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The Global ETD Search service is a free service for researchers
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 1 to 4 of 4 (0.03 seconds)Spelling suggestions: "subject:"lerlager""
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Dränerande bärlagermaterial : Produktion och egenskaper av bärlagermaterial i bergtäkterna Kjula och EkerKarldorff, Harri January 2016 (has links)
I detta examensarbete framtogs två bärlagermaterial med hög dränerande förmåga från NCCs bergtäkt i Kjula samt standardprodukt 0/32 mm som användes som referens. De sökta egenskaperna som beaktades var hög permeabilitet, hög porositet, god bärighet och kostnadseffektiv produktion. Tester gjordes på materialens porositet, permeabilitet, vattenkvot och materialens kornstorleksfördelning analyserades. Materialet framtogs genom att avskilja 0/16 i ingående till kross och sedan sikta fram sortering 0/32 mm. Materialet analyserades i laboratorium där korndensitet och kornstorleksfördelning bestämdes. Vattenkvoten fastställdes genom torkning i ugn och permeabiliteten mättes med rörpermeameter. Resultaten visade att den viktigaste parametern för ett materials permeabilitet är andelen finmaterial (<0.063 mm) och genom förändring av ingående material till kross kan permeabiliteten och porositeten förändras i utgående materialet. Mätning av materialens egenskaper visade att permeabiliteten förbättrades till k = 4.4 * 10-3 m/s jämfört med referensmaterialet k = 1.8 * 10-4 m/s. Materialets porositet n ökade från n = 32.58 %, för referensmaterialet, till n = 37.96 %.
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Dimensionering av vägens bärlager : Hur påverkar asfaltbetongblandningen och hur effektiv är svensk dimensioneringsmetod? / Road pavement design : What is the effect of the asphalt concrete mixture and how effective are Swedish design methods?Helmersson, Elin, Nestéus, Tim January 2013 (has links)
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. / This essay is about bitumen concrete pavement mixtures and how the variation of these affects the design of the superstructure of the road during the design-stadium, more specifically the pavement. The essay is based upon studies of literature written about the latest theory of asphalt concrete design for roads as well as the texts with regulations from Swedish and American government agencies. The introductory parts of the essay consist of the background to road design. Initially bitumen concrete and its characteristics are discussed and move on to general information about roads, how they are designed, the roads serviceable characteristics and finally the damage that can develop. This is meant to give the reader enough background to follow the rest of the essay where you can read more about deformation and which parameters that are of importance when you study deformation in bitumen concrete as well as the relation between the characteristics of bitumen concrete and bitumen. The essay is then finished with a argumentation about eventual problems with design methods and the significance of the bitumen concrete mixture’s strength parameters and how they affect the thickness of the road superstructure. The conclusion is that the asphalt concrete mixture has an impact on the design of the pavement of the road and that it should be something to take into account more often in road design, especially when you are using a mixture that differs much from the standard mixtures.
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Framställning av dränerande bärlager från bergtäktAbu Sulaiman, Iyad, Ibrahim, Miran January 2023 (has links)
Bearing layers are used in road and building constructions as underlying soil layers to provide stability and support to the top layer that takes up the load. A normal bearing layer contains different amounts of materials such as stone, gravel, and filler. That mixture of materials contains a large amount of filler to give the product tightness and stability. Draining bearing layers usually contain less filler than ordinary bearing layers, because their purpose is to improve the drainage properties and reduce the risk of damage due to water collection.This thesis work took place at NCC's quarries in Sälgsjö and Hammarby. At NCC's rock quarry, there already is a standard bearing layer with a grain size of 0/32 and a filler content of approximately 4–5%. In this degree project, a production process has been created to obtain a drain bearing layer where the filler content is reduced to approximately 2–3%. The requirement for a draining carrier layer is 2–3% filler content and this requirement has been followed in this production process. The draining bearing layer has been produced based on a standard product with the same grain size.There are practical limitations in how the operations work and what capabilities are required. Moisture in the material has also been a limitation. In this project, work is done with freshly crushed material, which has a relatively low moisture content (1–2%). A vibration-free screen like the function of the harp has been designed and built. Then the standard product was run through the harp at different gradients and the new product was analyzed in the lab to see what filler content was achieved. A simulation test was performed using a FEM design program called Digiroad at Chalmers University of Technology in Gothenburg.The results demonstrate that the utilization of the developed models of harp screens reduces the proportion of filler in the material. Additionally, the conducted harp screen analyses confirm that the designed harp screens are effective in transforming a standard bearing layer into a draining bearing layer, which helps to prevent water accumulation under roads or buildings and thus reduces the risk of damage and problems. The efficient production process for producing draining bearing layers can be of great importance to ensure a sustainable and safe infrastructure.
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Samband mellan geologiska och bergmekaniska egenskaper i bergmaterial som bärlager till riksväg 51 : Riksväg 51 sträckan Svennevad - KvarntorpskorsetLandeman, Philip January 2018 (has links)
This thesis was created to ensure the quality of the rock which would be crushed to base layer construction material, in a road cut at Swedish highway 51, and to find a possible link between the rock's abrasion resistance and its mineralogy. Rock samples were collected, and among other things, several ball mill tests were carried out. The design of the road project was carried out by Loxia Group AB with NCC Group as contractor.A total of 18 rock samples and 2 base layer samples were taken in the area and they were all tested in a ball mill. The results showed that of the 18 rock samples, 2 samples had a ball mill value of less than 16 on the scale, 10 samples had values from 16 to 20, in addition to this, 3 samples had values from 20 to 21 and 3 samples had values in excess of 21 on the Swedish ball mill scale.Of the 3 samples with a ball mill value higher than 21, all contained a larger amount of biotite. Biotite did not appear to the same extent among the samples that ended up further down the ball mill scale. This link was so clear that a conclusion was subsequently drawn from this. The samples taken on the prefabricated base layer both had a ball mill value between 16 and 20. Overall, both the base layer and the rock material passed the Swedish Government’s Transport Administration’s requirements according to "TRVKB 10, Obundna lager". The rock type that was on the south part of the rock cut, adjacent to a deformation zone, had way too poor quality to undergo a ball mill test and therefore there are no values taken from that area.The conclusion of the work is that the rock material overall meets the Swedish Government’s Transport Administration’s requirements for base layer construction materials according to "TRVKB 10 Obundna lager", that a clear link between the proportion of biotite in a rock material and its abrasion resistance exists, and that the broken rock in the south should not be used as construction materials since the rock has insufficient mechanic capacity.
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