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557 Uppsatser om Asphalt concrete - Sida 1 av 38

Grön asfalt och NCC : rätt tillväxtstrategi för en asfaltproducent?

NCC ROADS Sweden east is a part of the NCC Corporation. The company mainly produces aggregates, asphalt and concrete. They have taken the environmental issues seriously and been working with that since the middle of the nineties. When manufacturing asphalt large a quantity of fossil energy is needed. The company is now about to make further progresses by manufacturing environmental friendly asphalt (?green asphalt?) with using bio-energy.

ALTERNATIVA ASFALTSBELÄGGNINGAR : Möjligheten att använda icke petroleumbaserade bindemedel

This report investigates the possibility to use non-petroleum based adhesive (biobitumen) in asphalt. The main reasons for replacing bitumen are the fact that oil prices are rising, the threat of peak oil and the fact that the asphalt industry is becoming more environmentally friendly.The main purpose of this report is to investigate whether there are any non-petroleum based adhesives on the market. If so, how can they be used? The questions covered are:? Are there any other alternative asphalt coatings available?? Can bio-oils be used in asphalt?? If the bio-oils can be used, what are the details their properties?? How does a cold climate affect the bio binders?? What is the Swedish asphalt industry?s opinion about bio asphalt?The project was concluded through literature studies, consultations with people in the asphalt industry and through several interviews.The conclusion of this report is that there are some existing non-petroleum based adhesives on the market. They are mainly used for bike paths, sidewalks and parkareas.

Planering & produktionsstyrning : Lean filosofin vid produktion av asfalt

Lean is a production philosophy which is about increased resource use while meeting customer requirements. The foundation of lean comes from Toyota and their production philosophy The Toyota Way. Professor Jeffrey k. Liker has worked with Toyota's production philosophy and Lean for a long time and has created a 4 P model and 14 principles that characterize the Toyota production system (TPS), which many sources refer to.The aim of my work is to study the working procedure of asphalt projects from sales to the laid asphalt with a focus on planning and production management. The goal is to examine how the lean philosophy can be applied in planning and production to simplify the flow of asphalt projects based on Likers model and principles.

Identifiering av lakbara potentiellt farliga ämnen i gummiasfalt

The main purpose of the project was to identify potential environmentally harmful substances which can be leached from rubber asphalt. A method for analysing asphalt was developed and three rubber asphalt materials were analysed after being cryogrinded. One of the materials was also tested in a road machine made for testing of asphalt paving. The particles created in the machine were analysed in the same manner as the cryogrinded asphalt materials.The asphalt materials were leached by water during 24 hours. The leachates were extracted with dichloromethane, dried with sodium sulphate and concentrated to a small volume.

Självkompakterande betong vid platsgjutning av anläggningskonstruktioner

By using modern methods of casting concrete, cast in place can get more effective and industrialized. A modern method is self compacting concrete. By using this type of concrete, advantages like improved working environment and rationalized construction can be reached. Because the concrete doesn?t need to be vibrated, the amount of staff on site and the noise can be reduced.

Effektivisering av asfalttransporter : Enhetligt arbetssätt för styrning och tidsskrivning av asfalttransporter

The cost of transportation has strongly increased in the recent years, transportations which are a major part for the construction companies. Skanska Asphalt which is a part of Skanska Sverige AB has noticed that there are significant cost savings to be made with the purchasing of transports. The transports in this case is about asphalt, where the costs are about 10% of the outsourcing business turnover. The purpose of this thesis is to study the working practice that Skanska Asphalt are using today in controlling and time-writing, for the asphalt transportations. Resulting in recommendations on how to improve the working practice at Skanska Asphalt.This study was conducted with the help of a number of interviews with Skanska?s employees and with suppliers of transportation to describe the practices which are being used in during the asphalt transportation.

Dimensionering av vägens bärlager : Hur påverkar asfaltbetongblandningen och hur effektiv är svensk dimensioneringsmetod?

Det här arbetet handlar om asfaltbetongblandningar och hur variationen av dessa vid projektering påverkar vägarnas dimensionering i överbyggnaden mer specifikt bärlagret. Arbetet är baserat på litteraturstudier av den senaste teorin kring dimensionering av asfaltbetongblandningar i väglager samt tillhörande kravskrifter både från svenska och amerikanska myndigheter. Den inledande delen i examensarbetet omfattar bakgrunden till vägdimensionering. Inledningsvis behandlas materialet asfaltbetong och derss egenskaper för att sedan gå vidare till allmänt om vägar, hur de utformas, vägens funktionella egenskaper och skador som kan uppstå. Detta ska ge läsaren tillräckligt med bakgrund för att följa med i resten av arbetet där man kan läsa mer ingående om deformationsskador och vilka parametrar som är till stor vikt när man studerar skador som uppstår i asfaltbetongen samt relationen till dem egenskaper bitumen har. Rapporten avslutas med att resonera kring eventuella problem kring dimensioneringsmetoder samt betydelsen av blandningens hållfasthetsegenskaper och hur de påverkar vägarnas tjocklek. Slutsatsen i rapporten är att asfaltbetongblandningen har en betydelse för dimensionering av bärlager och att det kan vara någonting att beakta oftare vid vägdimensionering speciellt vid blandningar som skiljer sig mycket från standardvarianterna..

Inverkan av tvång i gjutfogar och i betongkonstruktioner på
elastiskt underlag: Influence of Restraint in Casting Joints
and in Concrete Structures on Resilient Foundation

In this report, the risk of cracking in joints and/in adjacent concrete is estimated by checking shear forces in joints and the ratio between the actual maximum principal stress ant the actual strength of the concrete. The shear force has been estimated both by simple methods as well as by two-dimensional calculations. The risk of cracking in the concrete and/or in the joints is estimated with the computer program ConStre. The restraint from a resilient foundation or rock on a young concrete construction is estimated by a simple method that is exemplified. It is shown that the restraint can be neglected in some cases.

Icke-linjära modelleringsteknikerav förspänd betongkonstruktion : Reaktorinneslutningen på Forsmark 3

A new material model, for the FE-program ADINA, has been verified against twoexperiments. One unreinforced concrete beam and one reinforced concrete beam.The model, DF-concrete, has the possibility to estimate true concrete. However theresults indicate that in order to be sure that the estimations are true, there ought tobe data from the true concrete to verify against.Two FE-models have simulated the behavior of a ring-shaped part of the nuclearcontainment vessel. The results from the first, frictionless, model agree with similarsimulations and hand calculations for high pressures in the containment vessel. Thesimulations of the nuclear containment vessel show cracking in the concrete after10-11 bars of over pressurization.

Asfaltdjungeln: En ANT-analys av en svensk kartell

In the year of 2001 the largest known cartel in Swedish history wasexposed to the public and brought to justice. Eight years later, afterseveral trials, the so-called Asphalt Cartel was finally found guilty bythe Swedish Market Court for having been cooperating illegally anddistorting prices.The overall purpose of this paper is to study how the cartel wasmanaged in order to be sustained over time. By applying actornetworktheory I examine what kind of heterogeneous materials thatwere combined for purpose of creating the cartel and how in practicethey were held together.In order to understand how the cartel was sustained I also include ananalysis on why it suddenly fell apart in 2001. However, my studyshows that through the years the cartel repeatedly experiencedcrisis, and therefore constantly fell apart and was recreated throughprocesses of negotiation..

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..

Miljövärdering av resurssnål betong med införande i BIM

This thesis aims to illustrate how environmental impact can be reduced, through the use of lean concrete. It also illustrates how environmental data can be applied to a house through implementation with BIM. In this study a unique concrete structure developed by Swedish Cement and Concrete Research Institute is assessed for environmental impact, by calculating the carbon dioxide equivalents using LCA methodology. The construction is a sandwich element where the concrete is made ??up of three layers.

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.

Betong - Förvånansvärt lättflytande!

Concrete is a very common construction material. It´s characteristics are strength, durability and formablility. Superplasticizer is a common admixture, which changes the properties of concrete. Today (spring 2007) there are no certian mathematical methods to calculate the required percentage of this admixture needed to give the necessary set slump flow in the overall concrete recipe. Concrete batching companies must therefor experiment with different amount of superplasticizer in order to meet the specified slump and strength. The purpose og this report is to investigate if any mathematical relation can be established between the amount of superplasticizer used and the slump flow achieved. After carrying out some practical experiments using four different superplasticizers a direct relationship can be establish between the percentage of admixture used and the slump/flowability achieved. Unfortunatly at present due to the numerous variables, the calculation of mathematical formula can not be achieved..

Utmattning av vägbroar i armerad betong enligt eurokoder

Since 1 January 2010 it is a requirement to use the European standards, Eurocodes, in Sweden when constructing bridges. One chapter that has caused an extra amount of problems for the engineers is the one about fatigue analysis, which resulted in us doing this thesis.To do this we had to read all of the Eurocodes that direct, or indirect deals with fatigue and calculating of such. We have read the background documents for the Eurocodes and master?s thesis in the subject. We also studied the calculations of bridges constructed by different construction firms.We have chosen to limit the thesis to discuss only road bridges made of concrete due to the lack of method for verification of concrete in the national appendix.

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