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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Cross Laminated Timber; Options for Improving the Long Term Production Line of CLT in New Zealand

Leslie, Samuel Richard January 2013 (has links)
XLam New Zealand Limited is the first company in New Zealand to manufacture Cross Laminated Timber (CLT); structural timber panels used for roof, floor and wall diaphragms in commercial and residential buildings. Commissioning of the factory began in April 2012, but it is not yet fully complete. The panels are currently being produced discretely rather than in a production line, and some plant is yet to be installed. It is important that procedures and control documents are implemented from the beginning in a new factory. This Project provides these, as well as recommendations to improve the long term production of CLT in New Zealand by developing: 1. A Quality Assurance (QA) Framework for the CLT manufacturing process. 2. A CLT Design Guide to aid engineers and architects in structural design using CLT. 3. A Health and Safety Framework to control hazards and develop a culture of health and safety within the factory. 4. A 10 year financial forecast model to analyse possible future expansion options for XLam. This Project has been prepared in partial fulfilment of the 2012 Master of Engineering Management (MEM) degree at the University of Canterbury – ENMG 606: Project.
2

Composting of Cross Laminated Timber (CLT) Sawdust

Bahsi-Kaya, Gulbahar 10 August 2018 (has links)
A three-month study evaluated composting of cross laminated timber (CLT) sawdust amended with 10% and 20% chicken litter. Moisture was provided by rainwater or deionized water depending on the precipitation. The contents in the containers were mixed once or twice a week for aeration. Samples were collected at 0, 45, and 90-day intervals to measure weight loss, moisture content, pH, compost maturity, microbial count, and carbon-to-nitrogen ratio. Results indicated that composted CLT with 20% chicken litter had much higher weight reduction than others at day 45 and 90. Treatments with 10% and 20% chicken litter had a higher initial pH than controls and showed a slow increase near to neutral 7 by day 90. The germination rate of radish seeds to measure the compost maturity showed that composted CLT with 20% chicken litter had significantly higher germination rate than the others at days 45 and 90. A greenhouse study of composted material showed also that the 20% treatment could be used as soil amendment due to its excellent C/N ratio but appears to be unsuitable for container media. Longer composting time is suggested for CLT sawdust to be cured and used for potting media.
3

Identifying the Economic Barriers to CLT Cost Estimation Among Building Construction Professionals

Stutesman, Jonathan Harley 04 February 2020 (has links)
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.
4

On Building: A Return of the Master Builder

Hilker, Jesse Kirtland 09 July 2019 (has links)
This project aims to chronicle the process of building from the architects point of view. Not mindless, mechanical tasks aimed at some economic goal; but tangible, thoughtful work towards an educational and philosophical desire. The desire to be a Master-Builder has fueled architects for centuries. It is a role that the common definition of Architect has all but forgotten. While in practice very few of us will continue this tradition, it is important that we not lose this fundamental aspect of building. To begin to fulfill oneself with this title, the path is very simple: build a building. That is what follows in this book. It is a chronological outline of the design and build of the New River Valley Train Observation Tower. An additional layer to this project is the inclusion of a variety of innovative building materials/techniques, particularity the use of hardwood cross-laminated timber (CLT). This building will serve as an ongoing research opportunity to evaluate the conditions of building with this material in an extreme condition, complete exposure to weather. No work of architecture is a solo endeavor, yet my heavy involvement in the design, documentation, and building of the tower has culminated in a body of work that is distinctly my own. My role was that of a project manager, and I reported to faculty Kay Edge, Edward Becker, and Robert Riggs. This structure allowed me to have a great deal of independence, while vetting my drawings and ideas with experienced professionals. A small group of students joined me in the larger aspects of the build, which provided another opportunity to discover an aspect so critical to building: collaboration. This build taught so much about project management, design, and realization that could only be understood through such a physical experience. / Master of Architecture / This project aims to chronicle the process of building from the architects point of view. Not mindless, mechanical tasks aimed at some economic goal; but tangible, thoughtful work towards an educational and philosophical desire. The desire to be a Master-Builder has fueled architects for centuries. It is a role that the common definition of Architect has all but forgotten. While in practice very few of us will continue this tradition, it is important that we not lose this fundamental aspect of building. To begin to fulfill oneself with this title, the path is very simple: build a building. That is what follows in this book. It is a chronological outline of the design and build of the New River Valley Train Observation Tower. An additional layer to this project is the inclusion of a variety of innovative building materials/techniques, particularity the use of hardwood cross-laminated timber (CLT). This building will serve as an ongoing research opportunity to evaluate the conditions of building with this material in an extreme condition, complete exposure to weather. No work of architecture is a solo endeavor, yet my heavy involvement in the design, documentation, and building of the tower has culminated in a body of work that is distinctly my own. My role was that of a project manager, and I reported to faculty Kay Edge, Edward Becker, and Robert Riggs. This structure allowed me to have a great deal of independence, while vetting my drawings and ideas with experienced professionals. A small group of students joined me in the larger aspects of the build, which provided another opportunity to discover an aspect so critical to building: collaboration. This build taught so much about project management, design, and realization that could only be understood through such a physical experience.
5

Metodologia para estudo da caracterização estrutural de painéis de madeira laminada colada cruzada / Methodology for the study of structural characterization of wood panels of cross laminated timber (CLT)

Pereira, Marcos Cesar de Moraes 30 January 2015 (has links)
O CLT (Cross Laminated Timber) ou MLCC (Madeira Laminada Colada Cruzada) é um painel compósito estrutural formado por lamelas de madeira unidas com adesivos próprios para uso estrutural, com as camadas montadas de maneira perpendicular à camada anterior. É utilizado como elemento estrutural principal em edificações térreas e multipavimentos por ter características estruturais semelhantes ao concreto armado. Os objetivos gerais deste trabalho foram desenvolver uma metodologia de ensaios para a caracterização estrutural de painéis de MLCC visando a contribuição para a normatização do produto no Brasil e o estudo da rigidez de um painel modelo. Foi fabricado um painel com dimensões estruturais utilizando madeira de Pinus elliotti e adesivo estrutural à base de melamina-ureia formaldeído. Os ensaios mecânicos realizados foram adequados para caracterização estrutural de painéis de MLCC e podem compor uma futura normatização. Os valores de rigidez para o painel avaliado apresentaram módulo de elasticidade abaixo dos especificados pela norma americana ANSI/APA PGR 320 e pela especificação técnica europeia ETA06/0138, porém os módulos de rigidez do rolling shear e de compressão obtiveram valores similares aos recomendados. / The CLT (Cross Laminated Timber) is a structural composite panel formed by wooden slats together with own stickers for structural use, with the layers mounted perpendicular to the previous layer. It is used as the main structural element in single-story buildings with one or more floors for having structural features similar to reinforced concrete. The aims of this study were to develop a test methodology for structural characterization of MLCC panels aimed at contributing to the standardization of the product in Brazil and the study of rigidity of a panel model. A panel with structural dimensions using wood of Pinus elliotti and structural adhesive melamine urea formaldehyde base was manufactured. The mechanical tests were suitable for structural characterization of MLCC panels and can compose a future standardization. The stiffness values reported for the modulus of elasticity panel presented below specified by the US standard ANSI/APA PGR 320 and the European Technical Specification ETA06/0138, but the stiffness of the rolling shear and compression modules obtained similar to recommended values.
6

Metodologia para estudo da caracterização estrutural de painéis de madeira laminada colada cruzada / Methodology for the study of structural characterization of wood panels of cross laminated timber (CLT)

Marcos Cesar de Moraes Pereira 30 January 2015 (has links)
O CLT (Cross Laminated Timber) ou MLCC (Madeira Laminada Colada Cruzada) é um painel compósito estrutural formado por lamelas de madeira unidas com adesivos próprios para uso estrutural, com as camadas montadas de maneira perpendicular à camada anterior. É utilizado como elemento estrutural principal em edificações térreas e multipavimentos por ter características estruturais semelhantes ao concreto armado. Os objetivos gerais deste trabalho foram desenvolver uma metodologia de ensaios para a caracterização estrutural de painéis de MLCC visando a contribuição para a normatização do produto no Brasil e o estudo da rigidez de um painel modelo. Foi fabricado um painel com dimensões estruturais utilizando madeira de Pinus elliotti e adesivo estrutural à base de melamina-ureia formaldeído. Os ensaios mecânicos realizados foram adequados para caracterização estrutural de painéis de MLCC e podem compor uma futura normatização. Os valores de rigidez para o painel avaliado apresentaram módulo de elasticidade abaixo dos especificados pela norma americana ANSI/APA PGR 320 e pela especificação técnica europeia ETA06/0138, porém os módulos de rigidez do rolling shear e de compressão obtiveram valores similares aos recomendados. / The CLT (Cross Laminated Timber) is a structural composite panel formed by wooden slats together with own stickers for structural use, with the layers mounted perpendicular to the previous layer. It is used as the main structural element in single-story buildings with one or more floors for having structural features similar to reinforced concrete. The aims of this study were to develop a test methodology for structural characterization of MLCC panels aimed at contributing to the standardization of the product in Brazil and the study of rigidity of a panel model. A panel with structural dimensions using wood of Pinus elliotti and structural adhesive melamine urea formaldehyde base was manufactured. The mechanical tests were suitable for structural characterization of MLCC panels and can compose a future standardization. The stiffness values reported for the modulus of elasticity panel presented below specified by the US standard ANSI/APA PGR 320 and the European Technical Specification ETA06/0138, but the stiffness of the rolling shear and compression modules obtained similar to recommended values.
7

Seismic Design of Core-Wall Systems for Multi-Storey Timber Buildings

Dunbar, Andrew James McLean January 2014 (has links)
This thesis discusses the results of experimental tests on two post-tensioned timber core-walls, tested under bi-directional quasi-static seismic loading. The half-scale two-storey test specimens included a stair with half-flight landings. Multi-storey timber structures are becoming increasingly desirable for architects and building owners due to their aesthetic and environmental benefits. In addition, there is increasing public pressure to have low damage structural systems with minimal business interruption after a moderate to severe seismic event. Timber has been used extensively for low-rise residential structures in the past, but has been utilised much less for multi-storey structures, traditionally limited to residential type building layouts which use light timber framing and include many walls to form a lateral load resisting system. This is undesirable for multi-storey commercial buildings which need large open spaces providing building owners with versatility in their desired floor plan. The use of Cross-Laminated Timber (CLT) panels for multi-storey timber buildings is gaining popularity throughout the world, especially for residential construction. Previous experimental testing has been done on the in-plane behaviour of single and coupled post-tensioned timber walls at the University of Canterbury and elsewhere. However, there has been very little research done on the 3D behaviour of timber walls that are orthogonal to each other and no research to date into post-tensioned CLT walls. The “high seismic option” consisted of full height post-tensioned CLT walls coupled with energy dissipating U-shaped Flexural Plates (UFPs) attached at the vertical joints between coupled wall panels and between wall panels and the steel corner columns. An alternative “low seismic option” consisted of post-tensioned CLT panels connected by screws, to provide a semi-rigid connection, allowing relative movement between the panels, producing some level of frictional energy dissipation.
8

Combined glued laminated timber using hardwood and softwood lamellas

Muraleedharan, Aishwarya, Markus Reiterer, Stefan January 2016 (has links)
In this thesis, the behaviour of glued laminated timber combined with hardwood and softwood lamallae is investigated. The influence of hardwood in the tension and compression zone, in terms of strength and stiffness is evaluated.The basis of evaluation consists of determining the behaviour of beams with various combinations of hardwood solely in the tension zone along with beams with hardwood in the tension and compression zone. The influence of different amount of hardwood for both cases is studied my means of experimental and analytical methods.Experimental data attained by performing bending tests are evaluated for different combinations made from spruce and oak. By comparing the experimental and analytical data an increase in the strength and stiffness in various combinations is observed and potrayed which varies based on different wood species.
9

Estudo de emendas dentadas em Madeira Laminada Colada (MLC): avaliação de método de ensaio / not available

Macêdo, Alcebíades Negrão 20 September 1996 (has links)
Este trabalho consiste no estudo teórico e experimental das emendas dentadas em madeira laminada colada (MLC), cujo objetivo principal é avaliar o método proposto no Projeto da Nova Norma Brasileira PNBR 7190 (1996) para a caracterização da MLC, com ênfase às emendas dentadas. As espécies de madeira estudadas foram o Pinus elliottii e o Eucalipto grandis e o adesivo utilizado foi o CASCOPHEN RS-216, à base de resorcinol, produzido pela Alba Química Indústria e Comércio Ltda. A emenda dentada usada no estudo foi a correspondente ao comprimento de 20 mm da DIN 68140, geometria esta adotada pelo parque produtor de MLC no país. Nos ensaios são avaliadas as resistências ao cisalhamento na lâmina de cola, a tração normal à lâmina de cola e a resistência a tração das emendas dentadas. O desempenho das ligações foi avaliado em função da relação entre os valores obtidos nos ensaios com madeira colada e madeira maciça, bem como pelo modo de ruptura dos mesmos. Como conclusão obteve-se que o processo de colagem adotado foi bem sucedido para todos as amostras de caracterização da MLC, independente da espécie de madeira e do tipo de ruptura obtido. O método proposto no Projeto da Nova Norma Brasileira PNBR 7190 (1996) mostrou-se adequado para a caracterização das propriedades de resistência da MLC. / This work consist in the theoretical and experimental study of finger joints in glued laminated timber (GLULAM), with main objective to evaluate the method proposed in the New Brazilian Draft Code PNBR 7190 (1996) to characterization of GLULAM, with emphasis to finger joints. The species of wood studied were the Pinus elliottii and Eucalipto grandis and the adhesive was the CASCOPHEN RS-216, resorcinol-based, produced by Alba Química Indústria e Comércio Ltda. The geometry of finger joint used in the study was the correspondent to DIN 68140, this is the adopted by producer park of GLULAM in the country. In the tests were evaluated the shear resistance of glue lamina, the perpendicular tension resistance of glue lamina and parallel to grain tension resistance of finger joints. The performance of jointing was evaluated as a function of the relation between the values obtained in the tests with glued wood and clear wood, as well as rupture mode. Concluding remarks that gluing process adopted was well successful to all specimens of wood specie and rupture mode. The method proposed by New Brazilian Draft Code PNBR 7190 (1996) is adequate to characterization of the resistance properties of GLULAM.
10

Estudo de emendas dentadas em Madeira Laminada Colada (MLC): avaliação de método de ensaio / not available

Alcebíades Negrão Macêdo 20 September 1996 (has links)
Este trabalho consiste no estudo teórico e experimental das emendas dentadas em madeira laminada colada (MLC), cujo objetivo principal é avaliar o método proposto no Projeto da Nova Norma Brasileira PNBR 7190 (1996) para a caracterização da MLC, com ênfase às emendas dentadas. As espécies de madeira estudadas foram o Pinus elliottii e o Eucalipto grandis e o adesivo utilizado foi o CASCOPHEN RS-216, à base de resorcinol, produzido pela Alba Química Indústria e Comércio Ltda. A emenda dentada usada no estudo foi a correspondente ao comprimento de 20 mm da DIN 68140, geometria esta adotada pelo parque produtor de MLC no país. Nos ensaios são avaliadas as resistências ao cisalhamento na lâmina de cola, a tração normal à lâmina de cola e a resistência a tração das emendas dentadas. O desempenho das ligações foi avaliado em função da relação entre os valores obtidos nos ensaios com madeira colada e madeira maciça, bem como pelo modo de ruptura dos mesmos. Como conclusão obteve-se que o processo de colagem adotado foi bem sucedido para todos as amostras de caracterização da MLC, independente da espécie de madeira e do tipo de ruptura obtido. O método proposto no Projeto da Nova Norma Brasileira PNBR 7190 (1996) mostrou-se adequado para a caracterização das propriedades de resistência da MLC. / This work consist in the theoretical and experimental study of finger joints in glued laminated timber (GLULAM), with main objective to evaluate the method proposed in the New Brazilian Draft Code PNBR 7190 (1996) to characterization of GLULAM, with emphasis to finger joints. The species of wood studied were the Pinus elliottii and Eucalipto grandis and the adhesive was the CASCOPHEN RS-216, resorcinol-based, produced by Alba Química Indústria e Comércio Ltda. The geometry of finger joint used in the study was the correspondent to DIN 68140, this is the adopted by producer park of GLULAM in the country. In the tests were evaluated the shear resistance of glue lamina, the perpendicular tension resistance of glue lamina and parallel to grain tension resistance of finger joints. The performance of jointing was evaluated as a function of the relation between the values obtained in the tests with glued wood and clear wood, as well as rupture mode. Concluding remarks that gluing process adopted was well successful to all specimens of wood specie and rupture mode. The method proposed by New Brazilian Draft Code PNBR 7190 (1996) is adequate to characterization of the resistance properties of GLULAM.

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