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551 Uppsatser om Hemp concrete - Sida 2 av 37

Alternativa stråbränslen i växtföljden :

The purpose of this report is to find out which crops, that are good for strawfuel, and can be grown i the area around the city of Lund. The background of this report it that Lunds energy is planning to bild a biofuelheated thermal power station in Örtofta outside of Lund. I have in the report limited me to the crops hemp, whole crop (triticale), reed canary grass, elephant grass and jerusalem artichoke. I have through a documentary research checked the crops, cultivabillity in the south of Sweden, and how they should fit, in the Scanian crop sequence. Hemp is an annual crop which probably could manage in the Scanian crop sequence. Whole crop often triticale because of it´s high yield and low rate of shed seed. Could also fit into the crop sequence of crop in Scanian. Triticale is annual, and could be grown at the same kind of fields as used to wheat, whith is why it would be possible to grow it in Scania. Reed canary grass is a reedlike grass that is easy grown at most soils.

Behuggning av betongytor: ett test av hantverksmetoder

During the latter half of the 18th century, when concrete started seeing general use in modern cities, the use of different methods to give the concrete a finished surface texture saw use. One of these was using different methods of mechanically altering the surface using a slew of cutting and crushing techniques with mallet and chisel. This was done in order to hide the often dull and gray look of concrete, and allude to other more expensive and luxurious stones. The work would possibly have been done by experienced stonemasons, using much of the same techniques and tools they would have used while working natural stones. Or did they? This essay explores, through the use of traditional handcrafts and tools, the claim that the working of concrete surfaces can be done with the same tools and skillset as the working of natural stone.

EN TOTALKOSTNADSJÄMFÖRELSE MELLAN CELL-, SKUM- OCH LECA-BETONG

This report provides a comparison between the products cellular concrete, foam concrete and LECA concrete. The questions to be answered during the work is how the cellular concrete stands up in cost terms to the existing competitors on the market, how the concrete products differ in design work, and in which situations the concrete varieties are preferred to use.Cellular concrete is a variant of ordinary concrete, with the difference that the ballast is exchanged from stone materials to expanded polystyrene beads (EPS). This substitution gives a product with higher insulation values but lower weight than ordinary concrete.The work was carried out by designing a survey which was sent to two hundred randomly chosen companies across Sweden, to see the building industry?s opinion of the product cellular concrete. The survey showed that cellular concrete was equals its competitors in terms of price, while the product was said to be more flexible, quicker and easier to cast.Then some of the companies, who participated in the survey, were interviewed to see more carefully, how the price, the workmanship and the time for casting and dehydration differed between the products.

Betong - Förvånansvärt lättflytande!

Concrete is a very common construction material. It´s characteristics are strength, durability and formablility. Superplasticizer is a common admixture, which changes the properties of concrete. Today (spring 2007) there are no certian mathematical methods to calculate the required percentage of this admixture needed to give the necessary set slump flow in the overall concrete recipe. Concrete batching companies must therefor experiment with different amount of superplasticizer in order to meet the specified slump and strength. The purpose og this report is to investigate if any mathematical relation can be established between the amount of superplasticizer used and the slump flow achieved. After carrying out some practical experiments using four different superplasticizers a direct relationship can be establish between the percentage of admixture used and the slump/flowability achieved. Unfortunatly at present due to the numerous variables, the calculation of mathematical formula can not be achieved..

Utmattning av vägbroar i armerad betong enligt eurokoder

Since 1 January 2010 it is a requirement to use the European standards, Eurocodes, in Sweden when constructing bridges. One chapter that has caused an extra amount of problems for the engineers is the one about fatigue analysis, which resulted in us doing this thesis.To do this we had to read all of the Eurocodes that direct, or indirect deals with fatigue and calculating of such. We have read the background documents for the Eurocodes and master?s thesis in the subject. We also studied the calculations of bridges constructed by different construction firms.We have chosen to limit the thesis to discuss only road bridges made of concrete due to the lack of method for verification of concrete in the national appendix.

Hisskärna av skalväggar i höga byggnader : Ett alternativ till den platsgjutna kärnan

A common way to stabilize high rise buildings is to use an elevator core built of concrete. Today, we use to build these elevator cores of in-situ concrete. Precast concrete twin wall (double wall) is a semi-finished product that has become more common in recent years. This diploma work studies how the twin wall works out as structural elements in an elevator core. The work also shows some possible ways of designing twin walls and highlights some important parts of the design that will be vital to the stability of the building.    The result shows that it is important to think through where the element joints should be placed.

Prefabricerade stödmurar i betong :

This is a booklet with information and inspiration about precast retaining walls. The three chapters contain information about concrete as a material, how the surface of the wall can be altered, and a chapter with ideas for a new precast wall. I have obtained information through books, interviews, lectures and fairs. The retaining walls on the market do not correspond to the requirements of the Landscape Architects I have interviewed. I have therefore considered their opinions in the chapter containing my new ideas for new retaining walls.

Lek och lärande : En studie av vad lärare och elever associerar ett laborativt arbetssätt i matematik med

During recent years, the trend of Swedish students? negative performance and results in mathematics has been discussed. It is agreed that a change in teaching methods is necessary in order to solve this issue. Thus we found it interesting to take a closer look at an alternative way of teaching. The purpose of this study was to find out what teachers and students associate concrete mathematics with and make a comparison between them.

Försöksmetod för automatisering av kvalitetssäkring av SKB

Within all industries, there is a change in working time required; this also includes the construction sector. However, the way construction sectors are differentiated is by not having been given the opportunity to be practiced or tested.  The aim of this thesis that we have done in collaboration with the Concrete Industry was to investigate the possibility of developing an automated method for quality assurance of SKB at the site. The idea is to make the O-funnel to be more utilized and therefore ensuring that the appropriate concrete quality is provided which eventually would lead to a better development in the production process.The project has involved theoretical work and laboratory experiments. The theoretical work gave us a good foundation at the beginning of the project. After gathering the information and material, the laboratory experiments began by SCC in their laboratory in Hammarby. The collected data from the various laboratory tests formed the foundation for trying to relate measurements for consistency of SCC with each other and therefore find out how measurements from O-funnel varies with different concrete mixtures.

Stenmjöl eller naturgrus i betong : En jämförande studie

 The objective of this thesis is to examine the difference in workability in fresh concrete, when crushed fine aggregate replaces natural gravel. The shape of the fine aggregate,  packing and flow of six crushed material and three natural materials will be determined by easy studies, the results will be compared with a slump cone test..

Datormodellering av en värmelagrande betongväggs inverkan på det termiska klimatet i ett växthus

This report describes the building of a computer model that makes it possible to simulate the thermal climate in a greenhouse. The computer model is built on the physical theory of heat exchange that occur in a greenhouse, such as radiation and convective heat exchange. The model also includes the heat storage that is active in a greenhouse.The computer model is used to simulate the thermal climate in a greenhouse under three periods, winter, spring and summer. It also investigates which effect a concrete wall has on the thermal climate in a greenhouse. The purpose of putting a concrete wall in the greenhouse model is to investigate the possibility to store heat during the day and then use this heat when the temperature drops during the night.The result from the simulations shows that a concrete wall levels the big difference in temperature that normally occurs under a day in a greenhouse.

Samverkan mellan nya cementtyper och tillsatsmedel för betongtillverkning

Cement manufacture accounts for 3-5 percent of total global carbon emissions. There is a growing interest in reducing the environmental impact and conserve limited natural resources. In cement production, clinker productions consume 87.5 percent of the total energy consumed in the cement manufacture.Cementa has since many years, focused on reducing the environmental impact of cement production. The work has involved the entire production process from selection of alternative fuels to the development of cement with less clinker content. During 2013/2014, two new types of cement (Bascement and CEM II / B) will be introduced to the Swedish market.

Användbarheten av Tekla i Betongkonstruktioner : En jämförelsestudie mellan två modelleringsprogram

This thesis has examined the Tekla Structures modeling software and answered the question of whether it could act as a suitable modeling program for the design department at Bjerking AB in Uppsala. The method used in this work is a case study of a previous project with existing basis to work form. The demarcation of the study was to examine only the usability of the foundations of in situ concrete. The work examined three main areas within the design process. The first was to model the concrete elements then to model the reinforcing and ultimately production of the drawings. Because Autodesk Revit was the existing modeling program in the Department conducted the evaluation as a comparison between the two programs.

Ekonomisk utvärdering av betonggjutformar

This report will try to evaluate the use of rented concrete casting moulds, which are used to build walls and system of joists. The evaluation is only examining the economical aspects.The cost of using concrete casting moulds is a big part of the total production expenses. Therefore it is important that the calculated price not exceeds the final costs of the casting moulds. The calculated price is the price used in the process of making an offer.The evaluation consists of a comparison of the calculated price and the final costs for three building projects. It also evaluates the exploitation of the concrete casting moulds for each project.The report is made by Sven Gynne and Anders Alexandersson at School of Engineering, Jonkoping University, in cooperation with PEAB Jonkoping.

Stålfiberarmerad betong för platta på mark : -En kostnads- och sprickbreddsanalys

AbstractToday there is an opportunity to reinforce concrete with steel fiber reinforcement. In some cases, completely replace the conventional reinforcement. Replacing conventional mesh reinforcement with steel fiber reinforcement in slabs on ground has shown economic benefits, less crack width and less reinforcement amount.Today there are no Swedish standard for designing steel fiber reinforced concrete, what is there is different international recommendations.In this work, design methods for steel fiber concrete are used according to RILEM and Bekaer Swedish AB's software DRAPRO. For other design methods Eurokod 2 is followed.In this work, the design of slabs on ground that are not exposed by large tension strength been designed. Design of crack-reinforcement and restrictions of crack width have been conducted in three different slabs on ground.The calculations have been performed using only conventional reinforcement and only steel fiber reinforcement, and the results are then compared.The results of the theoretical analysis are summarized in tables that compare the amount of reinforcement, crack width and economic cost.This work showed that the slabs on the ground reinforced with steel fibers provide less crack width with a minor amount of reinforcement.

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