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 %.

Esteves et.al. 2020 visade att syrgasdelignifiering ökar den totala fiberladdningen men leder inte alltid till ökad pappersstyrka. Denna studie syftar till att undersöka hur fiberladdning påverkar massans egenskaper.  För att testa hypotesen att ökningen av dragstyrkan beror på den större mängd sekundärt finmaterial som orsakas av malningen, testades vissa egenskaper hos massan, såsom vattenabsorption, med och utan malning avmassan. Två kraftmassor med olika initialt kappatal, 91 respektive 52, syrgasdelignifierades med olika alkalilsats under varierad tid. De massor som hade den lägsta och högsta mängden totala fiberladdningar maldes med PFI-kvarn. Water Retention Value (WRV), Schopper-Riegler (SR), Fiber Saturation Point (FSP) och finmaterial analyserades. WRV testades också efter att finmaterialet avlägsnats från massan.  Resultaten tyder på att massan med en större ökning av den totala fiberladdningen jämfört med den kraftkokta massan vid ett givet kappantal kan resultera i en högre ökning av FSP och WRV. Massor med större ökning av den totala fiberladdningen bildade mer finmaterial vid malning, vilket resulterar i en högre ökning av SR. / According to a previous study from Esteves et. al. 2020, it was found that oxygen delignification can increase the total fiber charge but does not always increase the paper strength. This study aims to investigate how fiber charge has an impact on pulp properties.  To test the hypothesis that the increase in mechanical strength for the fiber is due to the bigger increase of secondary fines caused by the refining process, some properties of the pulp such as water holding capacity were tested with different treatments: refining and no refining. Two kraft cooked pulp with different initial kappa numbers of 91 and 52 were subjected to oxygen delignification with different alkali charges and reaction times. When the characterization tests such as, kappa number and total fiber charge measurement have been determined, the samples which had the lowest and the highest total fiber charge were PFI refined and other analysis such as, water retention value (WRV), Schopper-Riegler degree (SR), fiber saturation point (FSP), and fine content, were done. WRV was also tested without fines.  The results suggest that the pulp with a higher increase in total fiber charge when compared to the kraft cooked pulp at a given kappa number can result in a higher increase in FSP and WRV. A higher increase in total fiber charge can also have a high tendency to create fines, due to the higher swelling ability, resulting in a higher increase in SR.

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.