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11690 Uppsatser om Filler; comminuted material used in concrete - Sida 6 av 780
Underhållsfria material i broöverbyggnader : Fördelar ur kostnads- och miljösynpunkt vid användning av rostfritt stål och direktgjuten betong
En stor del av Trafikverkets budget går till att reparera och underhålla våra broar. Underhållsåtgärder orsakar också trafikproblem med stora miljöutsläpp och samhällskonsekvenser som följd. Eftersom broar vanligtvis dimensioneras för en lång livslängd på 120 år är det viktigt att planera för långsiktiga lösningar och förutse konsekvenserna av kommande underhållsåtgärder. Genom att använda mer underhållsfria material finns möjligheten att minska kostnaderna och koldioxidsläppen.Målet med examensarbetet är att ta reda på hur stora besparingarna är genom att svara på frågan: ?Vilka fördelar erhålls av att använda mer underhållsfria material i broöverbyggnader ur kostnads- och miljösynpunkt??.
REDOGÖRELSE FÖR SPRICKARMERING FÖR KONSEKVENT DRAGNA BETONGPLATTOR PÅ MARK : Analys av skillnader mellan BBK 04 och Eurokod 2 med tillämpning av svenskt och danskt nationellt annex
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.
"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. .
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.
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.
Datorisering av släktforskarens källor : vad släktforskarföreningar gör och hur de ser på fenomenet
The purpose of this MA thesis is to examine the computerisation of sources that are of interest to genealogists. The primary focus of the thesis is an empirical study, by using a questionnaire addressed to 118 genealogical societies in Sweden, in order to find out what kind of computerisation is being performed by these genealogical societies and what their opinion is of the computerisation of sources of interest to genealogists. The result of this questionnaire has shown, together with printed and electronic material, that there is a good deal of interest from genealogical societies in the computerisation of sources. About half of the genealogical societies who answered the questionnaire are computerising sources themselves and the societies have a positive view in general of the computerisation that is being done and of the increased usage of modern information technology in genealogy. There are on the other hand certain issues that are being discussed such as the important question of the quality of the computerised material.
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.
En IT-baserad plattform för skolförbättring : En kvalitativ studie av lärares informations- och erfarenhetsutbyte
This thesis has created an image of the exchange of information among teachers in the Swedish upper secondary school. The study indicates that the exchange of information seems to be limited at all levels and the exchange that takes place outside the own teaching team occurs mainly through teachers personal networks. The study also shows barriers that may exist and the opportunities that an increased exchange may generate. From the picture that the empirical material provides and the theory that is presented a discussion is made around how IT can best support the organizational learning in schools. A concrete proposal is that at national level an IT platform should be created, which primarily focuses on materials that are created by its users and has an open architecture with a single login..
Införande av mjuka golv för mjölkkor : en fallstudie
Soft rubber flooring have gained in popularity over the last years. Rubber flooring al-lows cow to move more freely without slipping and improves claw and leg health. The purpose of this study was to investigate the influence of a stepwise introduktion of soft flooring on cow`s placement in cow houses with robotic milking.
A case study was carried out in a herd in northern Sweden with 41 cows. Observations were made every 15 minutes between 09.00 and 16.00 concering cow placement in cu-bicles, in cubicle alley, in feeding alley and in feeding alley with the head through feed-ing gate. One observation period was carried out per flooring alternativ: 1) all concrete slatted floor, 2) rubber slatted floor in feeding alley and concrete slatted floor in cubicle alley and 3) rubber slatted floors in feeding alley and solid rubber floors in cubicle alley.
The study showed that 6 %-units fewer cows lay in the cubicles when the feeding alley surface was slatted rubber.
Energi- och kostnadseffektiva klimatskal : För lager-, industri- och kontorsbyggnader
A study to optimize insulation thickness for stock-, industrial- and office-buildings for external walls and roof in an economical perspective has been conducted on behalf of DynaMate. DynaMate?s role is to maintain all Scania?s buildings. Analysis has also included other parts of the building envelope, such as windows, exterior doors and industrial doors. In this thesis, three different types of exterior wall constructions has been investigated, these are a sandwich design consisting of sheet metal and a another one consisting of concrete, as well as a wall of concrete with a coating of plasters.
Dimensionering av betongplatta på lös undergrund. En jämförelse mellan tre beräkningsprogram
Today more effective computer programs are in use, regarding design of geotechnicalconstructions. There is a risk that the theoretical background of the computerprograms, its limitations and the signification of the choice of soil parameter isforgotten when the computer programs become more user-friendly.This Master thesis deals with simulation and analysis regarding three computerprograms, FEM-design, with the addition Raft, Plaxis and BE-slab. Comparisons aremade for settlement and maximum moment in a concrete-plate. FEM-design is a threedimensional FEM-program, foremost created for design engineers. Plaxis is a twodimensional FEM-program, intended for geotechnical engineers while BE-Slab is aBoundary elements program in two dimensions that is mainly used by designengineers.
Inhysningssystem för växande ungtjurar
The purpose of this study was, if possible, to find a housing system for growing bulls that was as optimal as possible for the animal welfare. In order to select housing systems you must take into account the size of the group, body weight and the type of floor. Seven of the international most common housing systems were compared, straw bedding, deep straw bedding, sliding straw bedding, concrete slatted floor, rubber coated slatted floor, cubicles and feeding cubicles. Studies that have examined the proportion of tail, claw and leg injuries and the presence of unnatural behavior in the different systems. In summary, all studies showed that soft underlay were beneficial for the animals in terms of the proportion of bone lesions and swellings.
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.
Eurokoder : en jämförelse mot BKR
In Sweden there are currently two separate guidelines you may use whenperforming calculations on frameworks, BKR and the Eurocodes. Although at theend of 2010 you are not allowed to use BKR any longer and only the Eurocodeswill be viable. The aim of this thesis is to explain how the Eurocodes and EKS work and alsohow they compare to the current guideline BKR. Similarities and differencesbetween these guidelines are also discussed so that the reader will get a betterunderstanding of how the Eurocodes are applied. The areas discussed are asfollows:Principles and adviceSafety ClassesSymbols and IndexesLifespanLoads and partial coefficientThe thesis also deals with the impact that this transition into a new guideline willhave on corporations, guideline costs, education and computer software. As anexample a rough estimate on what costs this transition will create on a companywith 20 employees is also included. Calculations have been performed in order to investigate how the design valuesdiffer between the two guidelines, the Eurocodes and BKR.