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2363 Uppsatser om Concrete structure - Sida 8 av 158
Åtkomststudie för robotiserad svetsning av flygmotordetalj
The aim of this thesis was to investigate if the robotized welding method FSW (Friction Stir Welding) could be applied for joining a rotating structure in an aero engine at Volvo Aero Corporation. FSW is expected to introduce less defects than today?s welding methods and could therefore be suitable for critical aero components. The material is the nickel based alloy Inconel 718, however a material experimentation is outside the scope of this report.The main goal of this study is to verify if the ESAB ROSIO robot based FSW-system has a suitable work space to be able to weld the rotating structure, and if the welding tool has accessibility to the joints. The FSW-process needs a rigid fixture, and a number of fix-ture concepts are presented based on a proposed weld sequence.
Stommaterial för villor - trä eller betong?
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.
"Ibland tror jag man kan ha en dubbelmoral inom sig själv..." : - En studie om gymnasielevers förståelse av jämlikhet på en principiell och konkret nivå
The purpose of this study is, by groupinterviewing students in upper secondary school, to investigate students comprehension of equality on a principle level and a concrete level. The questions at issue are as follows; how is the comprehension on respective levels described and is there any difference or similarities between the two levels? Further more, this study also aims to end with a discussion regarding the result from the mainpurpose in relation to the educational environment. In my conclusion there is to be find a certain difference between the comprehensions of equality on the two levels. The conception of equality is in the beginning principled and there is no exception from the worth of every individual but however, when the conception is brought out in reality it gets depended of its context and the comprehension for equality becomes more dynamic. The project will be completed with a discussion regarding the results in relation to the educational environment. .
Manusutveckling av digitala läromedelsapplikationer i matematik : En studie av samtida pedagogisk forskning och utveckling av applikationsmanus för matematikämnet i gymnasieskolan
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.
Hållbarhetscertifiering av stadsdelar : En studie av BREEAM Communities praktiska tillämpning i svensk stadsbyggnad
In this diploma work the approach of determining the required amount of reinforcement in slabs exposed to pure tension is processed, on behalf of Ramböll Uppsala. It is a well-known problem in the industry that there are uncertainties in the determining of the amount of crack reinforcement, especially for structures exposed to pure tension. Cracking caused during the time of dehydration in concrete slabs is the most common defect according to statistics made by CBI[1], which provides numbers as high as 35 % of all the defects caused on slabs are generated by cracks. Comparisons between Sweden's former national standard BBK 04, Building Regulations for Concrete structures due to restrained forces of shrinkage, and the current European standard Eurocode 2 are carried out through theoretical studies and concludes with several examples of calculations. Rigorous calculations of both standards, BBK 04 and Eurocode 2 with application of the national annex in Sweden and Denmark are performed.
Spetsbärförmåga hos betongpålar slagna i friktionsjord
The purpose of this study was to build a database for point-bearing piles in dense noncohesive soil, predominantly moraine. Further, the database was analysed and areas with difficult geotechnical conditions was identified.The database includes for point-bearing piles driven to refusal in moraine. Piles with mainly shaft friction have been excluded. Only concrete piles have been included. Geographically the database covers almost all geotechnical conditions of Sweden.
Programmeringsstruktur med dyslektiskt tänkande
During the period of this project I have programed a web site in php4, and also built the database in MySQL. The purpose with the projekt is to create a common web site for the various activities in the different churches located in the area of Örnsköldsvik. In my project I have chosen to try to find a structure of programming that fits my needs as a dyslexic. In the essay you can find a more thorough description of my procedure and the structure that I have chosen to use..
Evaluation of Capital Structure Arbitrage in the Equity-Credit Markets
Purpose: The purpose of this thesis is to test for the existence of Capital Structure Arbitrage oppertunities in the equity-credit markets. Methodology: The mispricing of Credit Default Swap contracts are calculated and used as input in an Equity-Credit market trading strategy. The returns are then evaluated with a modified Value-at-Risk simulation. Theoretical perspectives: A Merton-based structural model, CreditGrades, is used for credit pricing and a mispricing-convergence trading-strategy between the credit and equity markets is implemented. Empirical foundation: Daily quotes for the Credit Default Swap spread of 37 European firms were collected for a period of two years, as well as equity-prices for the same period and the previous two years, used for model calibration.
Axial- och gradientkrympning hos golv på mark enligt Eurokod 2 : Sprickbredders beroende av betongkvalité, tvångseffekter och armeringshalt
AbstractConcrete foundation slabs are usually exposed to unilateral drying during the curing process. The unilateral drying causes an axial shrinkage and a concave curvature of the construction. The curvature results from the fact that the upper part of the slab is drying and shrinking faster than the lower part. This is called gradient shrinkage.A problem occurs when the slab is considered fully restrained by adjoining structural parts. The deformations caused by axial contraction due to the constant part of the shrinkage and the curvature caused by gradient shrinkage of the slab are then prevented by the fact that the slab is fully restrained.
Tryckhållfasthet för resurssnål betong : Utvärdering i tävling av högsta tryckhållfasthet för resurssnål betong
Betong är vårt vanligaste byggmaterial men cement står globalt sett för 5 % av CO2-emissionerna. Med detta som bakgrund så har CBI Betonginstitutet anordnat en tävling, där målet är att nå den högsta tryckhållfasthet i en resurssnål betong, med enbart 200 kg cement per m3. Syftet med denna rapport är att utvärdera tävlingen, vilket har utförts genom en omfattande litteraturstudie. En första analys av de olika betongrecepten medförde att olika grupperingar kunde urskiljas. Ur dessa fanns det tre stycken vars resultat var väldigt bra. ? Concrete Innovation Centre, som med ett lågt vct, stora mängder granulerad masugnsslagg (81 %) och lite silikastoft (5 %), uppnådde en tryckhållfasthet på 80 MPa vid 28 dygn och 95 MPa vid 56 dygn. ? CBI Stockholm, som genom användandet av ulltrafint filler och silikastoft (4,8 %), uppnådde en tryckhållfasthet på 84 MPa vid 28 dygn och 98 MPa vid 56 dygn. ? Thomas Concrete Group som genom att ersätta cementet med en medelmåttig mängd granulerad masugnsslagg (54 %), liten mängd flygaska (9 %), kalkfiller och silikastoft (5 %), uppnådde en tryckhållfasthet på 94 MPa vid 28 dygn och 98 MPa vid 56 dygn. Det finns således tre recept som vidare studier kan vara rättfärdigade på, de tre ovan nämnda. Det bör tilläggas att en imponerande tryckhållfasthet på nästan 100 MPa, kan uppnås i en betong med enbart 200 kg cement per m3. .
Migration of a very large database with Swedish demographic data, using Microsoft SQL Server
SMC is in the process of developing a micro simulation model. The existing micro simulation model developed at Cornell University for US data, CorSim, is one of the fundamental parts for the new micro simulation at SMC. To develop the Swedish model, Swedish data on all individuals in Sweden during 11 years are also available. These data are organized in a database. This paper describes the process of rebuilding the database to a more useful structure.
Förbättring av U-värde i träkonstruktion för fönster med Aerogel
When constructing a building, a number of aspects must be harmonized in order for it to fulfill requirements ? a building must fulfill requirements such a load-bearing, conservation of energy and a good indoor environment by means of, among other things, moisture proofing .Moisture problems in buildings can affect health negatively. As we are increasingly staying in indoors, demands on a good indoor environment are higher.This work starts with examining moisture problems in slab-on-ground solutions, and then links the various scenarios to moisture problems in a concrete slab of a real building. The building with moisture problems is located in Årby by in Borlänge and moisture damage was found in the slab at an apartment adjoining wall.By reviewing literature written within the field of moisture problem, making hand calculations and modeling in the program Comsol Multiphysics, judgments are made to find explanations as to why the rise of moisture occurred in the building in Årby by.Generally, the following guidelines may be used to reduce the risk of moisture problems in slab-on-ground constructions:Drying of construction moisture before laying the floor material.Using draining layer beneath the slab, to prevent capillary suction.Using insulation under the slab, partly for comfort and to establish the temperature difference between the ground and the concrete slab.Avoid direct contact between the wood and concrete, due to degradation and fouling smells that normally occurs.If necessary, use additional vapor barrier.In addition to the above, there are various methods for moisture-proof and moisture-monitoring by design or by the method ByggaF suited for the entire construction process various events..
Development of concrete compressive strength: a study of Swedish bridges constructed during the 20th century
Tryckhållfasthetsutveckling hos broar. En studie av svenska broar byggda under 1900-talet.
Val av stommaterial : Vilket är det mest fördelaktiga stommaterialet vid uppförande av en hallbyggnad?
When constructing an industrial- or hall building, the most common framework materials thatis used are wood, steel or concrete. Due to an assignment from Byggnadstekniska Byrån ABhas a document been created that makes it possible to investigate how the final costs is af-fected by gapes in between elements and which used foundation. And this with steel as thematerial. The purpose with this essay is to investigate which is the most well fitted materialwhen constructing an industrial- or hall building wood, steel or concrete. Information aboutthe different materials has been collected by litterateurs and by different internet pages.
Omvärldsanpassning inom ideell sektor : en fallstudie om förändring i strukturen av internationella avdelningen på Svenska kyrkan
Over the last few years, many non-governmental organizations (NGOs) in the aid sector have grown and become important economic, social and political actors in Sweden. However this sector has also been hard criticized in terms of aid effectiveness. Church of Sweden (CoS), a well established organization in this sector, has faced new challenges in form of demands from their environment regarding reporting aid work. These demands have pushed the International Department of Church of Sweden into a process for adapting the structure in order to meet the new effectiveness requirements.
Using both, Contingency Theory and Resource Dependence Theory as theoretical framework and a single case study as research strategy, this master thesis goes in deep into the description of the change of the structure of the International Department. This work shows how the different parts of the organization functions and what impact will these changes in the structure mean for the future of the organization.
The analysis of the empirical evidence related to the theoretical framework shows that the organization responds to external demands through a more centralized structure than before.