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5243 Uppsatser om High-strength concrete - Sida 2 av 350

Utvärdering av den bärande tegel- och betongstommen i en byggnad från år 1916

This Master thesis is about a postal- and telegraphic building in Eskilstuna, Sweden. The construction methods for the specific building and buildings in general from the same time are described. The purpose of the report is to describe the loads acting on the building and how it has been built and why it has been rebuilt during the years. After this, possibilities of reconstruction and adaptation for today?s demands can be evaluated.

Användning av högpresterande betong i husbyggnader : Materialförsök och modellering

Idag är intresset för högpresterande betong (HPB) växande runt om världen då fördelarna är många, eftersom slankare, tätare, starkare och lättare konstruktioner kan tillverkas. Detta examensarbete handlar om materialförsök och modellering för en typ av HPB som ska användas i husbyggnation. Arbetet inleddes med materialförsök i färskt tillstånd, där god gjutbarhet och konsistens eftersträvades. Utgångspunkten var från ett grundrecept med två olika ballastsorter (slaggballast med flygaska och krossballast från asfaltindustrin med silikastoft), vilka namngavs till pilotförsök 1 och pilotförsök 2. Vidare valdes pilotförsök 1 att provas i hårdnat tillstånd då det visades att det var mer ekonomiskt lönsam eftersom ballasten inte behövde siktas, lägre vct tillhandhölls och att flygaskan som användes i pilotförsök 1 är billigare än silikastoft som användes i pilotförsök 2. Resultaten efter 28 dygn för de materialförsök som utfördes i hårdnat tillstånd var:Tryckhållfasthet; 141,9 MPaDraghållfasthet; 7,0 MPaBöjdraghållfasthet; 10,0 MPaElasticitetsmodul; 46,4 GPaKrympning efter 56 dygn; 0,5 ?Samtliga försök utfördes enligt svenska standarder (SS). Dessutom vidareutvecklas och förbättrades ett redan arkitektoniskt gestaltat Attefallshus ur ett konstruktions- och hållbarhets perspektiv, där fokus låg på transport- och produktionsförutsättningar.

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.

Eurocodes : Beräkningsjämförelser mellan eurocodes och BKR

In the year 2010 a transition will take place here in Sweden from the present rules how to dimension buildings in to the common rules with have been developed in Europe, the Eurocodes. Eurocode is the term for a collection standard that contains calculation rules in how to dimension constructions and buildings. They are developed by the European standardize committee.The purpose with this examination work is to get an insight of what changes this will contribute to, and how it will affect the dimensioning. Are there going to be any differences in the dimension you finally chose?To investigate these possible differences two constructions will be calculated first in the present Swedish rules, and then in the coming eurocodes.One of these two constructions will be build completely in steel, while the other will be build completely in concrete.

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.

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.

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.

Övergång till helkrossballast : En studie för Strängbetongfabrikerna i Veddige och Herrljunga

This exam report has been developed in association with Strangbetong AB, Sweden.The natural gravel that is being used as fine aggregate for concrete production today is an ending natural recourse and the Swedish government has decided to strongly reduce the extraction from the year of 2020. The only reasonable replacement is aggregates from crushed rocks but this material has other properties than natural aggregates. The concrete manufacturers now have to learn how to use these new fine aggregates in a cost effective way in order to ensure the quality of their concrete production.In this project, crushed aggregates and combination of crushed and natural aggregates have been tested with existing formulas for fresh concrete. The two parameters yield stress and plastic viscosity have been measured which gives a good description of the workability of the fresh concrete. Different methods to make measurements on the dry fine aggregates, has also been tested, to find out if there is any correlations between these parameters and the parameters from the measurement on the fresh concrete..

MUSKULÄR STYRKA VID MULTIPLA REPETITIONER: : SKILLNADER VID STYRKETEST I BÄNKPRESS OCH LIGGANDE BÄNKRODD MED SKIVSTÄNGER AV OLIKA DIAMETEROMFÅNG

Introduction: A complex interaction between muscles, tendons, bones, joints and nerves are required for optimal function of the human hand. It is known that an individual?s grip strength is vital for performance of physical demanding tasks such as strength training with free weights. Strength training including a thicker grip around the bar may enhance the strength of the grip in the athlete without other special routines for grip strength development. The purpose of this investigation was to examine the difference in performance in multiple repetitions in two strength training exercises using two different sizes on the bar, to look for correlations between grip strength of the subjects hand and the amount of repetitions executed with two different size of the bar and finally the correlation of hand size and the amount of repetitions executed with two different size of the bar.Method: 15 strength training men (23,9 ± 4,1 years), underwent measurements of hand size, maximum grip strength, 1 repetition maximum (1RM), a 80 % of 1RM weight strength test with two different  bar sizes.Results: The results from the present investigation indicates a 21,1 % reduction of 80 % of 1 RM weight performance in repetitions executed in the bench press with the thicker diameter of the bar and a 66,2 % reduction in repetitions executed with a 80 % of 1 RM weight in the lying bench row with the thicker diameter of the bar.

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.

Smarta prefabmoduler för småhus i betong

This report examines the possibility of developing a modular system for concrete homes that cancontribute to greater diversity of today's market. The issue was whether it ? from a competitive pointof view ? is possible to produce smart prefab modules that customers themselves can combine to avilla. The report addresses the question how the modules and wall panels should be designed for thegreatest variety of floor plans.With regard to what is asked of the customer interviews where held for the purpose ofunderstanding concrete's popularity and elements of high value in their homes today. The answersfrom the interviews laid ground for four prototype homes which were made to demonstrate how theelements can be combined to achieve different types of houses..

Telias 4G i Umeå

This report presents the results of the tests of data rate and signal strength that I have conducted. The tests have been performed in the municipality of Arvidsjaur, Sweden. The report also contains the conclusions I have drawn from the results as well as an introduction to radio and the technology used in the nets that have been testedThe equipment used is:LG G2 cellphone used to test Telias 3GHuawei b593s-22 3G/4G router used to test Tele2s 3G/4GMobile Broadband Gateway R-90 used to test Net1s CDMAThe data rate has been tested with bredbandskollen (www.bredbandskollen.se). The signal strength(RSSI) has been read in the configuration menu of the broadband routers as well as in the cellphone.The conclussions drawn:Net1s net appears to be more used compared to its capacity than the other netsTele2s net has a high and even data rate where it?s signal strength is sufficient.

Dimensionering av betongkonstruktioner : En jämförande studie av BBK 04 och Eurokod 2 vid dimensionering av balkar och pelare

Today, we use BKR and BBK 04 when designing concrete structures inSweden, which will, in the near future, be replaced by Eurocode 2. When you are designing buildings, you will use Eurocode 2 Part 1-1 and with this new standard, some new rules and general rules will be necessary to adopt. To examine how BKR and BBK 04 tells apart from Eurocode 2 when designing concrete structures, one beam and one column with often common dimensions, is studied. The beam is designed with consideration of (considerate to) durability at bending moments, shear forces and control of cracking. The column is designed with consideration of durability at eccentric axial load and bending moments in cross section on account of (due to) geometric imperfections. BBK 04 has gone one step closer to Eurocode 2 than earlier editions and the things that are different, when calculating reinforcement, is how they use the partial factors.

Cirkelträning - en kombination av styrka och kondition

In Sweden the amount of people with obesity has increased with almost 50 % during the past 20 years and is now including 500 000 people. A larger energy intake than energy consumption is today one of the most important cause of overweight and obesity that exist in the world. This requires more knowledge about healthier eating habits combined with moderate intensive exercise, exercise that is simple, effective and amusing. A god solution is a combination of fitness training and strength training, a type of circuit training. It is distinguished by a high intensive work in short periods and with a short break.

OMBYGGNAD AV TRAFIKPLATS : Ekhagsmotet i Jönköping

We have the tradition in Sweden to build villas and houses with a wooden framework. It has become natural for us because we have so much forest in our country. Building with wood has advantages, it is easy to process, but also disadvantages, as it is sensitive to moisture.Finland has long made use of the thermal blocks to build villas. It is a type of bricks that are a bit like a sandwich element, with a core of EPS and concrete on both sides of the core material. The concrete is hollow, so that after the walls has been bricked up you pour concrete into the hollow bricks.The issue of this report is to find out if concrete can be an alternative to wood as framework material in villas.

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