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864 Uppsatser om Cross- laminated timber - Sida 1 av 58
Cross-Laminated Timber? En fallstudie av Hyttkammaren samt en jämförelse med prefabricerat betongelement ur platsomkostnadsperspektiv
Approximately ten people die every year at building sites in Sweden. Every year TheWork Environment Authority (Arbetsmiljöverket) receives 3200 accident reportsfrom the construction sector. The Swedish building contractor Skanska has the vision:?Zero accidents?. Only at Skanska Sweden, where this diploma work is preformed,350-520 accidents and mishaps are reported every year for the last 5 years.
Tillämpning av nya beräkningsmetoder för branddimensionering av träkonstruktioner - analyser och jämförelser
To build high-rise buildings made of timber has for long been limited by national laws, due to the lack of knowledge in engineering solutions. Frame structures made of wood has for a long time been associated with major fire hazards and consequently lower safety and this connection is still being made today. The increased environmental awareness in recent years has contributed to the exploitation of indigenous building materials, including wood from our own Swedish forests and has become increasingly common. Increased knowledge about how structures behave in fire and how they can be protected in order to achieve safe timber structures has resulted in a growing interest in these structures in the construction industry. Research in the area is constantly updated and new laws allow any number of storeys in wooden buildings in Sweden as long as the performance requirements are fulfilled.The main part of this work has involved calculations of the fire resistance and load bearing capacity of floor and wall constructions.
KL-trä och limträ : hur råvarans kvalité tas tillvara i den färdiga produkten
Detta är en studie som behandlar hur väl kvalitén i trädet tas tillvara för sortimenten limträ och KL-trä. Limträ består av ett antal lameller som limmas samman med fibrerna i längdriktningen medan KL-trä är en krysslimmad skiva som består av en mängd sammansatta lameller. Trä är ett heterogent material som har skilda egenskaper beroende på var och hur det växt. Genom att sätta samman heterogena trälameller vill man skapa en homogenare produkt. Eftersom att produkterna används inom olika områden kan man tänka sig att det går att optimera användandet av råvaran till respektive produkt.
Limnologen : Inblick i svenskt träbyggande
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..
Kostnadsutvecklingen inom flottningen i Dalälven 1900-1970
The paper, with a brief summary of timber floating in Sweden and also of some previous re-search in this field, contains a study on costs for timber-floating in the river Dalälven located in central Sweden. The public used timber-floating system in Dalälven and the historical background about this activity is described. The study is focused on the total costs for timber-floating in the public open floating system in Dalälven from 1900 to 1970, the year before the timber-floating was definitively closed down. Also the costs for separating the logs of a specific owner when they reached the point where they could be separated from the timber of other owners are analyzed..
Enkätundersökning hos markägare inom SCA Skog Jämtlands förvaltning
This report is a joint venture with SCA Skog AB in the Jämtland forest management area. The company is a major player in the timber market in northern Sweden, and also a large business globally with offices in over 100 countries. The purpose of the study was to find out how timber suppliers want feedback/follow-up after completion of timber business. To determine this, a questionnaire survey was sent out to 75 landowners who supplied the wood for the company during the past year. The questionnaire consisted of a total of 15 questions with the opportunity to comment on certain issues.
Utveckling av golvlucka för hoppgropssystem i kommunal idrottshall
In this thesis a concept for floor hatches for foam pits has been developed. Since there is an existing solution that is powered by hydraulics and is expensive, the goal was to develop a cheaper solution, as simple as possible.A number of different concepts were developed and evaluated. A concept with five sections that are pulled to the side and stacked on each other was chosen as it was thought to have the lowest risk of crush injuries and to be easiest to manage and control. In the opening behind the foam mattress a lifting table is placed to regulate the height of the stacked sections.To be allowed to be installed in the floor of sports halls the sections must be dimensioned according to the construction standards for these types of buildings. Different dimensions of beams in steel and wood materials were evaluated and of those, who lived up to the requirements of the standard, a concept was chosen.
Markägares val av skogspartner :
Derome Skog AB is a purchase company whose main task is to provide Derome Timber's sawmills in Halland with timber raw material. Because of the very hard competition in the roundwood market it is important to know what kind of purchase offers are required in order to buy a valuable product from forest owners.This study aims to elucidate the crucial factors when private forest owners choose to harvest and sell their forest. As base for this study, a questionnaire has been performed with private forest owners. The result of the study shows that it is not particularly often that the timber price is the crucial factor why the forest owners choose to harvest and sell the forest products; i.e. timber, pulpwood as well as energy assortments.
Kvalitetssäkring vid arbete med fukt i virke
There are many factors in a building project that has to collaborate with one another in order to reach the desired end result, how you work with moisture issues in timber is a very important one. While constructing Varbergs Hospital, the building company Skanska came in contact with the issue of extra high demands on the moisture content in timber. What they requested from us was a moisture program in which you clearly could follow the routines regarding work with moisture in timber. The aim is to use this program as a help during the work, in order to achieve a good result.We have developed this study in addition to the moisture program. The aim is that this study will give you a deeper understanding of the important factors to consider.
Uttag av kvalitetsvirke a björk - potential och problem
The purpose of this report is to illustrate potentials and problems with withdrawal of quality timber of birch. The purpose is also to describe possible ways to increase available quantities of quality timber. Former research is reviewed as introduction. The study begins with a prognosis of future volumes of birch timber based on consequence analyze by Swedish Forestry Agency. To illustrate the importance of active maintenance, two stands are estimated and simulated in the Heureka module StandWise.
Förändrad aptering av massaved från 3- till 4-meterslängder vid gallring inom Södra : en systemanalys av effekter från avverkning till levererad virkesråvara
The costs of logging and of transportation with truck are dominating the total cost of wood delivered at industry. To support the profitability for the members' forestry the processing and handling with the timber has to be as efficient as possible. Increased length of pulpwood in thinning is one conduct that can result in higher productivity and/or lower costs. The study is scaled as a system analysis with the aim to exemplify the differences between working with 3- and 4-meter as standard length of pulpwood, related to biological aspects, timber receipts, cost of logging and cost of transportation with truck. Important aspects are if the change is technically and biologically feasible and economically profitable.
Husväggar av massivträ: En kostnadsjämförelse
Trä är och har sedan länge varit en av Sveriges mest exporterade råvaror. Branschen sysselsätter idag omkring 100 000 människor i landet. I samband med de senaste årens miljödiskussioner bör husens uppbyggnad diskuteras. Syftet med detta examensarbete är att främja husbyggnation i massivträ som de senaste åren fått mer publicitet inte bara på den svenska marknaden men också i centraleuropeiska länder.Frågorna i detta arbete handlar om att identifiera de vanligast förekommande ytterväggskonstruktionerna och jämföra deras materialkostnader samt kostnader för arbete vid montering. För att ha kunnat göra en rättvis jämförelse har BBR?s energikrav varit den gemensamma nämnaren för ytterväggskonstruktionerna.Frågorna har besvarats genom intervjuer med tillverkare av prefabricerade massivträväggar, träregelväggar och betongväggar varpå energiberäkningar utförts i samband med framtagning av olika väggkonstruktioner för att få fram tre lika energieffektiva väggar.
Metod för urval av bäriga bestånd längs med bäriga vägar i Sveaskogs planeringsområde Råneå och Överkalix :
With increased need for flexibility in timber deliveries, forest roads become an important factor. The disintegration of roads during the spring season can be avoided if it is possible to rule cutting areas to stands with good carrying capacity along roads with good carrying capacity.
The goal with this work was to create a method to find the stands with high carrying capacity located near roads with high carrying capacity, and select them into a collection file. The method was based on Esri ArcGIS 9 and the tables that follow within that program.
The method resulted in four different themes:
1. Collections with GYL 100 that cross the bufferzon for 0, 1, 2 and 3 class roads. Result 36 collections.
2. Collections with GYL 100 and 200 that cross the bufferzon for 0, 1, 2 and 3 class roads.
Fiberföstärkning av Limträbalkar
Glulam is a product that was engineered to make use of timber in a more efficient way. Bychoosing timber of similar quality and discarding natural defects during production, thedevelopment of a stronger cross-section is achieved.Carbon fiber is a relatively new material with a high tension capacity. This feature is used toexamine how the bending capacity of the beams improve by adhering carbon fiber laminateson the lower edge of the beamsThe strength of the material is tested with three experiments: carbon fiber on the bottom of thebeam (a), carbon fiber attached to the lower sides of the beam (b) and carbon fiber in thebeam, covered with a layer of wood (c)The results show that the first case, where the carbon fiber is attached to the bottom of thebeam, gave the best result with an increase in capacity of 59 % compared to the nonreinforcedcontrol. The other two cases also show an improvement in capacity, beam-type 3had a capacity increase of 47% and beam-type 4 increased with 25 %Tests were also made with glulam beams reinforced with fiberglass, but these tests were notanalyzed in depth because the purpose was to compare the capacity to carbon fiber. Thisbeam improved its capacity by 40.3%.The tests show that carbon fiber as a reinforcement material for glulam is a good choice whenthere is a requirement for stronger cross-sections in both new production and renovation ofold buildings.
Effekt av gödsling och gallring på mö?belvirke av furu
This thesis is about the effects of fertilizing and thinning on furniture timber from redwood. Interviews of furniture manufactures have been made and observing of timber from the Swedish fertilizing and thinning trails. The result from the interviews showed which properties that is important for the furniture manufactures and then the result from the observation showed which type of management of the forest that gave the most timber that had those properties. .