Spelling suggestions: "subject:"cross - laminated timber"" "subject:"gross - laminated timber""
1 |
Cross Laminated Timber; Options for Improving the Long Term Production Line of CLT in New ZealandLeslie, 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) SawdustBahsi-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 ProfessionalsStutesman, 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 BuilderHilker, 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 BuildingsDunbar, 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 |
Možnosti výstavby z masivních vrstvených materiálůCrhonek, Vladimír January 2010 (has links)
No description available.
|
9 |
Effect of Realistic Boundary Conditions on the Behaviour of Cross-Laminated Timber Elements Subjected to Simulated Blast LoadsCote, Dominic January 2017 (has links)
Cross-laminated timber (CLT) is an emerging engineered wood product in North America. Past research effort to establish the behaviour of CLT under extreme loading conditions has focussed CLT slabs with idealized simply-supported boundary conditions. Connections between the wall and the floor systems above and below are critical to fully describing the overall behaviour of CLT structures when subjected to blast loads. The current study investigates the effects of “realistic” boundary conditions on the behaviour of cross-laminated timber walls when subjected to simulated out-of-plane blast loads.
The methodology followed in the current research consists of experimental and analytical components. The experimental component was conducted in the Blast Research Laboratory at the University of Ottawa, where shock waves were applied to the specimens. Configurations with seismic detailing were considered, in order to evaluate whether existing structures that have adequate capacities to resist high seismic loads would also be capable of resisting a blast load with reasonable damage. In addition, typical connections used in construction to resist gravity and lateral loads, as well as connections designed specifically to resist a given blast load were investigated.
The results indicate that the detailing of the connections appears to significantly affect the behaviour of the CLT slab. Typical detailing for platform construction where long screws connect the floor slab to the wall in end grain performed poorly and experienced brittle failure through splitting in the perpendicular to grain direction in the CLT. Bearing type connections generally behaved well and yielding in the fasteners and/or angles brackets meant that a significant portion of the energy was dissipated there reducing the energy imparted on the CLT slab significantly. Hence less displacement and thereby damage was observed in the slab. The study also concluded that using simplified tools such as single-degree-of-freedom (SDOF) models together with current available material models for CLT is not sufficient to adequately describe the behaviour and estimate the damage. More testing and development of models with higher fidelity are required in order to develop robust tools for the design of CLT element subjected to blast loading.
|
10 |
Flexural Strength and Behavior of Timber-Concrete Composite Floors with Hexagonally Headed Self-Tapping Screw Shear ConnectorsArrington, Benjamin David 07 April 2022 (has links)
Timber-concrete composite (TCC) floor systems consist of a bottom layer of wood that is connected to a top layer of concrete using shear connectors. The shear connectors resist slip between the layers, thus allowing wood and concrete develop composite action when subjected to flexure. The objective of this study is to determine the flexural strength and behavior of TCC floor systems that consist of a cross laminated timber wood layer connected to a concrete top layer using hexagonally headed self-tapping screw shear connectors. To accomplish the objective, coupon specimens and full-scale TCC floor panels were tested, and a finite element modelling approach was developed. The coupon tests were used to determine the stiffness of the shear connection and to determine the effect of the screw configuration. The results from the coupon tests indicated that the inclined screw configuration provided the largest shear strength compared to the normal, crossed, and nested screw configurations. Based on the results from the coupon tests, bending and vibration (heel drop) tests were conducted on full-scale panel specimens with an inclined screw configuration and with a strong-axis panel orientation. The results from the full-scale panel tests showed that the flexural stiffness and strength of the TCC floor system was consistent and that the composite floor panels have adequate stiffness to minimize transient floor vibrations that are caused by walking for typical span lengths and typical loading. A finite element model of TCC floor systems was developed to simulate TCC floor systems and calibrated with the test data. The simulated response matched the test response fairly well for partially composite single-span and double-span panels. Additional refinement of the model is needed to better match fully composite panels. The research demonstrated that hexagonal-headed self-tapping screws may be effectively used to connect wood and concrete layers in TCC floor systems.
|
Page generated in 0.0972 seconds