when high levels of construction moisture is considered, only vapour permeable membranes controlled moisture risks by allowing the CLT panel to dry both to the interior and to the exterior.

Heavy timber construction is emerging as a viable alternative to conventional building materials, such as steel and concrete, for mid- and high rise structures. With the increasing presence of timber structures at or near potential targets comes an increased risk for damage to the structure and more importantly human casualties. The current provisions related to wood in the blast code (CSA, 2012) are limited and based on general understanding of the material behaviour rather than thorough research studies. Also, the standard does not clearly distinguish between the various types of engineered wood products. A study was undertaken to assess the behaviour of cross-laminated timber panels subjected to simulated blast loading using a shock tube apparatus. More specifically, the aim of this study was to investigate the behaviour of CLT panels subjected to static and dynamic loads to determine a dynamic increase factor in order to quantify high strain rate effects on this material. Testing was completed on a total of 18 CLT panels, with panel thicknesses of 105 and 175 mm corresponding to a 3-ply and 5-ply panel, respectively. An average dynamic increase factor of 1.28 on the resistance and no apparent increase in stiffness from static to dynamic loading were observed. Two resistance material predictive models that account for high strain-rate effects and the experimentally observed post-peak residual behavior were developed. A single degree-of-freedom model was validated using full-scale simulated blast load tests, and the predictions were found to match well with the experimental displacement-time histories.

I projektet dimensionerades ett tre våningar högt flerbostadshus i KL-trämoduler med utgångspunkt från dagens byggande av moduler som främst görs i träregelstommar. Vägg- och bjälklagsdimensioner beräknades och ritades upp. Metoder för infästningar och lyft av moduler med träregelstommar undersöktes genom intervjuer och applicerades i den mån som är möjlig för KL-trämoduler. Syftet var att ta fram en konstruktionsutformning för moduler av KL-trä avsedda för bostadsbyggande. Utformningen skall principiellt även kunna användas för andra liknande byggnader. Dimensioneringen visade att KL-träskivorna klarar av lasterna med god marginal. Avgörande för vägg- och bjälklagstjockleken var branddimensioneringen. Infästningar mellan olika byggnadsdelar kan göras på liknande sätt med KL-trä som med träregelstomme. Metoden att använda sig av stålförband i form av vinkelbeslag eller spikplåtar kan användas till de båda stomalternativen. Modullyft kan i viss mån utföras på samma sätt i de båda stommarna. / A three storey tall building was used as a reference object in this project and dimensioned with a starting point from timber frame modular constructions. Wall and floor dimensions are calculated and drawn. Methods for attachment and lifting of modules are examined through interviews and are, when possible, applied for the CLT modules. The purpose of this project was to design CLT modules intended for residential use. The goal of the design was that it can be used in similar buildings. The calculations showed that the fire requirements were the decisive factor when deciding the thickness of the walls and floors. Attachments between different building parts can be designed similarly in both timber frame modules and CLT modules. The method of using angle irons and nail plates is possible for both timber frame and CLT. The lifting of the modules can to some extent be executed similarly for the two frameworks.

De moduler som tillverkas i dagsläget baseras vanligtvis på traditionellträregelstomme. Det finns dock en möjlighet att istället tillverka moduler i KL-trä.Arbetets mål är att dimensionera infästningar för vertikal och horisontell lastverkanoch utforma infästningarna så att ett rationellt montage av KL-trämoduler möjliggörs.Infästningar som avses dimensioneras är från modul till grund samt från modul tillmodul. Litteraturstudie, platsbesök och intervju ligger till grund för val avinfästningsmetod. Förslaget resulterar i förband med stålplåt och dymlingar,skråskruvning samt förband med laskteknik. I framtida projekt med moduler i KL-träkan detta arbete ligga till grund för infästningsmetoder. / The modules currently manufactured are usually based on traditional wood frameconstruction. On the other hand, it is possible to manufacture modules in CLTinstead. The goal of the work is to design connections subjected to vertical andhorizontal load and design the connections so that a rational assembly of CLTmodulesis possible. Connections intended to be designed are from module tofoundation and from module to module. Literature survey, site visits and interviewsform the basis of the choice of attachment method. The proposal results in joints withsteel sheet and dowels, bevel screw, and single surface spline. In future projects withmodules in CLT, this work can be used as a basis for connection methods.

Cross Laminated Timber (CLT) has in recent years become a more important building material. This means that the demand for accurate calculation methods in building standards such as Eurocode 5 has increased. There is limited knowledge about the connections in CLT buildings which is an important part of a CLT structure. This thesis was therefore focused on investigating a wall-floor-wall type connection commonly found in platform type buildings.  An experimental and numerical study on typical wall-floor-wall connections was carried out in this thesis. In the experimental part 60 tests with 8 different configurations were conducted to investigate the influence of different parameters on the connection, moment capacity and rotational stiffness. During the tests the deformation of the specimens under four load levels were investigated. Compression tests were also performed on the specimens to determine the compressive strength and stiffness of the elements. In the numerical part two different models for the connection were created. One simplified model with rotational springs and one more complex model with compression springs. With these models the influence from the number of stories, span and thickness of the wall on the global behavior of a structure was investigated.  The result from this thesis shows that there is both moment capacity and rotational stiffness in the wall-floor-wall type connection that can be utilized in the design phase of a structure. This was proven by both the experimental and the numerical study. The parameters that influence the behavior of the connection most were the load level applied on the wall and the wall thickness. The model created in the numerical study showed great potential regarding the replication of the connection behavior observed in the experimental study.

The diploma thesis deals with an urban study and the design of a new residential structure in Kopřivnice. The city has not solved housing construction for the last 30 years, therefore it lacks housing development subject to current trends. The aim and motivation of the design was to create a new location that will be attractive not only for its residents but also for the surrounding area. A location that will offer housing, leisure activities and people.

This research was conducted to discover how the U.S. building construction and forest products sectors could benefit from the development of tall, cross-laminated (CLT) and mass timber buildings. Barriers that may restrict such development were also investigated. The primary benefits were discovered to be eco-performance and job creation. Code restrictions and material performance misconceptions were found to be the largest obstacles. Case studies of Treet, Tamedia, and the WIDC were conducted to demonstrate the benefits of tall wood buildings and the various paths around potential barriers. Opportunities for tall wood buildings in the U.S. are also discussed. This research discovered that a tall wood movement is gathering momentum in the U.S. To fully realize this potential, accurate information regarding the use of wood and the performance capacities of mass timber systems needs to be disseminated. Co-operation between academia and industry will also be necessary.

To provide fundamental information for the second generation of cross laminated timber manufacturing, wood sections that glued by different orientations were constructed and tested. To reveal adhesive differences, phenol resorcinol formaldehyde (PRF) and polyurethane (PU) adhesive were used and the gluelines were evaluated in accordance with different conditions for shear strength, wood failure, dimensional stability and delamination. A non-destructive testing method was applied to measure the dynamic modulus of elasticity (dMOE) change. The results showed that the radical wood section of lumber produced with the starsawn process had much less deformation and was more suitable for glueline. PRF had better performance than PU in terms of shear strength, dimensional stability, and delamination. Confocal microscopic pictures revealed that the tangential to tangential (TT) glueline showed the tendency of collapse, indicating a poor bond strength and therefore a poor glueline durability of TT glueline, especially when it was subject to wet conditions.