Tryckhållfasthetsutveckling hos broar. En studie av svenska broar byggda under 1900-talet.

En utfackningsvägg är en icke bärande väggkonstruktion, ofta av trä som har för syfte att minimera energiförbrukningen för byggnader i betong. Inuti konstruktionen används ibland stålpelare för att bära ovanliggande konstruktioner. Stålpelarna utsätts för laster som de måste dimensioneras för. Över och under pelarna svetsas plåtar fast för att öka den belastade arean och hindra brott i betongen.I detta examensarbete har därför en datormodell i programmet Excel framtagits. Modellen dimensionerar kantpelare i stål enligt Eurokoderna.

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.

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.

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..

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.

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.

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.

The students are usually eager to develop their mathematical learning. However, the Skolverket can see that this eagerness passes in the early years of school. A study shows that a varied mathematical education creates enthusiasm to learn, which can decrease the negative view of mathematics.The purpose of this study is to see how five pedagogues use laboratory mathematics, their approaches to laboratory mathematics as well as to find out their role in the laboratory education. The result of the study is based on interviews with the pedagogues, who are all teachers for students in year F-3. All of the pedagogues work in a laboratory way, but to different extents.The study shows that the pedagogues aim to make the mathematics as concrete and everyday as possible.

In each classroom there is a teacher with good intentions wanting what´s best for their pupils. But grades and tests in mathematics from 2009 in Sweden shows there is a crack between the subject being taught and the learning child. The purpose with this research is to find an understanding from a teaching and learning perspective of which teaching method is more suitable for teaching and learning mathematics by doing a comparison between two methods. The main question is:What are the advantages and disadvantages of the traditional and the laboratory method of teaching, supported by the two keywords teaching method and learning?This C-paper is based on a qualitative research aiming to gather an in-depth understanding of human behavior.

This is a study made because I would like to see how much money can be saved when reduced soil preparations is used. This is a case study, the farm is located in the north vest part of Skåne, Sweden. I have calculated with four different soilpreparation methods. Alternative 1: Conventional soil preparation, the way the farm is managed today. Alternative 2: Ploughing on depth of 12 centimeters, with a ridge packer followed with sowing. Alternative 3: Eco-tillage Alternative 4: Direct drilling The results of my study showes that Alternative 2 is the most profitable. Alternative 4 is very good if you see to dieselexpenses and hours of work, but the yield is far to low. If the numbers are further analized, it showes that in spring barley the differense between Alternative 2 and Alternative 4 is at a minimum. So if there is lack of time for one reason or another, this might be an alternative in spring barley. The differense in how the farm is managed today and the most profitable alternative in the study, Alternative 2 showes that it can be saved up to 60 940 SEK..

Comfort analyses regarding human induced vibrationsIt is not too common among civil engineers in Sweden to perform comfort analyses considering the vibrations caused by human activities. In addition, the Swedish standards lack requirements to be used for comfort analyses in design of floor-systems. The demand for large spans in combination with slender slabs, is today a reason to investigate the floor-system constructions, in order to prevent disturbing vibrations and oscillations.The purpose of this thesis is to create a guide for how a comfort analysis, considering vibrations, should be implemented. Göran Svedenbjörk who is an expert in structural dynamics has been interviewed where he presents his latest project Värtaterminalen and answers some questions about vibrations due to human activities.Floor-systems, consisting of concrete slabs supported by steel or concrete beams, have been investigated with simulations in the finite element program Abaqus. In the simulations, the influence of various factors on the natural frequency of floor-systems and the acceleration level caused by dynamic loads, is studied.

This research analyzed differences in measurements of magnetic field strength and frequency response in five audio induction loops installed in rooms of wooden construction materials and five audio inductive loops installed in rooms of steel reinforced concrete constructions. The inductive loops were installed at floor level and the measurements were made at the listening height of 1.2m. Measurements of background noise, field strength and frequency response were made at fifteen different measurement points across the room. The research measurements showed that there are differences in field strength and frequency response between these two conditions, whether the audio induction loop is installed in a wooden construction or the audio induction loop is installed in a reinforced concrete construction. The results had a significance level of p=0,05..

The school inspectorate surveys illustrates problems and difficulties for teachers to suit individualized instruction. Therefore, the purpose of the study to investigate whether and in what ways some pedagogues experiences and practice offers the individualized instruction that the governing documents require. The study is based on a qualitative method in the form of semi-structured interviews and observations with four experienced pedagogues. I have been using Piaget's theory of the concrete material's importance for learning and also Vygotsky's theory of the proximal development zone. The results showed that pedagogues understand the importance of individualized instruction.

The school inspectorate surveys illustrates problems and difficulties for teachers to suit individualized instruction. Therefore, the purpose of the study to investigate whether and in what ways some pedagogues experiences and practice offers the individualized instruction that the governing documents require. The study is based on a qualitative method in the form of semi-structured interviews and observations with four experienced pedagogues. I have been using Piaget's theory of the concrete material's importance for learning and also Vygotsky's theory of the proximal development zone. The results showed that pedagogues understand the importance of individualized instruction.