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563 Uppsatser om Pre-placed aggregate concrete - Sida 3 av 38
Värmeförluster vid utvändigt placerade ventilationssystem
To be able to handle tomorrows need for limited energy consumption we need to reduce our use of energy. The building sector stands for around 40 % of all energy consumption in the society. The government has put up a goal to reduce the energy consumption in our buildings with 20 % by year 2020 and 50 % by year 2050 compared with year 1995. To be able to do reach that goal we need a more energy efficient building stock.The main part of the energy used in our buildings is used for space heating. By installing ventilation systems with heat recovery on the exhaust air it is possible to use the heat-energy in the exhaust air to warm up the incoming air.
Vindkraftverk av UHPC 2.2 : En undersökning av högpresterande betong med syntetfiberarmeringen STRUX
Användandet av betong som ersättare för stål vid produktionen av vindkraftverkstorn har ökat den senaste tiden. Betongtorn är betydligt billigare än ståltorn men problem som sprickbildningar, frostsprängningar och följaktligen armeringskorrosion har uppstått bl a på grund av vibrationer från rotorn. I fundamentet i vindkraftverk kan ovan nämnda problem också uppstå och det uppfyller således inte alltid funktionskraven. Det här examensarbetet undersöker möjligheten att eliminera dessa problem genom att använda en sorts högpresterande betong kallad UHPC 2.2 med syntetfiberarmeringen, STRUX. Jämförelser mellan tidigare empiri om högpresterande betong och laborativa tester på UHPC 2.2 visar att den senare är beständigare och ger möjligheter till en större sprickfrihet.
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.
Jämförelse mellan en träbro och en betongbro : En LCA-analys med fokus på koldioxidutsläpp samt en LCC-analys
This report is a thesis for collegeengineering program in structuralengineering at Uppsala University andwas commissioned by the Swedishcontractor Svevia. The study aims toprovide an overview of the mostbeneficial bridge material from bothenvironmental and economic point ofview.The life-cycle analysis covers onlycarbon dioxide emissions, since it isthe most spoken of in today?s climateagenda. Furthermore, this study aims tohighlight which parts, of the systemboundary, that contributes to greatercarbon emissions for the wood- and theconcrete bridge.The life-cycle cost analysis wascalculated with a lifespan of 40 yearsand covers the basic cost of investment,operating and maintenance, anddecommissioning costs.The analyzed constructions in this studyare existing projects that are almostcompleted. Both bridges were designed tohandle loads up to 60 tons.
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..
Grundläggning med cellglas : En studie av byggtid och lönsamhet
This report describes a new foundation method and compares it with a traditional founding of concrete. This new method is called the Koljern technique and uses cellular glass which is called Foamglas. The Foamglas is compounded to founding elements by lightweight steel beams. Foamglas is an insulation material with high compressive strength, and is rot, insect, vermin and acid proof. The cellular glass is also fire proof and watertight, which makes it a very good construction material.The report contains a study of a number of cases for which the Koljern technique is compared with a foundation of concrete.
Hur bemöts Kina i Afrika? : En mångdimensionell idealtypsanalys av Sydafrikas, Zambias och Zimbabwes bemötande av Kinas ökande ekonomiska intresse
The outset of this study is to contribute to the literature concerning China?s increasing economic interest to engage in the African context, its economies and resource abundandce. The overarching research problem is that the approaches held by the respective African state entities may facilitate increasing development gains for the recipient state of this economic interest in principle. To adress this research problem the study is undertaken by conducting a comparative case study where three cases/states, with presumably diverging economic and political status, are likely to effect their overall state approaches differently.Research questions, which are addressed by the creation of an idealtype analytic matrix, concern whether the states of South Africa, Zambia and Zimbabwe take on a more ?permissive? or ?restrictive? approach towards China?s economic interst and whether the approaches can be looked upon on both aggratege and case/area-specific levels.The main findings are that a clear tendency of the ?permissive approach? may be noted on a aggregate level for all cases.
Försök med olika såmaskiner vid konventionell sådd och direktsådd
In this thesis, two studies with different drills were included. In one of the studies two drills were compared: Väderstad Rapid and Väderstad Spirit. In the other study various drills for direct drilling were compared.
The study with Rapid and Spirit was placed in two locations with different autumn tillage; one on ploughed land in Uppsala and one on cultivated land in Västerås, both with relatively high clay content. Rapid drills have a single disc coulter, while the Spirit drills have a double disc coulter. Various aspects were compared such as aggregate distribution, seed placement, emergence, crop yield and economic outcome.
Effects of rubber alley flooring on cow locomotion and welfare
This study investigated the effects of rubber alley flooring on cow locomotion, claw and leg health, production, cleanliness, grooming behaviour and cow exclusion rate in a free stall herd. The study was conducted in a new dairy house with a rotary milking system, with a matched group of cows on traditional scraped concrete alleys used for comparison. All claws were trimmed and lesions recorded at the beginning and end of the 4-month study. Locomotion, claw and leg health, behaviour and hygiene were observed and scored at regular intervals during the study. The results showed that cows on rubber alley floors displayed significantly (p.
Vad ska produkten heta? En kvantitativ studie om produktnamns påverkan på konsumenten.
The number of products offered by retailers has increased immensely during the last two decades, which has resulted in an increase of naming decisions having to be made. The importance of product names has become more significant for retailers offering their products online, as these are more visible to the customer in comparison to products offered offline. Consequently, it is of great value for retailers to gain knowledge about how a product name affects the customers' perception of the product. The purpose of this study is to examine whether product names affect customers perception of the relevant products in the online environment. This has been illustrated by applying the following theories to the relevant product names; meaningful and meaningless brand names as well as concrete and abstract words.
Jämförelsestudie för tre olika metoder att beräkna genomstansning i betong : Skillnader i genomstansningskapacitet för metoderna i BBK04, EK2 och BHB
Before the European construction standards were introduced in January 2011, it was mainly themethod in BBK04 that was used for calculating punching capacity in concrete structures, and in lesscommon cases the method in BHB. The method of BBK04 is easy to use and have had the samestructure since the first was published in 1979. The Concrete handbook method (BHB) where usuallyonly used when a higher punching capacity was needed and the cross-sectional height where fixed,calculations using this method entails more work, but will in return usually give a higher capacity. Italso allows the use of shear reinforcement to increase the cross-section capacity. The method ofcalculating punching shear in EC2 differs largely from the methods of BBK04 and BHB.
Metodik för fastställande av bärförmåga på befintliga betongkonstruktioner
Many buildings are now nearing the end of their service life. This applies to both the older houses from the 40's and 50's to the million project houses that did not prove to be as sustainable in the long run. Often there is a desire to extend the service lifetime, but to do that you need to make detailed inspections. The Folkets hus in Gävle is one of those buildings that is in need of renovation and to fulfill the new requirements that must be met in today's buildings. It is desired to make the buildings rentable space more attractive and to extend the building with two more floors.
Miljöval för byggnadsmaterial : Med häktet i Helsingborg som referensobjekt
Today's climate and environmental issues have now been up for discussion for quite long. Various environmental measures have been taken, but it is not always certain that those measures actually are for the better because of the complexity of our environment. Therefore, studies of whole life cycles are very important even if they are time and resource intensive.Real estate accounts for 15% of global carbon emissions, but also affects our environment in many other aspects. In Sweden this number is even higher. About 30 % of its carbon dioxide emissions originates from building sector and changes are therefore of great importance.
Kartläggning av en fastighets miljöpåverkan : Livscykelanalys av flerfamiljsfastigheten "Teodoliten"
Today's climate and environmental issues have now been up for discussion for quite long. Various environmental measures have been taken, but it is not always certain that those measures actually are for the better because of the complexity of our environment. Therefore, studies of whole life cycles are very important even if they are time and resource intensive.Real estate accounts for 15% of global carbon emissions, but also affects our environment in many other aspects. In Sweden this number is even higher. About 30 % of its carbon dioxide emissions originates from building sector and changes are therefore of great importance.
Kunskapssyn och behov av IKT-verktyg
In a world where digital media is becoming a greater part of people?s everyday and working lives it is plausible to assume that the upcoming generation of pupils expect the teaching media to adapt thereafter. It is this assumption of an increased demand that Natur & Kultur is hoping to be able to meet. This thesis has been a stage in the process of producing digital material in the subject of mathematics for high school students. Specifically the aims of this thesis have been to make a rough description of the largest competitive companies? products within the same market, explore and put together a brief theoretical foundation of contemporary research and produce concrete examples of ideas for digital applications.