Dissertations / Theses on the topic 'Cross-laminated timber panels'

Developed in the mid-1990s in Austria and Germany, Cross Laminated Timber (CLT) is an innovative wood product known for its strength in both orthogonal directions, and its dimensional stability, making it a sustainable alternative to concrete slabs. CLT is created through the cross-lamination process, which glues together odd number of layers of wood planks placed in orthogonally alternating directions. With the growing interest in the application of CLT in North America, numerous studies has been conducted to characterize the acoustical properties of CLT panels. However, most of them focused on the sound-transmission aspect of CLT, very few on the sound absorption. This thesis will explore the sound-absorption characteristics of CLT, the effect on overall room-acoustical conditions, the utilization of resonant sound-absorbing layers on CLT to make it more sound-absorptive, and proposed solutions to improve this performance aspect. To demonstrate the low sound absorption and poor acoustical conditions in rooms with exposed and untreated CLT panels, several in-situ reverberation-time (RT) measurements were conducted in multiple buildings in British Columbia. Average sound-absorption coefficients and estimated Speech Intelligibility Indices (SII) were calculated as baseline performance measures for this study. Based on the results from five different buildings, involving 8 rooms configurations, average sound-absorption coefficients for exposed CLT panels are approximately between 0.02 to 0.13, resulting in barely acceptable conditions for verbal communication. To optimize the sound-absorption characteristics of prototype CLT panels, a transfer-matrix model has been developed to predict the performance of multi-layered CLT panels. This theoretical model was then validated by using three different sound-absorption measurement methods (impedance tube, spherical decoupling, and reverberation chamber) for multiple HR array configurations. After identifying the important parameters of an HR system and their effects on performance, a final prototype configuration with Helmholtz Resonator Array was then created with the goal of improving the room- acoustical performance of CLT, as well as responding to input from the CLT manufacturers and experts. Both the theoretical and experimental results confirmed that the proposed solution has the required sound-absorption performance and achieves all research objectives.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate

The use of Cross-Laminated Timber products has increased in recent years with a range of structural applications including CLT tall buildings and folded structures. As CLT is used in more innovative structural applications the need for specific methods of design and analysis are apparent. A review of the literature demonstrates that despite the increasing popularity of CLT in construction there are limited methods for the design and analysis of CLT panels and structures that fully utilise its unique properties. Manufacturer data relating to the CLT material properties varies how the cross directional laminas are considered. Finally it was found that there is limited published knowledge regarding CLT material properties for panels loaded non-tangentially to the direction of the timber grain. A method for predicting failure loads and modes has been presented and compared with experimental test data. A Strut and Tie model is proposed for the analysis of CLT panels, a methodology originally developed to design of reinforced concrete deep beams. The Strut and Tie approach considers panel geometry, loads, supports, different properties in tension and compression and was adapted to consider anisotropic behaviour. The procedure, advantages and limitations have been presented and a model developed for an application in CLT. The use of this model is considered for the analysis of simple CLT panel loadings. The behaviour of CLT at different timber grain angles demonstrate a complex composite behaviour influencing the strut and tie capacities. The definition of node sizes was also found to be critical to the definitions of the struts and ties and hence the capacity of the sections. Comparison of experimental tests to the model demonstrates some application to using a Strut and Tie in CLT panels. It identifies where additional investigation is required to improve, develop and validate the model into a method that may be used for full-scale CLT panels and structures in design practice and consider a variety of geometries and loading arrangements.

Guadua angustifolia Kunth (Guadua) is a bamboo species native to South and Central America that has been widely used for structural applications in small and large-scale buildings, bridges and temporary structures. Currently, its structural use is regulated within seismic resistant building codes in countries such as Peru and Colombia. Nevertheless, Guadua remains a material for vernacular construction associated with high levels of manual labour and structural unpredictability. Guadua buildings are limited to two storeys due to the overall flexibility of the slender and hollow culms and its connection systems. Its axial specific stiffness is comparable to that of steel and hardwoods, but unlike wood, Guadua’s hollow structure and lack of ray cells render it prone to buckling along the grain and to transverse crushing. As a result, Guadua’s mainstream use in construction and transformation into standard sizes or engineered Guadua products is scarce. Therefore, this work focussed on the development of standardised flat industrial structural products from Guadua devising replicable manufacturing technologies and engineering methods to measure and predict their mechanical behaviour. Cross-laminated Guadua panels were developed using thermohydro-mechanically modified and laminated flat Guadua strips glued with a high performance resin. Guadua was subjected to thermo-hydro-mechanical (THM) treatments that modified its microstructure and mechanical properties. THM treatment was applied to Guadua with the aim of tackling the difficulties in the fabrication of standardised construction materials and to gain a uniform fibre content profile that facilitated prediction of mechanical properties for structural design. Densified homogenous flat Guadua strips (FGS) were obtained. Elastic properties of FGS were determined in tension, compression and shear using small-clear specimens. These properties were used to predict the structural behaviour of G-XLam panels comprised of three and five layers (G-XLam3 and G-XLam5) by numerical methods. The panels were assumed as multi-layered systems composed of contiguous lamellas with orthotropic axes orientated at 0º and 90º. A finite element (FE) model was developed, and successfully simulated the response of G-XLam3 & 5 panels virtually loaded with the same boundary conditions as the following experimental tests on full-scale panels. G-XLam3 and G-XLam5 were manufactured and their mechanical properties evaluated by testing large specimens in compression, shear and bending. Results from numerical, FE predictions and mechanical testing demonstrated comparable results. Finally, design and manufacturing aspects of the G-XLam panels were discussed and examples of their architectural and structural use in construction applications such as mid-rise buildings, grid shells and vaults are presented. Overall, this research studies THM treatments applied to Guadua in order to produce standardised engineered Guadua products (EGP), and provides guidelines for manufacturing, testing, and for the structural analysis and design with G-XLam panels. These factors are of key importance for the use of Guadua as a mainstream material in construction.

The Vertically Oriented Interlocking Timber (VOIT) panel is a new solid wood panel similar to Interlocking Cross Laminated Timber (ICLT) and the more commonly known Cross Laminated Timber (CLT). Like ICLT, VOIT panels use timber connections instead of the adhesives or metal fasteners common to CLT. The difference of VOIT is the orientation of the layers. Where CLT and ICLT panels alternate the orientation of each layer, VOIT panels orient all the layers in the same direction. The vertically oriented layers are then attached to one another by smaller horizontal dovetail members.Two types of VOIT panels were provided to be tested for in-plane lateral loading. Type I had three rows of horizontal dovetail members connecting the layers and Type II had four rows of dovetail members as well as two diagonal members to provide stiffness. Two panels of each type were provided, measuring 8 ft. wide, 8 ft. tall, and 13.75 in. thick. Each panel was disassembled after monotonic lateral in-plane loading to determine possible failure modes. Testing results suggest the VOIT panels to be comparable in shear strength to other wood shear walls, including light frame, CLT, and ICLT walls. A two-part analytical model was created to determine the deflection of the wall when loaded as well as the shear strength of the wall. The model predicted deflection and wall strength reasonably well. Due to the small sample size, additional testing is necessary to confirm the results of the Type I and Type II VOIT panels. Additional testing with more variations of the panel and member geometries is also needed to validate the scope of the model.

Les panneaux en bois lamellé croisé (en anglais CLT - Cross Laminated Timber) sont des éléments de structure composés de couches en bois collées entre eleese et empilées de façon croisée. Chaque couche est composée de planches en bois juxtaposées et généralement non collées sur leur chants. Dans cette thèse, nous étudions l'influence sur le comportement mécanique des espacements entre planches des panneaux avec une approche par modélisation et expérimentation. Les panneaux CLT standard sont considérés comme des panneaux avec des espacements de très faible dimension par opposition aux panneaux avec espacements importants que nous appelons panneaux innovants. Nous modélisons dans un premier temps le comportement en flexion de panneaux standard à l'aide d'un modèle de couche homogène équivalente basée sur des hypothèses simplifiées de la mécanique d'une couche avec chants collés ou non collés. Nous observons un bon accord entre les résultats de notre modélisation et des résultats expérimentaux issus de la littérature. Des études paramétriques sont ensuite réalisés portant sur certaines propriétés des panneaux.Nous avons ensuite réalisé des essais de flexion 4-points sur des panneaux CLT standard et innovants pour quantifier l'influence des espacements sur la réponse mécanique des panneaux. Il se trouve que l'influence des effets de cisaillement transverse sur le comportement élastique et à la rupture augmente avec l'augmentation des vides dans le panneau.Afin de prendre correctement en compte les effets du cisaillement, les CLT espacés sont modélisés comme des plaques épaisses périodiques à l'aide d'un modèle de plaque d'ordre supérieur. Ce modèle a été appliqué à la géométrie des panneaux CLT espacés avec un schéma d'homogénéisation périodique. Des méthodes simplifiées existantes ont également été comparées avec les résultats des essais et le modèle de plaque. De plus, des résultats d'essais de cisaillement dans le plan des panneaux CLT standard issus de la littérature ont été comparés avec nos résultats. La raideur de flexion des CLT espacés peut être prédite avec des méthodes simples existantes, alors que seule la modélisation que nous proposons permet de prédire le comportement en cisaillement transverse et dans le plan. Finalement, des formules analytiques ont été obtenues pour prédire le comportement élastique des CLT espacés. Ces formules donnent une bonne approximation u comportement des CLT espacés et peuvent être utilisées dans le cadre d'une démarche pratique de dimensionnement.Enfin, une étude concernant l'analyse du comportement au feu des panneaux CLT standard est présentée. La comparaison entre des résultats d'essais au feu et une modélisations avancée et simplifiée a permis de proposer une possible amélioration de la méthode de dimensionnement au feu standard
Cross Laminated Timber (CLT, or crosslam) panels are engineered timber products composed of layers made of wooden lamellas placed side by side, glued on their upperand lower faces and stacked crosswise. In the present thesis, the influence of lateral spaces between lamellas of each layer on the panel’s mechanical response is investigated with modeling and tests. Both configurations of standard panels having short spaces and innovative CLT panels with large spaces are analyzed.As a first approach, the bending behavior of standard crosslam was modeled by means of an equivalent-layer model based on simplified hypotheses on mechanical properties of laterally glued or unglued layers. The good agreement of the predicted behavior with an experiment of the literature finally allowed an investigation on several CLT properties by means of parameter studies.Then, 4-points bending tests on standard and innovative CLT floors were performed in order to quantify the influence of periodic spaces on the panels' mechanical response. It appears that the influence of transverse shear effects on the elastic and failure behavior of spaced CLT increases with the increasing spaces between boards.In order to take into account transverse shear effects, spaced CLT have been modeled as periodic thick plates by means of a higher-order plate theory for laminated plates. This model has been applied to the geometry of spaced CLT with a periodic homogenization scheme. Existing simplified methods for spaced crosslam were compared as well with refined modeling and test results. Moreover, available in-plane shear tests of the literature have been compared to the modeling results. It appears that the bending behavior of spaced CLT can be predicted with simplified existing approaches, while only the more refined modeling can predict the in-plane and transverse shear behavior. Then, closed-form solutions for predicting spaced CLT elastic behavior were derived in order to encourage the application of spaced CLT panels in modern timber construction.One further study within this thesis concerns the analysis of fire-exposed standard CLT floors. The comparison between test results and both advanced and simplified modeling led to a suggestion for a possible improvement the standard fire design model

Wind loads acting on wooden building structures need to be dealt with adequately in order to ensure that neither the serviceability limit state nor the ultimate limit state is exceeded. For the structural designer of tall buildings, avoiding the possibly serious consequences of heavy wind loading while taking account at the same time of the effects of gravitation can be a real challenge. Wind loads are usually no major problem for low buildings, such as one- to two-storey timber structures involving ordinary walls made by nailing or screwing sheets of various types to the frame, but when taller structures are designed and built, serious problems may arise.

Since wind speed and thus wind pressure increases with height above the ground and the shear forces transmitted by the walls increase accordingly, storey by storey, considerable efforts can be needed to handle the strong horizontal shear forces that are exerted on the bottom floor in particular. The strong uplift forces that can develop on the wind side of a structure are yet another matter that can be critical. Accordingly, a structure needs to be anchored to the substrate or to the ground by connections that are properly designed. Since the calculated uplift forces depend very much upon the models employed, the choice of models and simplifications in the analysis that are undertaken also need to be considered carefully.

The present licentiate thesis addresses questions of how wind loads acting on multi-storey timber buildings can be best dealt with and calculated for in the structural design of such buildings. The conventional use of sheathing either nailed or screwed to a timber framework is considered, together with other methods of stabilizing timber structures. Alternative ways of using solid timber elements for stabilization are also of special interest.

The finite element method was employed in simulating the structural behaviour of stabilizing units. A study was carried out of walls in which sheathing was nailed onto a timber frame. Different structural levels were involved, extending from modelling the performance of a single fastener and of the connection of the sheathing to frame, to the use of models of this sort for studying the overall structural behaviour of wall elements that possess a stabilizing function. The results of models used for simulating different load cases for walls agreed reasonably well with experimental test results. The structural properties of the fasteners binding the sheathing to the frame, as well as of the connections between the members of the frame were shown to have a strong effect on the simulated behaviour of shear wall units.

Regarding solid wall panels, it was concluded that walls with a high level of both stiffness and strength can be produced by use of such panels, and also that the connections between the solid wall panels can be designed in such a way that the shear forces involved are effectively transmitted from one panel to the next.

The use of timber in building structures is steadily increasing. cross laminated timber (CLT) is an engineered wood product made of an uneven number of layers of lamellas glued at an angle of 90 degrees to each other. This gives CLT high stiffness and strength to bending in all directions, and capability of taking load both in-plane and out-of-plane. Due to the large size of CLT elements, they allow for quick assembly of strong structures. Due to both economic and environmental reasons it is important for producers of CLT to optimize the use of the wood material by using the timber with higher stiffness and strength where it is most needed. This thesis is about evaluating the bending and shear stiffness of CLT elements, when used as plates, depending on the quality of wood used in the different layers. Four-point bending tests are carried out on elements of different compositions and a parametrized finite element model is created. Thus, the model is validated on the basis of experimental tests to evaluate the influence of different quality of different layers. The measured dynamic MoE proved to have good potential to be used as the longitudinal bending stiffness in an FE-model, with a deviation from the experimental tests of less than 1%. There is a strong correlation between the bending stiffness and bending strength of the plates. The effective rolling shear modulus in pine was calculated to be around 170 MPa for pine of dimension 40 x 195 mm2 . Grading the boards into two different classes used for different layers proved to increase the MoE of the plates by 11-17% for 3- and 5-layer CLT.

This doctoral thesis addresses questions of how wind loads acting on multistoreytimber buildings can be dealt with by structural design of such buildings.The conventional use of sheathing either nailed or screwed to a timberframework is considered, together with other stabilizing structures such ascross-laminated timber panels.The finite element method was employed in simulating the structuralbehaviour of stabilizing wall units. A series of studies was carried out of walls inwhich the sheathing was nailed to a timber frame. Different structural levelswere studied starting with modelling the performance of single sheathing-toframingconnections, to the use of models for studying the overall structuralbehaviour of walls. The results of calculations using models for simulation ofwalls subjected to different loading agree reasonably well with experimentalresults. The structural properties of the connections between the sheathing andthe frame, as well as of the connections between the members of the frame,were shown to have a substantial effect on the simulated behaviour of shearwall units. Both these types of connections were studied and described inappended papers.Regarding cross-laminated timber wall panels, it was concluded that walls witha high level of both stiffness and strength can be produced by the use of suchpanels, and also that the connections between the solid wall panels can bedesigned in such a way that the shear forces involved are transmitted from onepanel to the next in an efficient manner.Other topics in the thesis include the properties of connections between shearwalls and the rest of the building. Typically high tension forces occur at specificpoints in a timber structure. These forces need to be transmitted downwards inthe structure, ultimately connecting them to the substrate. A lap-joint that maybe used for this purpose has been studied using generalized Volkersen theory.Finally the maximum capacity of a conventional rail to substrate connection hasbeen examined using linear and nonlinear fracture mechanics.

2011/2012
Cross-laminated timber, also known as X-Lam or CLT, is well established in Europe as a construction material. Recently, implementation of X-Lam products and systems has begun in countries such as Canada, United States, Australia and New Zealand. So far, no relevant design codes for X-Lam construction were published in Europe, therefore an extensive research on the field of cross-laminated timber is being performed by research groups in Europe and overseas. Experimental test results are required for development of design methods and for verification of design models accuracy. This thesis focuses on the continuation of SOFIE research project which started in 2005, conducted by IVALSA Trees and Timber Research Institute (San Michele all' Adige, Trentino, Italy). The aim of this project is the development of multi-storey timber building systems using prefabricated cross-laminated panels. As several parts of Italy are earthquake-prone areas, seismic resistance of such building system has to be ensured. Thus, within the scope of the SOFIE project, an extensive experimental research on seismic resistance of X-Lam building system has been performed. The project started with performance of racking tests on wall panels with different layouts of connections and openings and pseudo-dynamic tests on a full scale one-storey building, continued with shaking table tests on a 3-storey building and on a 7-storey building, the latter one conducted at E-Defense facility in Miki, Japan. Experimental tests provided excellent outcomes, as the buildings were able to survive a series of strong recorded earthquakes, such as Kobe earthquake (1995), virtually undamaged, while at the same time demonstrating significant energy dissipation. In the scope of this thesis, an extended experimental programme on typical X-Lam connections was performed at IVALSA Research Institute. In addition, cyclic tests were carried out on full-scale single and coupled cross-lam wall panels with different configurations and mechanical connectors subjected to lateral force. The outcomes of these tests were used for evaluation of mechanical properties, ductility ratio, energy dissipation, and impairment of strength, which are all needed in seismic design and are currently not provided by codes of practice such as the Eurocode 8. In addition, analytical models to predict stiffness and strength at different building levels such as connections, wall systems and entire buildings were developed. Further, capacity design method for X-Lam buildings was introduced and was verified with extensive database of experimental results. In the capacity design, overstrength factors are needed, thus these factors were evaluated based on experimental tests on X-Lam subassemblies. Experimental results served also for calibration of advanced component FE models for non-linear static and dynamic numerical analyses of X-Lam walls and buildings, developed at the University of Trieste. Numerical analysis of X-Lam wall systems using the FE model was carried out in order to extend the results of the experimental tests to different configurations of technical interest. Outcomes of the parametric study provided better understanding of the seismic behaviour and energy dissipation capacities of X-Lam wall systems. It was concluded that the numerical and analytical models, presented in this thesis, are a sound basis for determining the seismic response of cross-laminated timber buildings. However, future research is required to further verify and improve these prediction models.
XXV Ciclo
1985

Background and Purpose: The aim of this work is to present the idea of a short procurement chain of timber as a means to provide an increased value to Sardinian forests. It is based on the evidence that timber buildings are increasingly useful for a number of reasons including sustainability, the speed of erection, and excellent structural performance. However, most of the timber currently used in Sardinia is imported from outside this area. The idea is to use the best part of locally-grown trees to produce timber boards, while all the remaining part of the tree including the production waste is used as biomass for energy production. Important issues to address are the generally low mechanical properties of timber from locally-grown Sardinia trees such as Maritime Pine, which would make some wood-based products like glue-laminated timber not technically viable. Cross-laminated timber panels seems to be a possible solution to this problem because this wood-based product is manufactured in such a way that even with low-quality timber boards it is possible to obtain a medium quality panel. The panel is made of layers of timber boards with the adjacent layers glued under pressure at a right angle. Another issue is the need to grade the local timber, for which a number of specimens must be tested on destruction in order to identify a visual or a machine stress grading procedure. Last but not least, the panels must be tested on destruction to correlate their mechanical properties to the properties of the boards. Materials and Method: the research has been developed through the following steps: 1) two maritime pine plantations with stands suitable for logging and processing were identified, extensively surveyed and sampled. On selected standing trees, based on measurements taken at different heights, the first preliminary grading was applied by sorting for structural and energy use. 2) Trees were harvested by a local company and the logs were finally assorted based on their size and their external defects. 3) The logs were then transported to the local sawmill, where different boards size required to build the grading rules and to produce the CLT panels were cut. Each board was then subjected to a non-destructive measurement of the Modulus of Elasticity using acoustic tool for measuring stress wave velocity (Viscan-Microtec) 4). After kiln drying, the required boards (approximately 840) were subjected to non-destructive measurements of their physical properties (density, humidity, defects etc.) using the machine purposely developed by Microtec. The aim was the calibration of this machine in order to enable the machine strength grading of Sardinia maritime pine. 5) The required boards were visually characterized and then tested to destruction in order to measure their strength and correlate this values to the presence of defects such as knot diameters and positions, grain deviations, etc. 6) Based on the results of phases 4 and 5, the visual and machine based grading rule for Sardinia Maritime Pine have been developed. 7) By applying the newly developed grading rules, some boards 5 have been selected among the available ones and used for the production of some prototypes of CLT panels. 8) In order to determine the structural performance, 68 panel have been tested to destruction. Testing was carried out in accordance with EN 408 on specimens with a span to depth ratio equal to 18 to determine the bending strength and stiffness, and on specimens with span to depth ratio equal to 9 to determine the shear strength. A number of different methods exist for the analysis and design of CLT elements, including the Shear Analogy Method and the Mechanically Jointed Beams Theory (Gamma Method). These methods have been considered in this study and a relative comparison have been presented in order to determine which method is most suitable when considering CLT formed using Sardinian grown timber.. Results: It was found that Maritime Pine as structural material is limited by stiffness rather than strength or density. The effective bending stiffness of CLT is a measure of the material stiffness in relation to the cross sectional build-up of the panel. To be competitive on the market, a Sardinian CLT product will have to compete with imported CLT panels, which are usually made from C24 graded material (spruce). In most cases this is simply because the C24 material is widely available on the market rather than a specification from the designer. The performance of panels made of Maritime Pine boards has been compared directly with that of imported products, demonstrating that an increase in the Sardinian panel depth of just 15% is sufficient to match the stiffness of the imported panels, which is the most important design property. Conclusions: This work lays the foundation for the development of a short procurement chain of wood in Sardinia. The EDENSO project developed in parallel to this doctorate study is still in progress and further tests on maritime pine CLT panels are planned. A short procurement chain of timber is a possible means to create job opportunities and reduce depopulation, particularly important in some area of the island. By adding value to the forests by means of timber production used in prefabricated components employed in low-rise timber buildings, it is also possible to improve forest management and even extend forested areas, which have many positive effects on the environment, the landscape and the reduction of hydrogeological hazard.

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.

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

Cross-Laminated Timber (CLT) combines layers of dimension lumber in alternating grain direction to form a mass timber panel that can be used to create entire wall, floor and roof elements. The viability of CLT as an element to resist lateral forces from racking has been of great interest (Dujic et al. 2004, Blass and Fellmoser 2004, and Moosbrugger et al. 2006). However, most research to date has been conducted on full-scale wall panels connected with proprietary fasteners according to European Test Methods. Little research has focused on non-proprietary connections, including nails, bolts and lag screws. The behavior of CLT full-scale wall panels is dependent upon the individual connection properties including the panel-panel connections between adjoining CLT panels within the wall. The purpose of this research is to evaluate the behavior of three small-scale CLT connection configurations using non-proprietary fasteners. Three different connections -LVL surface spline with lag screws, half-lap joint with lag screws, and butt joint with a steel plate fastened with nails - were tested in both monotonic and cyclic tests. In all, 30 connection tests were conducted, with 15 monotonic test and 15 cyclic tests. Connection strength, stiffness, and ductility were recorded for each connection. Experimental values were compared to National Design Specification for Wood Construction, or NDS (AWC 2012) predictions for connection strength. Nailed steel plate connections yielded much greater loads and behaved in a more ductile manner than did the lag screwed connections. The surface spline and half-lap connections often failed in a catastrophic manner usually due to splitting of the spline and fastener failure. Experimental results were generally lower than predicted by the yield models for the surface spline and steel plate connections. The half-lap connection resulted in higher experimental results than predicted. A discussion of the connection strength for materials with a non-homogeneous grain direction is also included.
Master of Science

The aim of my master's thesis is a project of a new apartment building on a sloped site at a level of the documentation for the structure realization. The building is partly basement with four above-ground floor. Individual floors up recede and are roofed with flat roofs. The structural system of the basement part is made up of permanent shuttering and the above-ground part is made up wall of cross laminated timber construction panels KLH. The project of the building is in accordance with the development plan of Kopřivnice and with the current street built. The work puts great emphasis on layout including security of the construction in terms of statics, architecture, energy savings and safety at utilizing the structure.

Basic of this Diploma thesis is Civil construction in Kostelec nad Orlici, which is in a part of city, where is planning off-grid community housing. Part of off-grid community housing is considered a partially sistainable civil construction, serving both for cultural use through the club, for commercial purposes such as various salons (hairdresser, massage or shop), as well as for sports activities with the possibility of small refreshments, such as bouldering, climbing wall and exercise hall. Four sustainable (off-grid) familly houses, which aren´t the subject of this thesis, are considered. Object SO01 – Civil construction is designed as a partially basement, two floors. The shape of the object is designed as several blocks with different height levels. From a material point of view it is a wooden building from the system of large-format laminated wood panels (CLT). The basement is designed with a waterproof reinforced concrete so-called white tub and prefabricated ceiling panels SPIROLL. A facade is made of wooden cladding, cement-fiber boards or thin-layer silicone plaster. A roof of the object is partially flat (vegetation and walkable) and a shed roof with a slope of 5°. A dance hall and the rest of the club + exit is located in the basement. A sanitary facilities, a technical room and a main entry with reception is also located in the basement. Right in the middle of the building is a climbing wall that runs across all floors. To the right of the climbing wall is a shop, exercise hall and staircase. To the left side are a sanitary facilities, a boulder (low climbing wall) and separate staircase for a office space on the 2nd floor. Behind the climbing wall is a bistro with entry for a terrace and entry for the club. There are some establishments like a hairdresser, a cosmetic salon, a tattoo salon and a massage salon on the 2nd floor. There are an entrance to a terrace above the bistro and a staircase to an attic and to second terrace as well on the 2nd floo

O trabalho tem o objetivo de estabelecer diretrizes para projeto de painel maciço em madeira utilizando o princípio da laminação cruzada de modo similiar ao Cross Laminated Timber (CLT), porém adequado ao setor madeireiro paulista. Não obstante, pretende-se contribuir para a difusão do conhecimento sobre sistemas construtivos com painéis maciços e ampliar a discussão sobre possibilidades de utilização da madeira na habitação. Primeiramente, foi delimitado o escopo da pesquisa e justificados os motivos que levaram à sua proposição; também foram discutidos os principais fundamentos teóricos, conceituais e metodológicos nos quais se baseia o trabalho. A seguir, as principais características de diferentes tipos de painéis maciços de madeira utilizando o princípio da laminação cruzada foram pesquisadas. Foram levantadas informações sobre as características básicas e processo produtivo de 5 produtos diferentes: Mayr Melnhof Holz BSP, Novatop Solid, Massivholz Mauer, Holz 100 e Massiv Wand 5. Depois, foi desenvolvida uma análise comparativa entre o setor madeireiro na Áustria, país que atualmente concentra a maior produção de CLT na Europa Central, e no Estado de São Paulo, local no qual se pretende avaliar as possibilidades e limitações para produção dos painéis maciços em madeira. A análise comparativa foi dividida em duas etapas: na primeira etapa foram analisadas as reservas florestais e indústria madeireira austríaca e paulista; na segunda etapa foram elaboradas estimativas de custo para a produção de um elemento vertical constituído por núcleo maciço utilizando o princípio da laminação cruzada em Viena e na região metropolitana de São Paulo. Por fim, relacionando as características do produto e sua influência no processo produtivo com as possibilidades e limitações proporcionadas pelo setor madeireiro paulista, foram estabelecidas diretrizes para o projeto de um painel maciço em madeira que utilize o princípio da laminação cruzada. As diretrizes foram elaboradas dos pontos de vista da utilização da madeira, do desenho do painel e de sua adaptação ao setor madeireiro paulista. A seguir, foi desenvolvido uma proposta preliminar para desenho de painel maciço. As informações levantadas durante o desenvolvimento desta dissertação foram obtidas por meio de visita às fábricas, pesquisa em teses e publicações relacionadas e pesquisa na página de internet dos fabricantes dos produtos.
The work aims to establish guidelines for cross laminated solid timber panel design, suitable to the forestry industry in São Paulo. It intendeds to contribute for knowledge diffusion about this building system and enhancing the discussion on timber construction in Brazil. First, the research\'s scope was explained as well as its main questions, hypothesis and objectives. Then, the main features of different types of cross laminated solid timber panels and it\'s production process were analysed. Information on the basic features and production process of five different products were gathered: Mayr Melnhof Holz BSP, Novatop Solid, Massivholz Mauer, Holz 100 and MassiveWand 5. Hereafter, a comparative analysis between the forestry industry in Austria, currently the largest cross laminated timber producer in Central Europe, and the State of São Paulo was developed. The analysis was divided into two stages: in the first stage, forest reserves and timber industry in Austria and in the State of São Paulo were investigated; in the second stage, cost estimates for the production of a solid timber vertical element in Vienna and in the metropolitan area of São Paulo were developed. Finally, all the information gathered previously was used in order to establish design guidelines for cross laminated solid timber panel relating product\'s design influence on the production process and the possibilities and limitations offered by the forestry industry in São Paulo. The guidelines were developed from the point of view of timber utilisation, panel design and its adaptation to São Paulo\'s forestry industry. Then, a preliminary solid wood panel proposal has been developed as a way to synthesise the guidelines set previously.Information for the research was obtained through factory visits, theses and related publications and research on the manufactures website.

This diploma thesis deals with project energy efficient mountain chalet. The building is located in the Krkonoše national park, near by highest Czech mountain named Sněžka. Object is located on plot number 899 in the cadastral Pec pod Sněžkou, on the site of the initial ,,Giant” chalet. The aim of this thesis is proposal of energy efficient mountain chalet in extreme climate conditions, such as in the mountain area, at the elevation 1378 m. Proposal of the chalet emphasis is on achieving maximum energy self-sufficiency. The building consists of two objects SO 01 and SO 02 interconnected by the roof. The total built-up area is 191.39 square meters. The accommodation capacity is 20 people.

Single-storey C-shaped building of kindergarten in Nový Jičín with flat green roof.The building is situated on the flat land. The plot is accessible by local road. Kindergarted has irregular plan. The ends are connected by connecting tunnel, which is partly below ground level. Courtyard facade is a vertical garden - green facade.

“The right to one’s home” is a project that raises the issue of affordable housing, challenging this broad concept both in universal terms and later applied to specific condition of a site located in Warsaw, Poland. Beside the obviously economic dimension, affordability stretches out to urban politics by proposing new power relations and redefining neoliberal cities of today. By reclaiming centrally located, infrastructurally connected and potentially attractive sites it is a tool to counteract gentrification. Within the thesis, affordability is achieved with both organizational and spatial strategies – meaning that architectural solutions are accompanied by a simple administrative model that introduces different actors (municipality, private investors, housing cooperatives, non-profit organisations). Seeing the opportunity of reducing building cost in prefabrication, three panel systems were designed and placed on the site. Deriving from the history of concrete panels and shifting to more sustainable material – cross laminated timber – the author tried to reach harmonious balance between quantity, quality and affordability. The proposal was not radicalized with micro-apartments nor was intended to save on architectural values – on the contrary, individual and careful design of the outer skin that covers structural core was an important goal of the project. Standardised architectural solutions and organizational strategies on the municipal level were combined to enable socially sustainable housing environment.

The increasing demand for more sustainable construction has led to the development of new structural systems that include wood as building material. Cross laminated timber (CLT) has been identified as a potential system to address this need and to provide alternative options in the range of low- to medium-rise construction. The appeal in using CLT as a shearwall is driven by the combination of the rigid panels and small dimension fasteners, which allows for significant energy dissipation in the structure. However, there is currently no reliable analytical model to accurately predict the behaviour of multi-segment CLT shearwalls. The current study aims to develop an analytical model capable of predicting the elastic and plastic phases associated with the behaviour of multi-panel CLT shearwalls. The model describes the wall behaviour as a function of the connectors’ properties in terms of stiffness, strength and ductility. This dependency means that the only input required in the model is the behavioural parameters of the connections. The proposed model contains six cases with a total of 36 different failure mechanisms. Two final wall behaviours were developed, and it was found that behaviour (i.e. single wall) could be achieved if the yielding in the hold-down occurred prior to yielding in the panel joints. Inversely, the other behaviour (i.e. coupled panels) was achieved if the yielding in the vertical joint occur prior to yielding in the hold-down. The analytical model was validated using a numerical model, and the results of the comparison showed very close match between the two models. The study proposed simplified design provisions with the aim to optimize the walls ductility (CP behaviour) or strength and stiffness (SW behaviour).

The matter of the Horečky project is complex called Art in Horečky,which is complex strategy how to get the people interested in arts to the area. Project designs gallery, house for artist, artistic path in nature...

The goal of this master´s thesis is to design load bearing structure of a sports hall. The thesis is elaborated in two variants of the structure design of the sports hall for common types of sports (handball, footsal, tennis, volleyball, basketball). The ground plan dimension is 42 to 72 meters and the construction height is 8 meters. The construction is designed for the district of Brno city. In the structural anlysis there were the following main load bearing structural elements designed and examined: glue laminated timber truss, wood purlins, steel beams, rods and bracing, columns, which together with the transverse girders are linked and foot and anchoring. The selected variant is also further developed. Part of the work is drawing documentation of the choosen variant, disposition drawing and drawings of the selected details.