The goal of this study was to assess the potential of using hardwood lumber in CLT manufacturing. The goal was achieved by addressing four specific objectives. The first objective was to collect CLT manufacturers' perspectives for using hardwood lumber in the current manufacturing setup. The second objective was to determine hardwood sawmills' current ability to produce structural grade lumber (SGHL) from low value logs as a product mix through a survey of hardwood lumber producers in the US. The third objective was to conduct a log yield study of SGHL production from yellow poplar (YP) logs to produce 6'' and 8'' width SGHL to match the PRG 320 requirements. The fourth objective was to determine CLTs' production cost using SGHL and compared it with the CLTs manufactured from southern yellow pine (SYP). The results suggest that all three CLT industries visited and interviewed had sufficient technology to produce hardwood CLTs. The production of hardwood CLTs was mainly limited by the quality and quantity of lumber available. The hardwood sawmill survey results indicated that, currently, less than 10% of the sawmills had all the resources required to produce SGHL. The current ability of the sawmills was measured based on the resources necessary to begin SGHL production. Forty percent of the sawmills would require an investment in sawing technology to saw SGHL, 70% would require employing a certified lumber grader, and 80% would require a planer to surface lumber. Another significant finding was the sawmills' willingness to collaborate with other sawmills and lumber manufacturers. More than 50% of sawmills were open to potential collaboration with other stakeholders if necessary, which is crucial to commercializing SGHL for a new market. The log yield study of yellow poplar helped demonstrate that the mixed grade lumber production method to convert lumber from lower quality zones as SGHL yields higher lumber volume for sawmills and at the same time reduces lower-grade lumber volume. On average, SGHL production increased lumber volume by more than 6% compared to only NHLA grade lumber production when 65% of the lumber was converted to SGHL. The volume of lower lumber grades from 2 common and below decreased from an average of 85% to less than 30% when producing SGHL as a product mix with NHLA grade lumber. This study observed more than 95% of SGHL as Number 3 and better lumber grades. At estimated lumber value, 2x6 and 2x8 SGHL and NHLA grade lumber production as product mix from a log generate higher revenue for all log groups except for the diameter 13" logs. A lower percentage of higher-grade lumber was observed for diameter 13’’ logs than other log groups from this experiment, which resulted in lower revenue. Production cost of CLTs was determined based on the lumber value to manufacture 40' x 10' plain panels with different combinations by lumber grade of yellow poplar and southern yellow pine lumber alone. Production cost was determined by assuming that lumber value contributes 40% of CLTs' total production cost. The 3- ply CLT panels were manufactured using S. Selects lumber in a major direction, and No 1-grade lumber in the minor direction from YP had a production cost of $662.56 per cubic meter, which cost only $643.10 when SYP lumber was used at referenced lumber value. This study concludes that CLT panels from YP cost 3-7 % more than SYP-CLTs at the referenced lumber values. / Ph.D. / This research aims to expand the hardwood lumber consumption in the US by evaluating the opportunity to manufacture cross-laminated timber (CLTs). First, CLT manufacturing industries were visited to know their current capacity to process hardwood lumber. The results suggest that all three CLT industries had sufficient technology to produce hardwood CLTs, and the production was mainly limited by the quality and quantity of lumber available. Commercially hardwood can be used in CLT manufacturing if it can be used for structural application. Hardwood lumber must meet the structural application's minimum requirements to manufacture the structural grade CLTs, so we surveyed the hardwood sawmills to know if they have the required resources to manufacture the structural grade hardwood lumber (SGHL). Only ten percent of the sawmills had required technology to produce SGHL without additional investments. Production of the SGHL also required to generate more revenue for the hardwood sawmills, so we conducted the log yield study to know how the revenue structure of sawmill operation will change from the mixed grade lumber production. At estimated lumber value, 2x6 and 2x8 SGHL and 1-inch National Hardwood Lumber Association (NHLA) grade lumber production as product mix from logs generate higher revenue for all log groups except for the diameter 13" logs. Finally, the production cost of SGHL from the log yield study was evaluated and used to produce CLTs at 40% production cost from lumber at 15% profit margins for sawmills and compare with southern yellow pines CLTs. The results indicate that yellow poplar CLTs cost 3-7 % more than southern yellow pines CLTs at the referenced lumber values. This study concludes that hardwood lumber can be used in CLT manufacturing, so there is an opportunity for hardwood sawmills to expand the market. The first step for commercial production of hardwood CLTs is to produce SGHL on a commercial scale, given that sawmills can benefit from these new products in the current lumber market and meet the minimum requirements of the CLT raw materials.

Det blir idag allt viktigare att tänka hållbart, inte minst inom byggbranschen. Klimatmål, ekonomi och resursförbrukning är en del av de faktorer som bidrar till att branschen måste styras mot ett cirkulärt förhållandesätt. Det finns en potential i de stora mängder flerbostadshus från miljonprogrammet som planeras att byggas om eller rivas. Det saknas dock praktiska lösningar på hur detta görs, det saknas även kunskap samt kompetens inom återbruk. Denna undersökning kommer att utreda hur en ny byggnad kan konstrueras med återbrukad betong kombinerat med KL-trä, genom att analysera strategier för demontering, förband samt ta fram konstruktionslösningar. Studien innehåller en metoddel där beräkningar och programvara beskrivs, en teoridel där strategier för demontering, montering och förband samlats in. Resultatet presenterar de konstruktionslösningar som tagits fram samt resultatet av beräkningar som gjorts, slutsatsen blev att konstruktionen håller med hänsyn till bärighet. I diskussionen skriver författarna om möjliga strategier för återbruk och de metoder och resultat som erhållits. Författarna diskuterar även kring social hållbarhet och cirkulär ekonomi. / Sustainable thinking is becoming increasingly important, not least in the construction industry. Climate targets, economy and resource consumption are factors that contribute to the need to steer the industry towards a circular approach. There is potential in the large number of apartment buildings from the Million Programme that are planned to be rebuilt or demolished. However, there is a lack of practical solutions on how to do this, as well as a lack of knowledge and expertise in reuse. This study will investigate how a new building can be constructed with recycled concrete combined with CLT, by analyzing strategies for dismantling, joints and developing design solutions. The study contains a method where calculations and software are described, a theory where strategies for disassembly, assembly and connections are collected. The result presents the design solutions that have been developed and the results of the calculations made, the conclusion was that the design works with regard to load bearing capacity. In the discussion, the authors write about possible strategies for reuse and the methods and results obtained. The authors also discuss social sustainability and circular economy.

No description available.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第23933号 / 農博第2482号 / 新制||農||1089(附属図書館) / 学位論文||R4||N5368(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 五十田 博, 教授 仲村 匡司, 准教授 倉田 真宏 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

This study was an investigation of Japanese high school teachers' (N=139) beliefs and practices regarding communicative language teaching (CLT). Four research questions were posited concerning the beliefs that Japanese high school teachers hold regarding CLT, how Japanese high school teachers use CLT in the classroom, how Japanese teachers' beliefs and practices differ between academic and vocational high schools, and how the beliefs of Japanese high school teachers, their classroom practices, their learning experience, pre- and in-service training, perceived teaching efficacy, and contextual factors relate to and influence each other regarding the use of CLT. In order to provide answers to these questions, a survey, classroom observations, and interviews were conducted. Before conducting the quantitative analyses, the questionnaire data were analyzed using the Rasch rating-scale model to confirm the validity and reliability of the questionnaire and to transform the raw scores into equal interval measures. Regarding the first and second research questions, the descriptive statistics showed that despite holding positive beliefs about CLT, the respondents to the survey did not frequently use communicative activities. With respect to the third research question, a MANOVA indicated that the types of schools (academic and vocational) did not significantly influence the survey respondents' beliefs and practices regarding CLT. Concerning the fourth research question, the Pearson correlation coefficients showed relatively strong correlations between (a) Classroom Practices and Student-related Communicative Conditions (r = .56) and (b) L2 Self-confidence and CLT Self-efficacy (r = .55). Also, the best fitting path model indicated that (a) Student-related Communicative Conditions impacted Classroom Practices, (b) Positive CLT Beliefs indirectly influenced Classroom Practices via CLT Self-efficacy, and (c) Exam-related Expectations affected most of the indicator variables and Classroom Practices. Related to this, qualitative results indicated that the respondents' learning experience, in-service training, and contextual factors influenced their beliefs and practices. / CITE/Language Arts

The background to the study is the construction industry's global environmental impact. In this study, it is investigated whether CLT (cross laminated timber) and sheep wool insulation is a building technology alternative in an exterior wall based on today’s building standards. To find out if CLT and sheep wool insulation are an alternative for an external wall construction, a literature study and hand calculations were carried out. The literature study summarizes regulations from Boverket BFS 2020:4 regarding moisture, fire, energy and sound requirements. In order to assess how an external wall made of CLT and sheep wool insulation works, three different external wall constructions were developed. Hand calculations were used to determine the heat transfer coefficient and relative vapor of the wall proposals. The results from the calculations show that all wall proposals work with regard to moisture and thermal comfort. Both sheep wool and CLT have a high specific heat capacity, but the volumetric heat capacity and the location of the material determines whether it affects the indoor environment. The study shows that the fire properties of sheep wool mean that the placement of the sheep wool insulation is decisive for whether the wall will be fireproof or not. Calculations of penetration depth in case of fire for CLT show that CLT is a suitable material from a fire point of view. The design flexibility of CLT means that the construction can be adapted so that the sound insulation requirements are met for buildings with special requirements. 54% of the sheep wool produced in Sweden is discarded, according to calculations, the discarded sheep wool can insulate external walls for approx. 11% of the detached houses produced annually. A study was conducted on whether wool can cause allergies, the information does not indicate that sheep wool insulation can cause allergies. The study concludes that combining sheep wool insulation with CLT is possible however the use of CLT is more justified in a multi-storey house than a single-family house. / Bakgrunden till studien är byggbranschens globala miljöpåverkan. I den här studien utreds det om KL-trä (korslimmat trä) och fårullsisolering är ett byggnadstekniskt alternativ i en yttervägg utifrån dagens byggnadsstandard. För att ta reda på om KL-trä och fårullsisolering är ett alternativ för en ytterväggskonstruktion genomfördes en litteraturstudie och handberäkningar. Litteraturstudien sammanfattar föreskrifter från Boverkets byggregler BFS 2020:4 gällande fukt-, brand-, energi- och ljudkrav. För att bedöma hur en yttervägg uppbyggd av KL-trä och fårullsisolering fungerar togs tre olika ytterväggskonstruktioner fram. Med handberäkningar bestämdes väggförslagens värmegenomgångskoefficient och relativa ånghalt. Resultatet från beräkningarna visar att samtliga väggförslag fungerar med avseende på fukt och termisk komfort. Både fårull och KL-trä har hög specifik värmekapacitet men materialets volymetriska värmekapacitet och placering avgör om den påverkar inomhusmiljön. Studien visar att fårullens brandegenskaper gör att placeringen av fårullsisoleringen är avgörande för om väggen blir brandsäker eller inte. Beräkningar av inträngningsdjup vid brand för KL-trä visar att KL-trä är ett lämpligt material ur brandsynpunkt. Designflexibliteten hos KL-trä gör att konstruktionen kan anpassas så att ljudisoleringskraven uppnås för byggnader med särskilda krav. 54% av den i Sverige producerade fårullen kasseras, enligt beräkningar kan den kasserade fårullen isolera ytterväggar i ca. 11% av småhusen som produceras årligen. Det gjordes en undersökning om ull kan framkalla allergi, informationen tyder inte på att fårullsisolering kan orsaka allergi.  Studien kommer fram till att kombinera fårullsisolering med KL-trä är möjligt och att användande av KL-trä är mer motiverat i ett flervåningshus än ett småhus.

The most important part of learning a language is being able to communicate, understanding others and making yourself understood. Communicative Language Teaching (CLT) is a perspective on language teaching where the focus is on the students and letting them communicate and interact with each other in the learning language. CLT creates safe classroom environments and great knowledge in how to use the language in everyday life. The aim with the study was to investigate English teachers’ usage of CLT and attitudes towards using CLT in the Swedish classroom during English teaching. Seven English teachers in Sweden participated in the study by answering questions in a semi-structured interview that was designed to answer the study´s research questions. The main results show that although English teachers are not familiar with the concept of CLT, they still have a positive attitude towards many tools and activities that are in keeping with it – and they also use these tools and activities. Hence, to get the most out of what CLT has to offer in the Swedish classroom, support from schools in the form of a teacher-training program would be appropriate.

This project seeks to propose an ideal model for housing in a future where it is no longer feasible at a lower density. It identifies several characteristics of good housing, primarily: individual response to site, desirability, and sustainability, then applies them in the design of an apartment building on a specific site. The project also touches on questions of what makes a living space desirable, namely the preservation of the tenant's individuality and the fostering of community, each of which is examined and applied through the architecture. The project stresses that individuality is supported through a tenant's choice of living space and, therefore, that buildings following this model should not be identical copies, but rather unique responses to their own sites following the guiding principles of this project. It addition, as a secondary objective, the project explores the intricacies of mass timber construction and building code. / Master of Architecture / As the population rises and it becomes clearer that we can no longer afford to gobble up land for low density housing, our idea of what housing should be must also grow. It's inescapable that the future of housing involves refocusing on medium density apartments so that we can house more people on less land, but making that happen would involve a paradigm shift in what we consider the ideal housing condition. Convincing people to stay in apartment buildings instead of moving into a single-family house requires buildings that respond to their individual site, provide desirable apartments, respect the environment, and preserve the sense of community that is often found in low density developments. This project seeks to propose a model for the future of housing.

Increasing awareness of sustainable building materials has led to interest in enhancing the structural performance of engineered wood products. Wood is a sustainable, renewable material, and the increasing use of wood in construction contributes to its sustainability. Multi-layer wooden panels are one type of engineered wood product used in construction. There are various techniques to assemble multi-layer wooden panels into prefabricated, load-bearing construction elements. Assembly techniques considered in the earliest stages of this research work were laminating, nailing, stapling, screwing, stress laminating, doweling, dovetailing, and wood welding. Cross-laminated timber (CLT) was found to offer some advantages over these other techniques. It is cost-effective, not patented, offers freedom of choice regarding the visibility of surfaces, provides the possibility of using different timber quality in the same panel at different points of its thickness, and is the most well-established assembly technique currently used in the industrial market. Building upon that foundational work, the operational capabilities of CLT were further evaluated by creating panels with different layer orientations. The mechanical properties of CLT panels constructed with layers angled in an alternative configuration produced on a modified industrial CLT production line were evaluated. Timber lamellae were adhesively bonded in a single-step press procedure to form CLT panels. Transverse layers were laid at a 45° angle instead of the conventional 90° angle with respect to the longitudinal layers’ 0° angle. Tests were carried out on 40 five-layered CLT panels, each with either a ±45° or a 90° configuration. Half of these panels were evaluated under bending: out-of-plane loading was applied in the principal orientation of the panels via four-point bending. The other twenty were evaluated under compression: an in-plane uniaxial compressive loading was applied in the principal orientation of the panels. Quasi-static loading conditions were used for both in- and out-of-plane testing to determine the extent to which the load-bearing capacity of such panels could be enhanced under the current load case. Modified CLT showed higher stiffness, strength, and fifth-percentile characteristics, values that indicate the load-bearing capacity of these panels as a construction material. Failure modes under in- and out-of-plane loading for each panel type were also assessed. Data from out-of-plane loading were further analysed. A non-contact full-field measurement and analysis technique based on digital image correlation (DIC) was utilised for analysis at global and local scales. DIC evaluation of 100 CLT layers showed that a considerable part of the stiffness of conventional CLT is reduced by the shear resistance of its transverse layers. The presence of heterogeneous features, such as knots, has the desirable effect of reducing the propagation of shear fraction along the layers. These results call into question the current grading criteria in the CLT standard. It is suggested that the lower timber grading limit be adjusted for increased value-yield. The overall experimental results suggest the use of CLT panels with a ±45°-layered configuration for construction. They also motivate the use of alternatively angled layered panels for more construction design freedom, especially in areas that demand shear resistance. In addition, the design possibility that such 45°-configured CLT can carry a given load while using less material than conventional CLT suggests the potential to use such panels in a wider range of structural applications. The results of test production revealed that 45°-configured CLT can be industrially produced without using more material than is required for construction of conventional 90°-configured panels. Based on these results, CLT should be further explored as a suitable product for use in more wooden-panel construction. / <p>External cooperation: Martinson Group AB and Research Institutes of Sweden (RISE)</p>

ANNOTATION On the banks of the Střední Novomlýnská reservoir, in the cadastre of the municipality of Strachotín, the diploma thesis presents the overall design of a multifunctional complex, based on a sensitive connection between organic farming, well-breeding, and eco-tourism. The proposal shows the concept of farming in a "closed circle", with regard to the environment. The urban solution deals with the selected land with an area of 20 ha. The architectural part closely introduces the system of objects, creating a new landscape, perceived by both a human and bird's eye perspective. The layout solution analyzes in detail the functional arrangement of the farm, trying to meet all the requirements for efficient management while maintaining the organic regime and the coexistence of visitors and employees. The complex also offers a restaurant, multifunctional hall, conference rooms, classrooms, workshops, a gym, and exhibition areas. Accommodation is provided by a system of separate buildings, presenting the current possibilities of natural construction and environmentally friendly technologies to the guests, while maintaining the comfort of living. The farm is fully equipped for weddings or corporate events. The design and material solution use a maximum of natural materials in combination with current technologies. In addition to designing a viable multifunctional unit, the aim of the thesis is also to bring added value to the region, by holding annual cultural events and regular activities for children and seniors from the surrounding municipalities. At the same time, the work aims to create a sensitive counterpoint to current tourist destinations in the area.