Dissertations / Theses: 'Timber construction'

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Hairstans, Robert. "Optimisation of timber platform frame construction." Thesis, Edinburgh Napier University, 2007. http://researchrepository.napier.ac.uk/Output/6041.

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Timber platform frame has evolved as an efficient method of construction for domestic dwellings and is experiencing continual growth in the UK due to it lending itself to off-site modem methods of construction (MMC), being environmentally efficient and exhibiting structural robustness. The challenge faced by the industry in the UK is to continue the evolutionary process such that the future demands of off-site MMC and regulatory changes are met. By conducting a study of the development of timber platform frame construction and reviewing the current and future requirements of the domestic dwelling construction market the challenges for the industry were highlighted. The business drivers of a timber platform frame manufacturer were considered and in conjunction with the information from the review an agenda of research programmes was derived. The objective of the research, although primarily from a structural timber engineering perspective, was to address the challenges faced by the industry employing a holistic approach with a view to implementing applied research. The UK procurement process for domestic dwelling construction is such that building layout is determined by architectural requirements. Building layout can have an adverse effect on structural stability and result in an inefficient system. A design review was conducted to determine the influencing factors which impinge upon system stability as a result of which recommendations for improvements were made. From the investigation the transfer of shear from a wall diaphragm to the foundation was deemed critical. Therefore, an experimental study was carried out which has resulted in an optimised specification. Further to this mathematical modelling techniques were used to demonstrate the impact that architectural layout has on stability, quantifying the financial penalty of inefficient layout and making recommendations to improve current designs. One of major priorities of the UK Government is to reduce climate change by implementing a low carbon economy with sustainable production and consumption; all with duty of care towards natural resources. Improvements to the Building Regulations (2006), in conjunction with other requirements, will result in wall U-values in domestic dwellings to be between 0.27 to 0.30W/m2K. To determine an efficient method of meeting the new regulations an all encompassing research programme was conducted with the primary function being to develop a sustainable method of achieving thermal efficiency. Another method of wall construction is Structural Insulated Panels (SIPs) and this option was reviewed. Initial work by Kermani (2005) on the structural performance of SIPs was extended to examine their racking characterisitcs with comparative studies to European and British structural codes of practice carried out. One of the key industry drivers which the review highlighted was the need for the implementation of lean technologies. The fabrication of flitch beams (timber-steel-timber sandwich configuration), used in cases of onerous load span conditions and limited depth of section, was improved through the implementation of a shot fired dowel connection method. To optimise the method of fabrication and achieve implementation an extensive laboratory study was carried out the results of which are compared to European structural codes of practice with recommendations made for design. The implementation of off-site MMC methods results in a change in associated risk during construction from minor consequence and high risk to major consequence and low risk. The crane erect method of timber platform frame construction optimises on-site performance in terms of both time and cost and reduces the requirement of working at height, which on average causes almost one fatality every week. The biggest health and safety risk associated with the crane erect method is failure of the roof system when being lifted into position. Using an analytical model, verified by full scale laboratory testing, a range of lifting conditions were researched and a best practice lifting procedure was developed which allows the safe lifting of standard roof systems used in domestic dwelling construction.

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Humphries, M. "Stability of timber trussed rafters." Thesis, University of Westminster, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378973.

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Gidlund, Anders. "The Diagrid : Adaptable housing with timber construction." Thesis, Umeå universitet, Arkitekthögskolan vid Umeå universitet, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171590.

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Sanna, Fausto. "Timber modern methods of construction : a comparative study." Thesis, Edinburgh Napier University, 2018. http://researchrepository.napier.ac.uk/Output/1256099.

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The doctoral research revolves around a comparative study of timber modern methods of construction for low-rise, residential buildings in Scotland. The building techniques studied involve both timber-frame panel construction (open-panel and closed-panel systems and structural insulated panels) and massive-timber construction (cross-laminated and nail-laminated timber panels). A non-timber technique is also included in the study: more traditional, load-bearing masonry (blockwork). These different building techniques have been analysed from two complementary aspects: environmental impacts and thermal performance. The environmental study is based on the life-cycle assessment methodology and embraces various aspects: environmental impacts (e.g., climate change, acidification, eutrophication, ozone depletion, etc.), consumption of energy (renewable and non-renewable resources) and production of waste (from non-hazardous to radioactive). The assessment takes a cradle-to-gate approach and, in its structure and method, is informed by the current recommendations of the international standards in the field (i.e., ISO 14040 series). Various environmental trade-offs between construction methods have been identified. In terms of global-warming potential (excluding biogenic carbon sequestration), results suggest that timber-frame buildings show a better performance than masonry buildings; this is particularly true for the open-panel system, which emits about 10% less carbon than the masonry counterpart. Massive-timber buildings tend to cause more carbon emissions than masonry ones. In terms of consumption of non-renewable primary energy, timber buildings do not generally show significant advantages with respect to blockwork-based masonry. In particular, structural-insulated panel systems tend to show very high energy requirements. Timber-based buildings show a tendency to cause increased acidification, eutrophication and creation of low ozone than their masonry counterpart. The level of offsite fabrication that is employed for the erection of the buildings plays an important role in the magnitude of most environmental impacts, which show an average decrease between 5% and 10% when some of the operations are shifted from the construction site to the factory. v The thermal study investigates the performance of the building envelope, and, in particular, of external walls, by means of tests whereby the thermal behaviour of a sample of walls (of full-size section) has been observed and measured over time. On the outside, the walls were exposed to real, natural weather variations throughout the summer. The study especially focuses on the time-dependent response of three different walling systems (which results from their individual cross-sectional arrangements of building components and the associated combination of heat-storage capacity and thermal resistance): a timber-framed wall, a cross-laminated-timber wall and a masonry wall. Thus, the main goal of the study was to characterise the thermal-inertia parameters of these walls. This type of thermal behaviour is related to the repercussions of global climate change at UK level, especially in terms of increase in solar irradiance and temperature, which requires an adaptation of the building-envelope such that it can perform well both during wintertime and summertime, by providing maximum indoor comfort with minimum economic and environmental costs from the construction and operation of buildings. The timber-framed wall possesses the greatest capacity to slow down the propagation of temperature waves from the outer surface to the inner surface (time lag), whereas the masonry wall performs best with respect to reducing the amplitude of temperature oscillation on the inner surface (decrement factor). The cross-laminated-timber wall exhibits intermediate values of both time lag and decrement factor, relative to the other two walls. Both the thermal and life-cycle assessment of the construction alternatives aim at assisting the design and decision-making process in the residential field and at suggesting areas that need to be addressed and improved, towards a coherent evolution of the building techniques included in this study and a step forward in the realisation of sustainable, low-rise dwellings.

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Höök, Matilda. "Timber volume element prefabrication : production and market aspects /." Luleå : Luleå tekniska universitet, 2005. http://epubl.ltu.se/1402-1757/2005/65/.

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Larsen, Alfred. "Risk minimization in Rts, with application to FFTT timber construction." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/51988.

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The risk posed to a structure from an earthquake may be minimized by changing the design characteristics of the structure to determine the optimal design. A risk measure, the mean value of the cost functions in this thesis, can be determined using reliability methods to construct a loss curve. This formulation includes the effect of uncertainty in all aspects of the cost, including construction and repair given an event. This risk model also requires no prior information to determine the mean cost and does not define a discrete “failure,” instead using a continuum of possible outcomes in determining the mean of the cost functions. The optimization model allows for different search directions and step sizes in the search for the minimum cost, with steepest descent and BFGS search directions currently implemented. These analyses are performed using the Rts software, which has the capability of performing the optimization, risk, and reliability analyses on input structural models. The functionality of risk minimization is demonstrated with two example structures, with the framework provided for a third. The first is an example previously solved in Rt, which confirms functionality of the implementations in Rts. The second model uses an analytical model of a single-storey timber-steel hybrid frame, which utilizes the novel structural “Finding the Forest Through the Trees” (FFTT) design concept that has been proposed in Vancouver and studied at UBC. The minimum mean cost of this structure, subject to the cost functions and structural simplification, was determined by optimizing two decision variables that represent the fundamental geometry of the frame. Optimization of this frame converged to one point throughout many analyses, utilizing both the steepest descent and BFGS search methods. Finally, the framework for a future 6-storey FFTT example was developed. This example is inspired from modern tall timber design concepts, which are discussed in a literature review and demonstrates unique features within Rts, including the deep parameterization and nested model structure.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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Smith, Tobias James. "Feasibility of Multi Storey Post-Tensioned Timber Buildings: Detailing, Cost and Construction." Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2008. http://hdl.handle.net/10092/2587.

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This thesis describes a feasibility study into the use of a new method of timber construction developed in New Zealand. This new method combines the use of an engineered wood product (Laminated Veneer Lumber) and post-tensioned ductile connections. Three case study buildings are presented in concrete, steel and timber all representing current design and construction practice. A fourth building, referred to as the “timber plus” structure, is also considered with the addition of timber architectural components. The case study timber building consists of two lateral resisting systems. In one direction post-tensioned LVL moment resisting frames are used, with post-tensioned cantilever walls in the orthogonal direction. Timber-concrete composite floor units are also used. The method of design and detailing of the timber building is shown with member sizes being found to be comparable to that of the concrete structure. Sub-assembly testing is performed on some key connections with excellent results. Construction time is evaluated and compared to the concrete structure with similar construction times being achieved. Finally the costs of the case study buildings are calculated and compared. The costing found the four options to be similar in price with the Timber and Timber plus buildings showing only a 6% and 11% increase in total cost respectively.

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Björnfot, Anders. "Modular long-span timber structures : a systematic framework for buildable construction." Licentiate thesis, Luleå tekniska universitet, Byggkonstruktion och -produktion, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26617.

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One of the identified reasons for the low amount of timber construction in Sweden is a general lack of knowledge about timber engineering and how timber can be used to its full advantage. One way for increased timber construction is the development of a cost-efficient and easy to comprehend building system. Efficiency in construction has recently been under hot debate following the success of lean production in the manufacturing industry. Therefore, the attention of construction has been directed towards the manufacturing industry in an attempt to learn successful methods. Three main principles, modularity, lean construction, and buildability, emerge as potentially useful in order to streamline construction. The aim of this research project is to create a knowledge- based framework for long-span timber construction. This framework should be able to store knowledge and experience about timber construction as well as aid in the design and production of buildable timber structures. A buildable structure is here defined as a structure constructed in competition with all other materials and sub-system choices, i.e., by this definition a constructed structure is buildable and therefore competitive. The research is based on a case study of the design and production of long- span timber structures performed at a Swedish design company. The case study includes interviews, and a survey of 60 constructed long-span timber structures. A literature review of the industrialisation principles reveals that modularity has been a key concept in the evolution of the manufacturing industry. Therefore, the long-span timber construction industry should emit a bottom-up view where product modularity guides the construction processes. A systematic framework, Experience Feedback System (EFS), is created to store buildable construction knowledge based on modularity. The EFS is based on two distinct systems; Experience Based System (EBS), and Construction Knowledge Database (CKD), connected by a feedback loop for buildable construction feedback. The EBS utilises neural network theory containing competitive knowledge and experience of long-span timber structures, providing aid in early design. The CKS is based on the Design Structure Matrix (DSM), providing management of innovative construction and aid in detailed design. Due to the adaptability of neural networks and the developed 3-D DSM hierarchy representing the structural system, the systematic framework is potentially useful for the design and development of other types of structures and materials choices in the future.
Godkänd; 2004; 20070128 (ysko)

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Björnfot, Anders. "Modular long-span timber structures: a systematic framework for buildable construction /." Luleå, 2004. http://epubl.luth.se/1402-1757/2004/034.

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Wong, Ricky Chin Wey. "Construction time and cost of multi-storey post-tensioned timber structures." Thesis, University of Canterbury. Department of Civil and Natural Resources Engineering, 2010. http://hdl.handle.net/10092/5256.

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The environmentally friendly and high performance multi-storey LVL timber system developed at the University of Canterbury (UC) consisting of post-tensioned frames and shear walls is referred to as the Pres-Lam system. It is possible that this structural system has the ability to increase productivity and reduce construction costs when compared with concrete and steel construction materials. As the Pres-Lam system is a new technology, the actual construction time and cost are still unknown. The outcome of this research will add value to the construction industry and encourage the industry to consider the Pres-Lam system for future projects. Previous research has shown that construction using this type of structural system is feasible for multi-storey buildings. In case study (1), this research revisited the research done for the actual Biological Sciences building under construction at the University of Canterbury based on the latest information available from the UC timber research team. This research compared the construction time and cost of three virtual buildings (Pres-Lam, Concrete and Steel) for Case Study (1). The research has been able to optimise the performance of the Pres-Lam system having increased open spaces with large column spacing. The proposed fully prefabricated double “T” timber concrete composite (TCC) floor system was used and found to reduce construction time. This has also shown that the LVL components in the Pres-lam system can be fully prefabricated at a factory. In case study (1), the predicted estimated construction time for the structural system was 60 working days (12 weeks) as compared to the concrete structure which required 83 working days. In the construction time analysis only the construction time of the structural building portion was compared instead of the overall construction time of the building project. The construction cost estimation for the concrete, steel and optimised Pres-Lam overall buildings including claddings and architectural fittings were produced and compared. The construction cost analysis concluded that the construction cost of the Pres-Lam building has been estimated to be only 3.3% more than the steel building and 4.6 % more than the concrete building. In case study (2), this research evaluated the deconstructability of the Pres-Lam system and found that the Pres-Lam system was potentially a very sustainable building material where 90% of the deconstructed materials can be recycled and reused to construct a new office building at the University of Canterbury. The reconstruction time of the STIC office building has been predicted to be 15 weeks and the estimated cost for the reconstruction to be $260,118. This will be used for future construction planning, monitoring and control.

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Huenefeld, Joshua. "A report on the effects of wind speed on timber construction." Kansas State University, 2012. http://hdl.handle.net/2097/13606.

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Master of Science
Department of Architectural Engineering
Kimberly Waggle Kramer
Main lateral force resisting systems (MLFRS) in timber buildings consist of two components: diaphragms and shear walls. Diaphragms are used to collect the shear induced by the lateral force at each of the levels. The shear is transferred from the diaphragms to the shear walls via plywood sheathing and connections. The shear walls transfer shear to the sill plate via plywood sheathing and then into the foundation via anchors. Two approaches for designing shear wall are: the segmented shear wall approach and the perforated shear wall approach. The segmented shear wall approach uses only full height segments to resist shear; each individual segment must be designed to resist the shear and overturning force induced by the lateral load. The perforated shear wall approach uses both full height segments and segments around openings to resist shear; the wall as a whole is used to resist shear and overturning forces induced by the lateral load. This report examines one-, two-, and three-story timber buildings located in three different wind regions: a) 115 mph, b) 140 mph, and c) 160 mph. This report presents the design process for the MLFRS components and a comparison of the designs for each of the buildings. The purpose of this report is to determine how the design changes depending on the magnitude of the lateral load, the height of the building, and the approach used to design the shear walls.

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Cichocka, Judyta M. (Judyta Maria). "INFRAME - design and construction of a sequentially erected elastic timber gridshell." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/129869.

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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, September, February, 2020
Cataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 79-81).
This thesis presents a design-oriented methodology for the design, optimization and construction of sequentially erected elastic timber gridshells. A multi-objective approach toward simultaneous optimization of the overall size and grid configurations is implemented to achieve maximum structural performance and minimize cost. The proposed methodology is applied to a 1:1 design of an open-air outdoor stage within the MIT campus. The design was certified compliant with the building regulations in the jurisdiction where it was constructed. The construction of the INFRAME pavilion brings a few insights towards the potential adaptation of bending-active systems to the building codes and presents a new application of temporary elastic timber gridshell structures for outdoor events.
by Judyta M. Cichocka.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering

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Fang, Demi L. "Timber joinery in modern construction: Mechanical behavior of wood-wood connections." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127868.

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Thesis: S.M. in Building Technology, Massachusetts Institute of Technology, Department of Architecture, May, 2020
Cataloged from the official PDF of thesis.
Includes bibliographical references (pages [107]-112).
Timber joinery is a method of geometrically interlocking timber elements prevalent in historic cultures around the world, including North America, Europe, and East Asia. The use of joinery as structural connections faded with the development of metallic screws and nails. Two recent developments offer the opportunity to revive this historic timber connection type: 1) the increasing desire to reduce embodied carbon in buildings by replacing more components with timber as a low-carbon structural material, and 2) recent digital fabrication capabilities which enable the precise milling of complex geometries as an alternative to the time- and labor-intensive handiwork required previously. How can joinery connections be designed in modern structural joints? Can we quantify the sustainability advantage of using these all-timber joints in lieu of the modern convention of metallic fasteners? This thesis addresses both questions as applied to the Japanese Nuki joinery type, though the workflows may be applied to any joinery geometry. First, the rotational stiffness of the Nuki joint is characterized and cross-verified using multiple methods. Second, the embodied carbon of a gravity frame using Nuki joints is compared to that of a gravity frame using conventional metallic fasteners. The use of Nuki joints not only eliminates the use of steel and aluminum but also provides rotational stiffnesses that enable smaller beam sections to be used. It is shown that gravity frames designed with Nuki joints could reduce embodied carbon by over 70% compared to gravity frames designed using conventional beam hanger connections. The findings make a case for all-timber joinery connections to be implemented as a sustainable alternative to conventional metallic connections used in modern timber construction.
by Demi L. Fang.
S.M. in Building Technology
S.M.inBuildingTechnology Massachusetts Institute of Technology, Department of Architecture

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Hacene-Djaballah, Nouri. "Floating floor attenuation of impact structure-borne sound in timber construction." Fairfax, VA : George Mason University, 2009. http://hdl.handle.net/1920/4598.

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Thesis (M.S.)--George Mason University, 2009.
Vita: p. 42. Thesis director: Girum Urgessa. Submitted in partial fulfillment of the requirements for the degree of Master of Science in Civil, Environmental, and Infrastructure Engineering. Title from PDF t.p. (viewed Oct. 12, 2009). Includes bibliographical references (p. 39-41). Also issued in print.

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Asif, Muhammad. "Life cycle assessment of aluminium-clad timber windows." Thesis, Edinburgh Napier University, 2002. http://researchrepository.napier.ac.uk/Output/2505.

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Over the last century a temperature rise of 0.6 C m global climate and the affiliated greenhouse effects have inflicted enormous impacts in the form of natural catastrophes, economical losses, health problems and seasonal disorder. If human activities continue at existing pace, a further temperature rise of 2.5 C is being anticipated over the next hundred years, which may cause unimaginable damage to humanity and ecology of the planet. In such a prevailing global environmental scenario sustainability is the need of hour and should be given the prime importance in execution of activities in all sectors in order to keep future secure for coming generations. Windows are amongst the most sensitive elements in a building envelope, also, due to their multi-disciplinary role, they are important not only for their effects on interior environment but also for the energy performance of the building. Energy contents and environmental impacts of the materials involved, add up on to window significance in the ecology of buildings. Energy efficient windows with least possible environmental burden over their whole life cycle are thus very important in achieving desired levels of sustainability in general, particularly in buildings. The present work addresses the sustainability of double glazed aluminium clad timber windows adopting the life cycle assessment (LCA) approach. LCA of windows helps cutting down the associated ecological burdens at all stages, i.e. extraction/production of materials, operation, maintenance and disposal of windows at the end of their service life. Cost effectiveness and productivity, the important features of sustainability, have been evaluated for aluminium clad timber and timber windows on the basis of life cycle cost assessment (LCCA) approach. Value engineering (VE) of aluminium clad timber windows has also been addressed. Running and/or maintenance costs which largely determine the life cycle costing have been estimated and the most cost effective options are presented. Four different types of windows, made of aluminium, aluminium clad timber, PVC and timber frame, have also been compared with respect to the ecology of frame materials - covering energy contents and environmental loads, maintenance and durability, service life and costing. A survey has been carried out with the help of housing authorities, architects and surveyors within UK, to study the performance of these windows in real life. A series of accelerated tests have been carried out to study the weathering performance of the candidate windows. The results have revealed that aluminium clad timber windows have excellent resistance against weathering conditions and they perform better than aluminium, PVC and timber windows under any conditions. In an ongoing research project at Napier, copper (Cu) coated silicon carbide (SiC) reinforcement particles have been used in aluminium 6061 matrix to enhance the mechanical properties of the Al SiC metal matrix composite (MMC), which is a prospective material to be used in window hardware. Results have indicated that Cu coating does not bring any additional corrosion loads onto the MMC. Recommendations for further work have also been laid out.

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Davies, Ivor. "Moisture conditions in external timber cladding : field trials and their design implications." Thesis, Edinburgh Napier University, 2011. http://researchrepository.napier.ac.uk/Output/4702.

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This thesis describes the development of technical guidance on timber facade design. The study involved a state-of-the-art review; an exposure trial of external cladding made from Sitka spruce (Picea sitchensis) and the production of construction details and associated information. It was undertaken because timber is an increasingly common cladding material in the UK, being used on low-rise residential buildings and for medium-rise and non-domestic buildings. The risks have, therefore, increased but this is not reflected in published guidance. Sitka spruce was used due to its availability in the UK and its similarity to Norway spruce (P. abies) which is widely used for cladding in Scandinavia. The exposure trial indicated that the moisture content range in timber facades is wider than accepted. The minimum moisture content of around 10% appears to be similar for all types of timber cladding and all species. The maximum appears to vary between species according to their fibre saturation point and is influenced by construction detailing and workmanship. A preliminary model of these interactions is proposed. From a theoretical standpoint, the moisture conditions observed in the trial mean that the (commonly quoted) mean moisture content is all but irrelevant. The mode is a more representative statistic as in most cases the data are skewed towards the fibre saturation point for the species concerned. Most detailing combinations had a moisture content near to the fibre saturation point throughout the winter. Sitka spruce is, therefore, only suitable as external cladding in the UK if preservative treated. Around 40 construction details were produced. They integrate, for the first time, all of the performance requirements applicable to low- and medium-rise timber facades in the UK. The work's key benefit is that the guidance arising from this study rationalises and improves facade design. Further research is, however, needed to validate the moisture content model and extend it to other timber species.

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Su, Shenzhi. "Structure-borne sound transmission through resiliently suspended ceilings in timber frame floors." Thesis, Edinburgh Napier University, 2009. http://researchrepository.napier.ac.uk/Output/6799.

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Resilient bars provide cheap, effective sound insulation. They are increasingly popular in timber floor/ceiling assemblies in the UK following the upgrading of Building Regulations requirements. However, the behaviour mechanisms providing resilient bars with their insulating properties are not well understood. The effects of specific detailed features on their performance are assumed or estimated empirically. Myths relating to property-performance correlation prevail among various product manufacturers. Previous experimental studies revealed either overall effect or only covered the stiffness in the vertical direction. Spring and rod models used elsewhere also failed to predict three-dimensional, asymmetrical facets of resilient bar behaviour. This research investigated the influence of various three-dimensional resilient bar features through examining hypotheses: resilient bars act as springs (either vertical, bending, cantilever or spring hinge), or stiffeners. As these hypotheses are associated with certain material and geometrical features, the results revealed each's influence and relative importance. Three types of test were designed: vibration transmission, apparent stiffness and modal tests. Two representative but distinctly different resilient bar products were chosen as test subjects, which covered the features of interest and involved controversies. Vibration transmission tests were conducted on a series of configurations based on small-scale structures, which could not only demonstrate overall performance but allow detailed parametric investigations. Apparent stiffness tests on small samples enable isolation of spring effects so that their individual contribution could be evaluated. Modal tests revealed how resilient bars modified the vibration modes of the attached plate. By synthesizing the data from the above three angles together with data in the literature, the influence of key features was inferred and evaluated. Mass-spring-mass modelling and statistical energy analysis were carried oout which enhanced understanding of the system's behaviour. The findings led to an optimised resilient bar design and a patentable acoustic hanger system. The latter was prototyped and tested on a floor/ceiling assembly. The results showed that it was more advantageous than current resilient bar systems.

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Khokhar, Aamir Muhammad. "The evaluation of shear properties of timber beams using torsion test method." Thesis, Edinburgh Napier University, 2011. http://researchrepository.napier.ac.uk/Output/4406.

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Greyling, Christian. "Rethinking the making of our buildings: A timber construction research and development facility in the Pretoria CBD." Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/78611.

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Architects use materials to express an idea, give form and create shelter for whatever the reason might be. The architect’s arsenal comprises five main materials: steel, concrete, masonry, glass and timber. When and how these materials are used is dictated by personal preference, public opinion, legislation, environmental aspects and availability. The use of timber in the South African built environment has not taken centre stage, yielding to superior materials such as concrete and steel. Nevertheless, a mass timber building not only offers ecological and environmental advantages, but also immense skill-based advantages mainly because timber allows for component manufacturing and assembly (Green, 2019). Recent approval by the South African Bureau of Standards (SABS, 2020) of engineered wood such as cross laminated timber (CLT) has sparked interest in developing a timber research facility completely built with wood in the Pretoria central business district (CBD). The high-tech construction of such a facility would utilise manufacturing methods like the integration of building information management (BIM) programs with computer numeral control (CNC) machines to enable unskilled workers to make a building instead of constructing the building. This dissertation aims to challenge local legislation around timber construction, empower unskilled workers to make complex/ large-scale buildings and change public opinion about timber construction, as well as to create a stronger timber culture in South Africa.
Mini Dissertation (MArch (Prof))--University of Pretoria, 2020.
Architecture
MArch (Prof)
Unrestricted

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Thomas, Robert Huw. "An innovative timber construction system : building affordable housing using homegrown Welsh softwood." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/45138/.

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This thesis tests an approach to delivering affordable housing for rural Wales, through the design and development of a system of homegrown, re-engineered timber components for self build. Recent studies and policy have demonstrated an acute shortage of affordable housing in rural Wales. Consequently, the Welsh Assembly Government has committed to deliver an additional 6,500 homes in the period 2007 - 11. However, there remains significant concern regarding the long term, sustainable delivery of affordable rural housing. This dissertation proposes a solution to this need, based on the readily available resource of homegrown softwood. Sitka Spruce has become the primary production crop of the Welsh woodlands. It is rarely used in the construction industry due to its propensity to distort and instead is utilised in low value industries, including low grade carcassing timber. It is proposed that through an innovative and radical approach, homegrown timber resources can offer a high quality, locally sourced and sustainable modern method of construction. In this study, a system of engineered homegrown timber components is designed, prototyped and tested as a self build construction solution for affordable housing in the diverse physical, social and economic context of rural Wales. Design led studies, including a ‘Pattern Book’ of house types, and realised prototypical constructions are used to inform and interrogate the proposed components and construction methodology. The primary objective of these investigations is to examine the applicability and appropriateness for self build construction. Finally, through the construction of a whole house prototype, a system of homegrown timber components and an approach to its assembly is proposed. Although limitations remain with this proposal, it has been possible to demonstrate that there is significant opportunity for an innovative, self build construction system using homegrown timber resources, to offer an efficient and sustainable solution for affordable housing in rural Wales.

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Smyth, Max. "A Study of the Viability of Cross Laminated Timber for Residential Construction." Thesis, KTH, Byggvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230994.

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This report presents an overview into cross laminated timber (CLT) as a construction material and how it compares to traditional methods of construction. CLT is also examined in the context of a move to off-site manufacturing (OSM) and a greater emphasis on sustainability in the construction sector. In this context it is found to perform well with mass timber products such as CLT being the only carbon negative building materials capable of building mid and high-rise buildings. The barriers and opportunities for CLT are explored looking at literature, industry reports and case studies. The main barriers to wider use of CLT still come from uncertainties around the material. Although they have been proven to not be a problem, worries over issues such as how it performs during fires and the lifetime of buildings persist. A lack of standardisation may be the primary cause for this as a range of products and specifications across different manufactures and countries creates confusion and means that each building needs to be individually specified. The opportunities identified for CLT include its carbon saving properties which could benefit governments wanting to reach their carbon reduction targets. In addition, the ability to use CLT on a wider range of sites such as unstable brownfield land and over service tunnels lends to its strength in aiding with urban densification. In terms of costs, these are found to be comparable to those of traditional construction methods with high material costs being offset by reduced foundations and construction time. CLT buildings do, however, face a premium in insurance costs. Transport costs, resulting from a concentrated production base in central Europe, also add a considerable amount to the overall cost of the finished product. This in turn encourages domestic production in countries outside of Europe. The possibilities for CLT in the UK residential construction market are investigated with a focus on mid-rise and high-rise flat construction as that is what the economics and material properties of CLT most lend itself to. Although CLT currently has a low market share of less than 0.1% of homes in this sector there is the potential for this to increase to 20-60% over time. The lower range of this estimate is not predicted to be reached before 2035 and this is also dependant on rising CLT production levels. The volume of timber that is needed to manufacture enough CLT to reach these increased construction volumes can be sourced sustainably from existing forests production in Europe and North America. In addition, the UK has enough excess timber harvesting capacity to provide for the entirety of CLT buildings in the UK, however, large scale domestic CLT production is required to make this a reality.

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Voth, Christopher Ray. "Lightweight sandwich panels using small-diameter timber wood-strands and recycled newsprint cores." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/c_voth_120609.pdf.

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Thesis (M.S. in civil engineering)--Washington State University, December 2009.
Title from PDF title page (viewed on Jan. 26, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references.

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Coste, Guillaume. "The assessment and applications of a new connector type for use in timber structural systems." Thesis, Edinburgh Napier University, 2010. http://researchrepository.napier.ac.uk/Output/4407.

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Lusambo, Edward. "Use of round timber in the construction of roof trusses for agricultural buildings." Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361573.

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Stutesman, Jonathan Harley. "Identifying the Economic Barriers to CLT Cost Estimation Among Building Construction Professionals." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/96712.

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Cross-laminated timbers (CLTs) are strong and lightweight structural building materials. CLTs are made from renewable wood resources and have significant economic potential as a new value-added product for the United States. However, market penetration has been obstructed by product affordability and lack of availability for use. Previous studies and projects have surveyed opinions of designers and contractors about the adoption of CLTs. No previous study was found that surveyed cost estimators, who serve the essential function of creating economic comparisons of alternative materials in commercial construction. CLTs are not included in these current cost estimation tools and software packages which may be limiting the potential use of CLT in construction. The purpose of this study was to discover if cost estimation is being used to make structural decisions potentially affecting the marketability of CLT use in construction and building design because of the ability to estimate CLTs adequately. Through the use of a survey, the re-designing of a building, and discussions with subject matter experts, this study examined the knowledge level of cross-laminated timbers of under-surveyed building construction professions and the relationship between cost estimation and structural material choices. Their responses are demonstrating the need for better cost estimation tools for cross-laminated timbers such as inclusion in the Construction Specifications Institute's classification systems in order for CLTs to become a more competitive product. The study concluded that cost estimation is important for CLT market development, because it is being used extensively in the construction industry.
Master of Science
Cross-laminated timbers (CLTs) are strong and lightweight structural building materials that also serve as a method of sequestering carbon rather than emitting carbon like more traditional construction materials. CLT construction is straightforward and quick to assemble, requiring minimal time and labor. CLTs are made from abundant and renewable wood resources and have significant economic potential as a job creator and as a new value-added product for the United States. However, market penetration has been obstructed by product affordability and lack of availability for use. Previous studies and projects have surveyed opinions of designers and contractors about CLT use. However, no previous study has been found that examined the opinions of cost estimators, who serve an essential function in providing economic comparisons of different construction systems for designers and building owners to select in the commercial construction area. CLTs are currently not included in these cost estimates, and this lack of information may be limiting the potential of this construction system. The purpose of this study was to discover if cost estimation is being used to make structural decisions potentially affecting the marketability of CLT use in construction and building design because of the ability to estimate CLTs adequately. Through the use of a survey and discussions with subject matter experts, this study examined the knowledge level of crosslaminated timbers of under-surveyed building construction professions and the relationship between cost estimation and structural material choices. They are demonstrating the need for better cost estimation tools for cross-laminated timbers such as inclusion in the Construction Specifications Institute’s classification systems in order for CLTs to become a more competitive product. Cost estimation is performed early in the design process before the structural material has been chosen. However, making cost estimates of CLT materials early in the design process is not a practical solution at this point due to the lack of cost data available. As an alternative solution, this project developed a design tool that is meant to accelerate the design process and allow companies to approach suppliers for quotes, which require mostly complete designs. While this is not a complete solution, if designs are made faster and more effortless, they should also be a more affordable investment for clients. 5 | Page Building construction professionals perceived CLT construction as too expensive, unavailable to the consumer, or unwanted by the client. It was found that the lack of data, due primarily to the material being new to the US construction industry, was a significant barrier to CLT cost estimation. The custom design of many previous CLT projects, due to the lack of CLT construction in the current building codes, limits the collection of standard CLT construction data. There is also an issue with the discrete sizes of CLT panels limiting their competitiveness. These barriers were identified in this study, and further research is needed to develop complete solutions.

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Porteous, Alexander. "The structural behaviour of timber joints made with fully overlapping nails." Thesis, Edinburgh Napier University, 2003. http://researchrepository.napier.ac.uk/Output/2787.

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An integrated programme of experimental and analytical work was carried out to evaluate the nonlinear semi-rigid characteristics of timber connections using fully overlapping nails subjected to short duration lateral loading and moment. The investigation is part of a continuing programme of research at Napier University into the behaviour of timberjoints using fully overlapping nails as the connecting Z -1 mechanism. The effects of the factors and material properties that influence the behaviour of nailed joints were addressed in a structured and controlled way allowing semi-empirical models to be developed for the lateral load behaviour of rnulti-nailed timber joints using steel and plywood gusset plates. A quality control procedure was established for the testing programme and consistent standards were applied to the preparation and testing work. The semi-empirical models that were developed included for the effect of timber density: crussept late material effect- nail strength; number of nails: nail diameter; row spacing and the effect of the moisture content in the timber. They covered joints assembled with and without a gap between the timber and the gusset plates and for joints assembled with steel gusset plates, the effect of the predrill size used in the gusset plate was also investigated. The model results compared very well with the results from tests, accurately predicting the non-linear behaviour of the joints up to failure. An extensive analytical and experimental study was carried out to investigate the moment-rotation behaviour of these types ofjoints. Two linear arýd four non-linear models were developed for each type of joint and the efficiencies of the models were compared to detennine the one that best simulated the joint behaviour. The linear models consistently underestimated the capacity of the joint, giving conservative results. The best solutions were obtained by applying the torsion formula used for steel connections and incorporating the nail behaviour models developed for the non-linear lateral load joints. Account was taken of the non-linear behaviour of the connection and alternative models using fixed and moveable centres of rotation were developed. Very good comparisons were achieved between these models and the test results. A detailed comparison was made between the behaviour of the joints using the lateral load displacement models and Eurocode 5 (EC5) and it was concluded that EC5 rules did not accurately simulate the behaviour of this type of joint. It was concluded that the nail spacing rules in the code did not apply to fully overlapping nails. A limit state design method based on the principles used in EC5 has been developed from the models for the design of joints using fully overlapping nails and subjected to lateral loading or moment. The semi-rigid behaviour of the joints was also investigated and it was concluded that to safely predict the response of structures assembled with fully, overlapping nails. the semi-rigid behaviour must be included for in the analysis procedure. Rigidity factors, end fixing moment reduction factors and the secant rotational stiffness coefficients for the joints were derived. It was also shown that where the analysis was limited to the serviceability limit state. a modified elastic method of analysis could be used and where it was beyond this state a non-linear method of analysis was required.

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Hameury, Stéphane. "The hygrothermal inertia of massive timber connstructions." Doctoral thesis, KTH, Byggvetenskap, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4200.

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The work presented in this Doctoral dissertation concerns the ability of heavy timber structures to passively reduce the fluctuations of the indoor temperature and of the indoor relative humidity, through the dynamic process of heat and moisture storage in wood. We make the hypothesis that the potential offered by the hygrothermal inertia of heavy timber structures is significant, and that it could provide a passive way of regulating the indoor climate. This ultimately could results in a decrease of the energy demand from the Heating, Ventilating and Air Conditioning systems. In this Thesis, the author tries to characterise and quantify the significance of the hygrothermal inertia providing by the heavy timber constructions. The experimental studies contain an in-situ measurement campaign carried out at the Vetenskapsstaden building located in Stockholm and erected in 2001. The results from the test campaign show that a heavy timber construction may contribute to buffer the indoor temperature. A direct quantification of the moisture stored in the wood structure is measured regarding the year-to-year indoor humidity fluctuations. It was however hardly possible to directly quantify the moisture storage potential offered by the structure regarding the day-to-day indoor relative humidity fluctuations because of the low sensitivity of the measuring technique used. In regard to the limitations noticed during the in-situ measurements, laboratory measurements were launched to develop new methods to determine the day-to-day hygric performances of wood exposed indoor. A new method based on the Magnetic Resonance Imaging technology was developed and is intended to provide information about the Moisture Buffer Value measured according to a NORDTEST protocol, and about the moisture distribution in wood with high spatial resolution. The Moisture Buffer Value of untreated Scots pine measured with this method is in accordance with the gravimetric method provided by the NORDTEST protocol. The Moisture Buffer Value of coated Scots pine was also investigated and it is normally assumed that any coatings will decrease the Moisture Buffering Capacity of the structure. The results show however that for specific coating such as waterborne alkali silicate coating, the Moisture Buffering Capacity of the structure may on the contrary be improved. At last, numerical simulations were carried out. They were based upon the extension of a modular simulation environment IDA ICE 3.0, with the implementation of a specific model for heat and moisture transport in a wood. The results obtained pinpoint the highly synergetic effects between the indoor moisture loads, the ventilation rate, the outdoor climate and the moisture interactions with the structure. The outcomes also show that the Moisture Buffering Capacity of a heavy timber structure is appreciable. The structure is able to even out substantially the day-to-day indoor relative humidity fluctuations for a certain range of ventilation rate.
QC 20100825

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Bailey, David. "A performance evaluation of mainstream timber framed and traditional masonry housing in the UK." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/33628/.

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Within the UK traditional masonry construction techniques are struggling to deliver the quantity and ecological quality of housing required by an ever increasing UK population. This research employs a case study review of a mainstream mixed timber frame and masonry housing development - Green Street, in order to explore the ecological viability of timber prefabrication as an alternative to the established masonry construction methods currently employed in the majority of British housing. Four houses of each construction type in the Green Street development were outfitted with a number of environmental monitoring sensors for continuous monitoring. In addition the study incorporates fabric testing in the form of air permeability testing, Co-heating analysis, thermography, and a life cycle analysis. Building Use Survey, project management and design team interviews and an industry questionnaire form the final part of the evaluation protocol. The study revealed that heating the timber dwellings ultimately required less energy per degree difference between inside and outside temperatures. During the summer the timber housing displays a greater diurnal temperature swing, while on average the temperature remains consistently lower than the masonry housing. The masonry housing was found to be both more air tight and exhibiting a lower heat loss coefficient, despite that, the performance gap between design and reality for space heating is less in the timber prefabricated housing. The life cycle analysis revealed that the timber walls have a lower impact on climate change. BUS methodology results found that construction type had little to no impact on occupants. The design team review highlighted the need for a greater level of prefabrication in timber housing to increase precision and work around a serious skills shortage. An industry questionnaire suggested that timber construction in the UK can often suffer from poor construction practice, predicated by a gap in specialized knowledge. The research concludes that in this instance, the timber prefabrication technique produced dwellings that perform ecologically on par with their masonry counterparts. In answering the research question, the evidence suggests that at this stage the technique would be better employed on a case by case basis and supported by specialists in timber fabrication, rather than implemented as a blanket alternative for existing masonry construction. Already a number of insights from this research have filtered into industry practice and will continue to better inform both industrial and academic partners in their decisions regarding the use of timber prefabrication in mainstream UK housing.

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Yeh, Yu-Hsiang. "Comparative life cycle assessment of multi-storey timber buildings." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-151947.

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The entire comparative estimation comprises four sections: 1. Embodied environmental implications of different structural systems of wooden buildings; 2. Embodied ecological efficiency of diverse constructions composed of various materials; 3. LCA of building models comprising equivalent thermal performance; 4. LCA of building models exhibiting similar seismic behaviour. First, the LCA results for thirty realised buildings are analysed based on the inventory of each project. This evaluation is intended to quantify and compare the embodied environmental burdens caused by different structural systems of timber houses. The second section is a comparative evaluation of the embodied ecological impacts caused by different materials, when used in the same construction. This study aims to investigate the ecological efficiency of various materials in the form of whole structures. With regard to making a compatible and reasonable LCA comparison, however, the appraisal needs a more scientific framework. In order to address this insufficiency, the third and fourth LCA studies are carried out. The third section involves various buildings made of different materials but providing equivalent thermal performance. Within this estimation, the thermal performance of a building is simply represented by the thermal inertia of its outer walls. Constructions composed of alternative envelopes are established and LCA based on the inventories of these structures are carried out. The fourth section examines three structures composed of three building materials but exhibiting similar seismic behaviour. In this study, the horizontal stiffness of the entire building against earthquakes indicates its seismic performance. The simulation develops alternative multi-storey buildings according to the seismic performance. The environmental impacts of the three buildings are quantified and compared. Both the third and fourth sections take the recycling scenarios into account. The impact of disposal after the end-of-life and the contribution from reuse and recovery are integrated into the overall impact assessment. Defining the system boundary and scope is essential for LCA studies. Normally, LCA framework refers to a ‘from-cradle-to-grave’ scenario, including the manufacturing, utilisation and dismantling phases. In the studies here, however, the estimation is focused on the production and recycling stages, without the results for utilisation and maintenance. This appraisal is the so-called ‘from-cradle-to-gate’ plus ‘from-gate-to-grave’ system. Compared to former research, this dissertation raises a couple of innovative contributions to the sustainability appraisals of constructions: 1. The scopes are focused on the structural part of buildings, considering the congruent system boundary for LCA. 2. A series of LCAs compare various building materials in the form of construction, integrating diverse aspects about buildings like thermal and seismic performance. 3. These LCAs are based on consistent prerequisites and make it possible to compare the results comprehensively. 4. In addition to embodied implications, these LCA quantify the contribution from material recycling. 5. This study divides the timber buildings according to their structural systems and estimates them individually
Die vergleichende Bewertung der Umweltleistung mehrgeschossiger Wohnbauten umfasst vier Abschnitte: 1. Ökologische Auswirkungen der Bereitstellung und Bearbeitung von Holz für verschiedene Tragsysteme; 2. Material- und herstellungsinduzierte (graue) Umwelteffizienz von verschiedenen Materialien und Bauweisen; 3. Ökobilanzierung von Gebäuden mit gleichen thermischen Eigenschaften; 4. Ökobilanzierung von Gebäuden mit ähnlichem seismischen Verhalten. Zunächst werden die Ergebnisse der Ökobilanz für dreißig realisierte Bauten auf der Grundlage der Sachbilanzen analysiert. Diese Auswertung vergleicht und quantifiziert die materialbezogene Umweltbelastung für verschiedene Tragsysteme mehrgeschossiger Wohnbauten aus Holz. Der zweite Abschnitt vergleicht die ökologischen Auswirkungen verschiedener Baustoffe, wobei jeweils der gleiche Konstruktionstyp zugrunde gelegt wird. Das Ziel dieser Studie ist die Untersuchung der Umwelteffizienz unterschiedlicher Materialien auf der Ebene der Gebäudeteile. In Hinblick auf die Kompatibilität und Plausibilität der Ökobilanz wird mit der dritten und vierten LCA ein einheitlicher Bewertungsansatz geschaffen. Der dritte Abschnitt handelt von verschiedenen Gebäudetypen mit gleichem Wärmestandard aber unterschiedlichen Baustoffen, wobei die Wärmeeffizienz vereinfachend durch den Wärmedurchgangswiderstand der Außenwände erfasst wird. Es werden Baukonstruktionen mit alternativen Gebäudehüllen entwickelt und auf der Grundlage der Sachbilanzen ökologisch bewertet. Der vierte Abschnitt untersucht drei Strukturen aus verschiedenen Baustoffen mit ähnlichem seismischen Verhalten. Diese Studie verwendet die horizontale Steifigkeit des Gebäudes gegen Erdbebenerschütterungen als Indikator für die seismische Leistungsfähigkeit. Auf der Basis dieses Indikators werden konstruktive Alternativen für mehrgeschossige Gebäuden entwickelt und deren Umweltwirkungen quantitativ ermittelt. Sowohl im dritten als auch im vierten Abschnitt werden unterschiedliche Recyclingszenarien berücksichtigt. Die Auswirkungen auf die Umwelt, die nach der Nutzungsdauer infolge der Abfallbeseitigung, des Materialrecycling oder die Wiederverwendung entstehen, werden in die gesamte Umweltwirkungsabschätzung integriert. Die Festlegung der Systemgrenzen und der Umfang der Betrachtung ist für die Ökobilanz unerlässlich. Normalerweise betrachten diese alle Lebenszyklusphasen eines Produkts, einschließlich Herstellung, Nutzung und Recyclings („from-cradle-to-grave“). Die hier betrachteten Untersuchungen beschränken sich jedoch auf die Phasen der Produktion und des Recyclings. Umweltauswirkungen infolge der Nutzung und Wartung des Gebäudes werden nicht berücksichtigt ( „from-cradle-to-gate“ und „from-gate-to-grave“). Im Vergleich mit früheren Forschungsergebnissen arbeitet diese Dissertation innovative Beiträge zur Umweltbewertung von Baukonstruktionen heraus: 1. Der Rahmen der Untersuchung erstreckt sich auf die Bauteile der Gebäudestruktur, was zu einer einheitlichen Systemgrenze für die Ökobilanzen führt. 2. Die Datenreihen der Ökobilanzen vergleichen verschiedenartige Baumaterialien auf der Ebene von Gebäudeteilen unter verschiedenen Aspekten. 3. Diesen Ökobilanzen liegen einheitliche Voraussetzungen zugrunde. Dadurch ist es möglich, die Ergebnisse umfassend zu vergleichen. 4. Neben den material- und herstellungsinduzierten Umweltauswirkungen quantifizieren diese Ökobilanzen direkt den Beitrag des Materialrecyclings. 5. Die Arbeit klassifiziert die mehrgeschossigen Holzbauten nach Tragsystemen und bewertet diese individuell

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Aparicio, German Walter Jr. "Holzbau : timber construction and material information exchanges for the design of complex geometrical structures." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59105.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2010.
Page 77 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 74).
In a universe made of bits where everything is continuously computing and nature itself is processing information everyday, what is it that our materials compute? Specifically, what are the bits of information registered within timber? More importantly, in this universe made of bits how do we design using this information and how do we imagine new buildings? This thesis explores the use of wood as a natural material in the design and construction of complex geometrical timber structures by capturing the natural curvature found in timber into digital data and building a framework for surface timber mapping as a design method. Key results include a detailed framework for translation, method for timber mapping and a prototype utilizing this method. Future steps include growth of timber structures and the use of living material in combination with typical timber construction methods for the design and construction of future buildings.
by German Walter Aparicio Jr.
S.M.

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Lundstedt, Karin. "Thermal stresses in load-bearing glass-timber components." Licentiate thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-25381.

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Thermal stresses can arise in glass used in architectonic realisations in buildings as a result of solar irradiation: that is, sunlight. The magnitude of these thermal stresses depends on the temperature conditions in the glass in terms of the temperature differences between warm and cold areas. The work described here has verified the existence and distribution of thermal stresses in glass, both theoretically and experimentally, in a load-bearing element made of glass and wood, when exposed to incident solar radiation and various degrees of shading. The finite element method was used in order to simulate the temperature distribution in the glass, together with the resulting associated thermal stresses. Parts of these model results were then compared with results and data from experimental investigations in a solar simulator. The experimental trials were carried out on a plain glass sheet and on a wood-framed glass sheet. This frame assembly saw the glass fitted in a wooden frame such that its edge was flush with the edges of the frame and therefore freely exposed to the surroundings. Two different grades of glass were analysed in the theoretical modelling and used in the experimental solar exposure: a clear glass, with a low absorption coefficient, and a tinted glass having a relatively high absorption coefficient. The experimental part of the work included two different finishes to the glass edge: as-cut, with no further attention, and cut and smoothed. The results from the finite element method calculations agree relatively well with the experimental results. When simulating the temperature values and distributions, the value of the coefficient of heat transfer is an important factor in determining the results. The coefficient can be given either a constant value, taken from a standard, or a calculated value that varies depending on the surface temperature and ambient temperature at every instant. For the clear glass with a low coefficient of absorption, the calculated temperatures did not differ significantly depending on which method had been used to provide a value for the coefficient of heat transfer. However, for the glass with a high coefficient of absorption, and when exposed to high solar intensity, a calculated value of coefficient of heat transfer should be used in order to arrive at relevant values of surface temperatures and stresses. Thermal tensile stresses have more effect on the total stress level than have stresses arising from typical in-service vertical loads.

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Zaccaro, Vito Lorenzo. "Timber-concrete hybrid innovations : A framework to evaluate economical and technical factors for the construction market." Thesis, KTH, Byggnadsmaterial, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210045.

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Nowadays, the focus of the construction market is on sustainability aspects, for which purpose, the employment of wood seems promising. Nevertheless, in countries having high potentiality like Sweden, the timber construction market finds difficulties in growing. The reason lies in the lack of standards for design and industrialization and on the strong competition of the concrete industry. The timber-concrete hybrid solution is presented in this study as a solution beneficial for both the timber and the concrete markets: the former would benefit of a pulling action towards standardization and larger market, while the latter would fulfil the environment-friendly requirements and better differentiate in the competitive landscape. Therefore, the objective of this thesis is to provide a framework to evaluate innovations in construction market, highlighting the characteristic issues related to the matching of timber and concrete constructions, and detecting the main economic and technical factors to help in the decision-making process. This framework will help to organize and evaluate all the information and the boundary conditions about the introduction of a concrete-timber hybrid construction solution, which eventually would enhance the timber construction market itself through a preliminary association with concrete market. Firstly, some consideration on the market areas and on the general perceptions towards the timber construction are presented; then, the focus is moved onto the dynamics of concrete and timber supply chains, highlighting similarities, diversities, and possible reciprocal benefits, to finally detect the market indicators to be considered for a decision-making path related to the timber-concrete hybrid construction. From the technical side, a conceptual design is proposed, considering the industrialization of such hybrid solution. Annex A shows how standardization and modularity of the products would enable compatibility and interchangeability between timber and concrete, on account of the open system within the construction market. Annex B displays a schematic picture of how the exploitation of timber and concrete’ properties, with the industrialization of these two materials, can be best employed for a hybrid building. A preliminary technical evaluation of the timber-concrete hybrid is carried out by dividing the building into modular units and focusing on the main systems (horizontal loadbearing system, vertical loadbearing system, external envelope, inner partitions), while making consideration on structural design, fire protection, building technology details, building service systems integration, construction plan, and costs. The innovations within the construction market are often hindered by the fear to undertake a high-risk project. The proposed framework allows to increase the awareness on the general factors to be evaluated, and to undertake a gradual adoption of the “new” timber construction solution. The key points underlying the whole timber-concrete hybrid problem are standardization and modularity, necessary for a quality-oriented production. Further studies need to be carried out with an applicative intent: application of the general framework to real cases and pilot projects; automatic tools for the design and construction optimization including economic and technical factors; innovative and original hybrid solutions, which better exploit the timber-concrete synergy.

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Marzec, Cindy, and Joachim Gustavsson. "VALUE STREAM MAPPING – A CASE STUDY OF CONSTRUCTION SUPPLY CHAINOF PREFABRICATED MASSIVE TIMBER FLOOR ELEMENT." Thesis, Växjö University, School of Management and Economics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-1606.

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The purpose of this Master Thesis is to study how the value stream mapping concept can be applied along the construction supply chain for prefabricated massive timber floor elements. Identification and qualification of waste are starting points to propose suggestions on how to reduce and/or eliminate them. In order to use the value stream mapping along the construction supply chain, pertinent data has been collected and analyzed. To conduct the value stream mapping, the first three steps of the lean thinking principles in construction have been followed. The first step aims at defining the customer and his value as well as the value for the delivery team and how it is specified in the product. The second step is based on identifying the value stream and this is done through defining the resources and activities needed to manufacture, deliver and install the floor elements. This is conducted by using the VSMM methodology. In addition the current practice should be standardized and key component suppliers should be defined and located. The third and last step identifies non-value adding activities, in other words waste and suggestions on how to remove and/or reduce waste have been reached. Wastes from product defects, transportation waste and waste of waiting were to be found in the construction supply chain. Propositions to reduce and/or eliminate wastes were to implement a more careful planning of the manufacturing process and production schedule, to apply lean production principles in the manufacturing facility and decrease and or eliminate storage time. The study made has shown that in the supply chain of massive timber floor elements at Limnologen there is a big potential to lower costs and increase customer value as value added-time accounted for only 2% of the total time.

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Kasbar, Mohamed. "Investigating the performance of the construction process of an 18-storey mass timber hybrid building." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61433.

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The use of mass timber in high rise construction is an innovation. Mass timber construction has influential benefits including a lower overall construction time, a lower environmental impact, the use of renewable resource and an improved aesthetics. Despite the mentioned benefits, mass timber is not the traditional material for low to mid-rise commercial, institutional and residential construction in Canada. This is partially due to the need to explore the efficiency of mass timber construction relative to traditional construction. Detailed quantitative documentation of successful construction projects assists organisations planning mass timber high-rise projects by understanding and quantifying the advantages to ensure the viability of the construction process. This research project aims to understand the performance of mass-timber construction in the context of a construction manager, particularly the time saved due to completion of structural and envelope systems early. The case study chosen for this thesis is the tallest mass timber hybrid building in the world: Tallwood House. The research team studied the project in a macro-level perspective to investigate the building elements as single entities. Moreover, a micro-level study focuses on the performance of every level of the following elements: mass timber structure, envelope cladding systems and cross-laminated timber drywall encapsulation. The macro-level study investigates: (1) The production rate of the various building elements, (2) The coordination between structural trades to build a heavily pre-fabricated building using a single crane, and (3) The labor efforts per discipline. Moreover, the micro-level study investigates: (4) The variability of productivity of all levels, (5) A statistical investigation of three factors on cross-laminated timber installation, (6) Schedule reliability of preliminary planned schedule relative to the construction schedule (actual progress), (7) Earned value analysis, and (8) Planned percent complete to study the reliability of weekly work plans relative to construction schedules. All metrics were validated by the senior project manager through a discussion and confirmation of the inputs, findings and conclusions drawn. The claimed contribution of this research is an advanced state of knowledge about mass timber by exploring the efficiency of the construction process.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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Bruce, Iain Stevenson. "Timber frame construction in North East Scotland : a century of precedent 1830's-1930's." Thesis, Robert Gordon University, 2007. http://hdl.handle.net/10059/642.

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This study was prompted by a natural inquisitiveness about the concentration of timber buildings in both Braemar on Deeside and Fochabers on Speyside, and the assumed association with the history of timber extraction in the respective river systems. Reinforced by childhood memories of timber buildings in other locations, the idea turned into an ironic quest for a Lost Tradition of Timber buildings in North East Scotland. The fieldwork provides both substantive and extensive material with 198 records of extant buildings, and archival research having produced evidence of 156 others. However, in a field characterised by transience and lack of documentation, this total cannot be considered definitive. Whilst the study presents a significant body of information about a Victorian interest in timber frame building not previously identified in the literature, the lack of any previous research in this area means that the work represents a phenomenon which is isolated both historically and culturally. The study adopts a taxonomic methodology and a selection of case studies offers a comparative analysis in which frame typologies and their characteristics are examined. The geographical area is illustrated in map 1 fieldwork buildings distribution map. This is structured on 10km transects and individual buildings identified numerically in a north to south sequence within these transects. Fieldwork specimens represent a diversity of both buildings and frame types, and the extensive use of timber buildings by the railway companies demonstrates they merely exploited an already established capability and knowledge for timber building and were not responsible for its introduction into the geographical area of study. It is clear that the majority of the fieldwork examples are of building types that would have been `modern' to the late 19th century with only dwellings, church buildings and mills having historic precedence. This aspect introduces the enigma of the antecedents of their construction methods, particularly in view of the parsimony of the contemporaneous literature. A total of four differing frame types have been identified and a previously unrecorded post and rail system is represented across all building types. This frame is described and illustrated in Chapter 3, Construction Types, and features in a comparative drawing of known historical frame designs not previously published. The identification of this frame and its extensive use is considered one of the main contributions of the study. The taxonomy is presented in terms of discrete building types as uncovered by the field study. This has revealed a considerable number of dwellings constructed by tradesmen for their own family's use, a structural elegance represented across the building types and an unexpected lack of agricultural buildings In an attempt to reduce the historical and cultural isolation of the survey data, the data is examined in a broader context, the availability and suitability of materials, the availability of knowledge and skills and prevailing socio-economic and cultural attitudes.

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36

Amigo, Jesus Menendez. "Optimisation of timber frame closed panel systems for low energy buildings." Thesis, Edinburgh Napier University, 2017. http://researchrepository.napier.ac.uk/Output/1035263.

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The United Kingdom published a legally binding document to reduce national greenhouse gas emissions by year 2020 up to 34% against the 1990 levels. This target also fulfils the Europe 2020 strategy of 20% carbon emission reductions by year 2020 (EC, 2010). Emissions due to space heating count for around 60% of the total domestic emissions (DCLG, 2012). The report “Rethinking Construction” published in 1998 emphasised the opportunities to improve the quality and efficiency of the UK construction sector (Egan, 1998). More recently, a framework has been published by the Government to tackle fuel poverty by building more energy efficient homes (DECC, 2015). In terms of energy performance, Passivhaus is recognised as one of the most energy efficient and researched construction standards which requires an exceptionally high-level of insulation and airtightness. Closed-panel timber frames are a relatively new system in UK with an opportunity for growth. These advanced panels are pre-fitted in the factory, reducing the on-site work. However, closed-panel systems present a more complex sole plate fixing detail which can have an undesirable long-term impact on the structural and thermal performance of the building. The work presented in this thesis investigates the structural considerations, racking performance, of timber frame closed panel systems for future building regulations. The thesis underlines the significance of structural stability, serviceability and detailing in relationship with long-term thermal efficiency and airtightness, according to Passivhaus standard. An experimental study was carried out to investigate the structural racking performance of advanced closed panel systems. A comparison was made between the behaviour of the timber frame panels and the analytical PD 6693-1. A set of different wall panel built-ups is presented for optimised Passivhaus design, including thermal bridge-free sole plate details. A timber frame racking software application was developed to optimise the structural design of shear walls. A parametric study was carried out with this tool to generate efficient timber frame wall design tables for different applied racking loads and U-values. The software application also allows for direct specification of robust sole plate base fixings and thermal bridge free details.

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Tomoi, Masatoshi. "Reliability-based design for Japanese timber structures using Canadian S-P-F dimension lumber." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30106.

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Reliability levels of Japanese 2x4 wood frame structures were evaluated using lumber property data derived from evaluation of Canadian Spruce-Pine-Fir dimension lumber. The evaluations were made using the "Standard for Limit States Design of Steel Structures (Draft)", which was newly published by the LRFD Subcommittee of Architectural Institute of Japan, and In-Grade Data obtained by a Canadian Wood Council research project. These analyses were implemented using the computer program "RELAN" developed by Dr. R.O. Foschi at UBC and Monte Carlo simulations. Reliability levels of current Japanese 2x4 wood frame structures were also evaluated. Recommendations were made to encourage the application of limit states design into existing Japanese design methods.
Forestry, Faculty of
Graduate

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Fallahi, Azadeh. "Innovation in hybrid mass timber high-rise construction : a case study of UBC’s Brock Commons project." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61365.

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With the advocacy for sustainable construction on the rise, use of timber as the main building material is being championed in large-scale construction projects. While the advancement of engineered timber products is addressing some issues that previously limited the use of wood in high-rise construction, there are still challenges such as fire and weather safety, code compliance and negative public perceptions. One main gap in the available resources is the lack of a comprehensive and detailed case study of a high-rise project with wood as the main construction material to capture constraints and innovations necessary in creating success, which has formed the direction of this research. This thesis is focused on documenting a case study of the Brock Commons project, an 18 storey, hybrid timber-concrete residential high-rise located at the University of British Columbia, Vancouver campus, which is the tallest hybrid timber building in the world. The overall research objective was to identify and document the delivery of this innovative project, with a specific emphasis on the innovations necessary to make timber high-rise construction successful and the use of VDC tools in the design and pre-construction process. The case study documents the project context, the design process, the business and industry drivers, and the motivation for construction. Moreover, it investigates the motivations for all stakeholders, identifies the challenges and constraints, and captures the innovative solutions that were utilized to ensure project success. The case study also documents the innovative use of VDC to support prefabrication and overall project coordination. Specifically, it investigates the role of the VDC integrators in the project, the paths of communications with the different project team members, and the inputs and outputs of each phase of design and construction. This research identified lessons learned that can be applied to other construction projects where timber is the main structural component and a heavy use of VDC and pre-fabrication is required. Use of timber and innovative methods in construction have been consistently rising in the past decade, and this research aims to provide a starting point for future efforts in mass timber high-rise construction.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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39

Bohlin, Pelle, and Olle Lindroth. "Moderna trä- och betongstommar i flerbostadshus : En teknisk jämförelse av ett fyravåningshus med två stomalternativ." Thesis, KTH, Byggteknik och design, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102025.

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Målet med detta arbete var att belysa skillnaderna mellan ett fyravåningshus med trä- respektive halvprefabricerad betongstomme ur ett tekniskt perspektiv för att utröna vilket stomalternativ som är att föredra. Faktorer som belystes var: Tjocklekar på bärverksdelar Längsta möjliga spännvidder Installationsmontering Elementmontering Grundstorlek Ljudisolerande förmåga Risk för fuktskador Branddimensionering Projekteringskomplexitet Bygghandlingar från ett befintligt flerbostadshus med trästomme erhölls och analyserades, och ett hus med likvärdig stomme av betong projekterades. Bärverket med halvprefabricerad betong dimensionerades efter rådande Eurokoder och detaljer utformades enligt gällande lagar och regler samt erkänd branschstandard. Ur de tekniska perspektiv som avhandlats i denna rapport väger fördelarna med betong något tyngre än träalternativets fördelar trots att egenskaperna i vissa hänseenden är mycket lika. Betongalternativet ger stora fördelar vad gäller brand och ljud och är samtidigt enklare att projektera, medan trä har sina fördelar i montering och grundläggning. Att välja en stomme av trä till ett flerbostadshus verkar också ha fördelar i de icke avhandlade aspekterna, t.ex. miljö och arbetsmiljö. För att uppfylla ljud-, brand- och fuktkrav i ett trähus krävs det avancerade byggsystem som innebär stor komplexitet i projekteringen vilket kräver ett nära samarbete mellan träprojektör och fabrikör.
The goal with thisdegree project was to highlight the differences between an apartment building with a timber frame and partly prefabricated concrete frame from a technical point of view to determine which alternative that is preferable. Highlighted factors were: Thicknesses of load-bearing parts The maximum length of floor structures Assembly of installations Assembly of the frame-parts Sound-insulating ability Moisture problems Dimension of fire-protection Project-complexity Construction documents from an existing apartment building with a timber frame were obtained and analyzed, and a concrete frame house with similar abilities was projected. The half-prefabricated concrete construction was designed with current eurocodes and details were designed according to laws, regulations and recognized industry standards. From the technical perspective that has been discussed in this report, the advantages with concrete frames are greater than the timber alternative, despite the fact that they in some aspects are very similar. The concrete option provides significant benefits in terms of fire and sound abilities and it is also easier to design, while the timber option has its advantages in assembly and foundation. Choosing a frame of timber to an apartment building also seems to have advantages in the environmental and work environmental aspects. To fulfill the sound, fire and moisture requirements which are needed in a timber house it requires advanced building system that involves complexity of the design which requires close cooperation between the constructional engineer and the manufacturer.

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Ng, Pui-ling Anna Laura. "Reduction of timber use in the Hong Kong construction industry to mitigate severe deforestation in tropical forests in Southeast Asia /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22284503.

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Robertson, Adam Blake. "A comparative life cycle assessment of mid-rise office building construction alternatives : laminated timber or reinforced concrete." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/36433.

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The objective of this project aimed to quantify and compare the environmental impacts associated with the construction of a mid-rise office building. Two alternative scenarios were considered; a traditional cast-in-place, reinforced concrete frame and a laminated timber hybrid design, which utilized engineered wood products including glulam and cross-laminated timber (CLT). The study boundary was cradle-to-gate and encompassed the structural support system and the building enclosure. A case study building; Discovery Place – Building 12, was selected to represent a typical five-storey office building constructed in North America. Floor plans, elevations, material quantities and design loads associated with the concrete-framed building design were obtained from issued-for-construction engineering drawings. A functionally equivalent, laminated timber design was then conceived, based on the requirements outlined in CAN/CSA-O86-01. Design values for locally produced CLT panels were established from in-house material testing results. A life cycle assessment of CLT, manufactured in British Columbia with mountain pine beetle killed wood, was developed based on primary inventory data collected from a pilot-scale manufacturing facility. Life cycle inventory and impact assessment data for building materials was obtained from secondary sources including BEES® 4.0, ATHENA® EcoCalculator, CORRIM, and the US LCI. TRACI, an impact assessment characterization methodology, was employed to translate inventory flows into environmental impact indicators. The environmental comparison of building design alternatives was based on 11 impact categories. The results concluded that the laminated timber building design was associated with a lower environmental footprint in 10 of 11 categories. At a minimum, the heavy timber design demonstrated a 14% improvement, when considering acidification potential. At a maximum, the timber design exhibited a global warming potential that was 71% less than the concrete design. Fossil fuel depletion was the only category where the concrete design was superior, displaying a 6% advantage over the timber scenario. The cumulative embodied energy of construction materials was also calculated; with results estimating energy contents of 116 and 66 terajoules for the timber and concrete designs, respectively. The concrete building acquired 20% of its energy from renewable sources, whereas in the timber-framed case, renewables accounted for over 60% of the combined feedstock and process energy.

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Lindholm, Jonatan, and Stefan Markus Reiterer. "Marketing innovative products in a conservative industry : A look at Cross-Laminated Timber." Thesis, Högskolan i Jönköping, Internationella Handelshögskolan, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-36659.

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Background: Previous experience with the construction industry tells us that it’s often conservative and slow to adopt changes or use radical new ideas. This is a problem faced by Cross-Laminated Timber (CLT), as it’s provides a new way of working with wooden construction, that is still unfamiliar to most companies. Marketing this new solution is therefore hard, especially since a lot of the public is still unsure about the qualities and properties of the product. Purpose: The purpose of this thesis is to identify the different selling points of CLT to see how this product can be marketed towards an audience that is still sceptical towards the wooden material. Method: Results are gathered with the help of an interview study with six different companies that all in some way worked with CLT. The results are then put through a grounded analysis. Conclusion: The results show us that the most important thing to do when marketing a product that few people know of, or are sceptical towards, is to make sure that information about the benefits of using the product gets out. The most important marketing point for CLT seems to be the environmental advantage compared to concrete and the speed of which buildings can be erected.

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Schirén, Whokko, and Trixie Swahn. "Vibrations in residential timber floors : A comparison between the current and the revised Eurocode 5." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-89293.

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The European standard Eurocode 5, a design method for timber structures,is currently under revision. In this study the draft for a reviseddesign method for vibrations in timber floors was compared to the currentmethod. The hypothesis of the thesis was that the revised designmethod might force some changes to the present construction practiceand that these changes may carry with them increased costs for the industry.Six common floor structures used in Sweden today were identifiedand for these floors design calculations were made according to the currentand the revised design method. It was checked whether the floorspassed the criteria in the two design methods and a comparison was madefor the only criterion which could be compared between the methods, thepoint load deflection. Floor structures could pass or fail the current designmethod based on two criteria, the point load deflection and the unitimpulse velocity response. All floors passed the current design methodexcept one which had a fundamental frequency below 8 Hz, because ofthe low frequency the current design method was not applicable to thefloor structure. In the revised design method the final result is a responsefactor and based on the response factor floors are given floor performancelevels. The seven step scale for the floor performance level go from I toVII where I is excellent and VII is unacceptable. All floor structures excepttwo achieved an acceptable floor performance level according to therevised design method. The two floors which failed were floors commonlyused in single family houses, they failed for a span length commonly usedtoday. A limited parametric study was performed where it was found thatthe modal mass used had a larger impact on the floor performance levelthan the mass per square meter included. For floors with a fundamentalfrequency above 8 Hz, including a higher mass per square meter resultedin a lower, i.e. better, response factor in all cases except one. For floorswith a fundamental frequency between 4.5 and 8 Hz, a higher mass resultedin a higher, i.e. worse, response factor. The study found that notall floor structures used in Sweden today are acceptable according to therevised design method therefore changes may have to be implemented andthese changes could result in an increased cost.

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Isik, Aydin. "Disassembly And Re-use Of Building Materials: A Case Study On Salvaged Timber Components." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1042431/index.pdf.

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The objective of this study was to investigate the feasibility of using salvaged timber from deconstructed buildings in Turkey. The intention was to show that the re-use of &lsquo
waste&rsquo
materials, while decreasing the cost of construction also preserves the environment from wasteful and extensive use of natural resources. It is hoped that the findings of such a study will encourage professionals to use second hand timber components in Turkey. In order to deal with the waste problem and to save our planet the re-use of construction materials from economic, environmental, social, and historic points of views should be pursued. This research incorporated information about the re-use of timber, including ongoing projects around the world, as reported by the International Council for Research and Innovation in Building Construction (CIB) Task Group on Deconstruction (TG39), a local survey of individuals, organizations, and businesses that are related to the recycling and reuse of building materials. Local deconstruction works, recovery and re-use of timber elements and components were investigated on the basis of information obtained from the demolition contractors in Bentderesi locality in Ankara, a salvaged materials market. iii Moreover the study aimed to observe how used timber components are recovered from a demolition project. By observing the demolition of a building the author was able to determine the problems in recovering timber with the least damage. The findings of the investigation indicated that the architects and the building industry can play an important role to increase recovery rates and conditions of used timber components in construction, considerably. Instead of using nails for timber joints bolted connections should be preferred since they allow demounting and re-use with minimum damage during the deconstruction process. At the same time defects in timber due to extensive and unnecessary nailing can also be avoided. The decision on type of deconstruction, time and cost estimation, worker ability and sensitivity during disassembly influence the success of deconstruction. Tools and machinery used both on the work site and in the UBMs selling area have direct effects on the condition of recovered materials.

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Ronstad, David, and Niklas Ek. "Study of glue-laminated timber connections with high fire resistance using expanded steel tubes." Thesis, Luleå tekniska universitet, Byggkonstruktion och brand, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-70788.

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A key factor regarding fire safety of timber buildings is the performance of connections between the structural elements, since this determines the load-carrying capacity of the structure. Traditional timber connections do generally perform poorly in a fire compared to surrounding parts since the joints often consist of exposed metal parts and cavities which locally decreases the fire resistance. This weakness does often lead to the appliance of gypsum which removes the aesthetic appearance of timber. Through an innovative timber connection design, the hope is that the failings at elevated temperature are changed from the connection itself to surrounding parts thus increasing the fire resistance to the limits of the connected components. Two types of glue-laminated timber connections have been built and tested at RISE facilities in Borås with the purpose to determine if these could withstand fire exposure for 90 minutes under load. The connections are assembled by expanding hollow steel tubes that clinches the members together and at the same time makes the steel tube yield against the inside of the pre-drilled hole. Pre-stresses are created in the connection during this process that avoids an initial slip if the connection is loaded, which is one of the reasons that this type of connections is suitable in earthquake-prone areas. The joint design results in a significantly increased rotational stiffness, moment capacity and embedded energy of the joint in comparison with conventional timber connections. One of the connections is designed to withstand moment forces. The specimen is built as a beam to beam connection that is subjected to a four-point bending test at both ambient and elevated temperature. The connection withstood 39.5 kNm in ambient temperature and failed after 87 minutes and 6 seconds of fire exposure under load. However, failure in elevated temperature did not occur within the connection, and visual inspection after the test indicated that the steel tubes still were in excellent condition. The connection is therefore expected to have been able to withstand 90 minutes of fire exposure. The other connection is designed to withstand shear-forces and is built as a column to beam connection that is tested at both room temperature and elevated temperature. The connection endured a maximum shear-force of 181.4 kN in ambient temperature, approximately 30 kN higher than previously performed test with identical setup, and failed after 113 minutes of fire exposure under load. The failure in elevated temperature did however not occur inside the connection. The testing is limited to unprotected connections consisting of glue-laminated timber which are tested in accordance with ISO 834.
En nyckelfaktor för brandsäkerheten i träbyggnader är prestandan hos förbanden mellan konstruktionselementen eftersom dessa bestämmer konstruktionens lastbärande kapacitet. Traditionella träförband har i allmänhet dåligt brandmotstånd i förhållande till omgivande delar, detta eftersom förbanden ofta består av exponerade metalldelar och kaviteter som lokalt försvagar brandmotståndet. Dessa svagheter motverkas ofta genom att montera gips vilket negativt påverkar träets estetiska utseende. Genom en innovativ konstruktion av träförband är hoppet att den svaga punkten vid förhöjd temperatur flyttas från själva anslutningen till omgivande delar, vilket ökar konstruktionens brandmotstånd genom att brandmotståndet då begränsas av prestandan hos de anslutna komponenterna. Två typer av limträförband har byggts och testats vid RISE-anläggningen i Borås med syfte att bestämma om dessa under belastning skulle kunna stå emot brandexponering under 90 minuter. Förbanden monteras genom att expandera ihåliga stålrör som klämmer samman elementen och samtidigt deformeras mot insidan av det förborrade hålet. Förspänningar skapas i förbandet under denna process som förhindrar en primär förskjutning om förbandet är lastat, vilket är en av anledningarna till att denna typ av anslutningar är lämpliga i jordbävningsbenägna områden. Denna konstruktion resulterar i en betydligt ökad rotationsstyvhet, momentkapacitet och inbäddad energi i jämförelse med konventionella träförband. En av anslutningarna är konstruerad för att motstå momentkrafter. Provkroppen är byggd som en balk-balkanslutning som utsätts för ett fyrapunkts böjningstest vid både rumstemperatur och förhöjd temperatur. Anslutningen klarade 39.5 kNm vid rumstemperatur och fallerade efter 87 minuter och 6 sekunder av belastning i förhöjda temperaturer. Brottet i förhöjd temperatur inträffade emellertid inte i anslutningen och den visuella inspektionen som utfördes efter testet indikerade att stålrören fortfarande var i utmärkt skick. Anslutningen bedöms därför ha kunnat motstå 90 minuters brandexponering. Det andra förbandet är konstruerat för att motstå tvärkrafter och är byggt som en pelare-balkanslutning som testas vid både rumstemperatur och förhöjd temperatur. Anslutningen klarade en maximal skjuvkraft på 181.4 kN vid rumstemperatur, cirka 30 kN högre än tidigare utfört test med identisk uppställning, och fallerade efter 113 minuters belastning i förhöjd temperatur. Brottet i förhöjd temperatur inträffade emellertid inte i själva anslutningen. Testerna är begränsade till oskyddade förband bestående av limträ som under brandpåverkan testas enligt ISO 834.

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46

Kochkin, Vladimir G. "Analysis and Testing of a Ready-to-Assemble Wood Framing System." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/35038.

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The concept of a ready-to-assemble kit fabricated in a factory and delivered to the customer is well known and commonly used by the furniture industry. In wood construction, the lack of a simple and reliable method of assembling the frame members creates a barrier to wide acceptance of prefabricated kit structures. This thesis focuses on a novel technology of assembling structural components of a wood frame using a metal nail plate connector (NPC). This technology was referred to as a ready-to-assemble (RTA) wood framing system. The RTA system simplifies the framing process and allows for rapid erection of a wood structural frame by a small nonprofessional crew. A 16 x 24 foot RTA building was constructed to demonstrate the feasibility of the RTA system concept. An effective assembly sequence was proposed and successfully implemented. The design procedure for the RTA buildings was presented. The lateral load path for the RTA building includes diaphragms and shear walls. The contribution of the RTA frame can be ignored from the lateral load analysis. This conclusion was validated for the diaphragms with aspect ratios up to 4:1. The finite element method was used to model the RTA structures. The models incorporated semi-rigid behavior of the NPC. An analytical model was developed to predict the nonlinear moment-rotation relationship of the NPC. The proposed model showed a good agreement (R2=0.98) with the experimental data. Tests were conducted to measure the load-drift response of the RTA shear walls.
Master of Science

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Cantrell, Randall. "An innovation and performance analysis of an underutilized resource : the adoption-diffusion process for small diameter roundwood (SDR) /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/5511.

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Ng, Pui-ling Anna Laura, and 吳佩玲. "Reduction of timber use in the Hong Kong construction industry to mitigate severe deforestation in tropical forests in Southeast Asia." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31260342.

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Frantz, Åsa. "Limnologen : Inblick i svenskt träbyggande." Thesis, Växjö University, School of Technology and Design, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-2053.

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I Sverige fanns, mellan 1874 och 1994, ett förbud mot att bygga bostadshus med fler än två våningar i trästomme. Under denna tid försvann större delen av hantverks- och ingenjörskunnandet och man fick därför börja från början då förbudet hävdes. Byggandet gick till en början trögt, men tog fart i och med regeringens nationella träbyggnadsstrategi och utvecklandet av byggande med massivträ i början av 2000-talet. Limnologen i Växjö är ett bra exempel på hur långt fram Sverige ligger i utvecklingen, men det pekar också på områden inom tekniken som behöver förbättras.

Den här uppsatsen behandlar översiktligt hur trähusbyggandet har sett ut i Sverige och beskriver sedan Limnologen med fokus på entreprenadform, stabilisering, brandskydd och akustik. Vidare beskrivs hur massivträtekniken har utvecklats och hur byggsystemet för massivträ har tagits fram.

Between 1874 and 1994, Swedish legislation limited the use of timber in load- bearing structures of residential buildings. The use of timber was prohibited in buildings of more than two storeys. During this period, much of the knowledge of the craftsmen and engineers was lost. Therefore, when legislation changed, there was a large need for regaining old and developing new knowledge in the field of timber construction and timber engineering. The number of multi- storey projects was not very large during the first years. Partly due to that the Swedish government developed a national strategy for the increased use of wood in construction in the beginning of the

21st century, progress was made in developing new techniques and the number of projects increased. The project Limnologen in Växjö is a good example of the current status of Swedish timber engineering, but also points to the fields where there is still some work to be done.

This essay reports briefly on the building of wooden houses in Sweden in general, and describes the project Limnologen in particular. Issues like type of contract, stabilization, fire protection and solutions to prevent sound from transmitting are dealt with. Also a description of the development of cross- laminated timber (CLT) and how concepts based on CLT have been developed is given.

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Johnsson, Ellinor, and Annie Malmqvist. "Uppföljning av träbyggnadsprojekt inom Växjö kommun." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-43826.

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Ett sekellångt förbud mot att bygga hus med trästomme högre än två våningar har gjort att värdefulla kunskaper om träbyggandet gått förlorat samtidigt som andra material istället etablerat sig på marknaden.För utvecklingen av flervåningshus i trä har Växjö blivit en förebild för andra städer i Sverige och resten av världen. Med denna studie vill författarna skapa en uppfattning om var i utvecklingen vi står idag samt tillvarata erfarenheter från fyra representativa projekt.Målet har varit att ta fram faktorer i produktionsprocessen som påverkar tid, kvalitet och ekonomi för flervåningshus i trä. Dessutom har det undersökts i vilken grad och på vilket sätt erfarenheter från tidigare projekt omsatts i senare projekt.Arbetet resulterar i ett antal punkter som är viktiga att ta ställning till vid en byggnation av flervåningshus med en träbaserad stomme. Dessa punkter berör bl a vad som behöver beaktas vid hög prefabriceringsgrad, varför och hur väderskydd bör användas samt hur sättningar påverkar en träbyggnad. Utvecklingen är starkt beroende av kontinuitet och av att fler hus av denna sort byggs. Detta skapar förutsättningar för att det skall gå snabbare och bli mindre kostsamt att bygga med trä.

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Dissertations / Theses on the topic 'Timber construction'

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