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Jämförelse av konstgrässystem med avseende på luftburna partiklar / Comparison of release of airborne particles from different artificial turf systemsNyberg, Roland, Johansson, Oskar January 2018 (has links)
Konstgräs används i stor utsträckning och dess miljöpåverkan är omdebatterad. Oro finns över spridning av mikroplaster och dess miljöpåverkan. Flera studier på spridning av större mikroplast finns, medan spridning av luftburna partiklar är mindre väl utforskat. Studier på detta är till sin natur svåra då tester i fält försvåras av förekomsten av mätbrus i form av partiklar från trafik etc. Detta arbete syftar till att i kontrollerad miljö, genom att använda en Brittisk pendelrigg, undersöka bildandet av luftburna partiklar vid yttre påverkan på konstgräs. Skillnaden mellan olika konstgrässystem studeras, i detta fall olika typer av granulat, s.k. infill. Tester körs med de tre vanligaste granulattyperna, SBR, TPE samt EPDM. I dessa tester kan skillnad påvisas mellan EPDM gentemot de andra två typerna, där EPDM ger upphov till fler luftburna partiklar. / Artificial turf is today widely used, and its environmental impact is much-debated. There are some concerns regarding the spread of microplastics and their environmental impact. Some studies regarding the spread of larger particles exist, while the impact in the form of airborne particles is less well explored. Studies on airborne particulates are quite complicated, as measuring these is made complicated by the already existing particles from traffic and such. In this study a British pendulum is utilized to, in a controlled environment, try to ascertain if a difference may exist between different types of turf. In this study the three most commonly used types of rubber granules, infill, are tested. These are SBR, TPE and EPDM. These tests show a difference in release of airborne particle between EPDM and the other two types, where EPDM generate more airborne particles.
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The Development and Verification of a New Accelerated Polishing MachineKhasawneh, Mohammad Ali 26 August 2008 (has links)
No description available.
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Studded tire wear - comparison between British Pendulum and Pin on disc testing / Dubbdäcksnötning - jämförelse mellan Britisk Pendel ochPinne på skiva provningKozuka, Ryohei January 2017 (has links)
Studded tires are widely used during the winter season in the Nordic countries due to their performance qualities in extreme cold temperatures, however they cause wear on the road surface. This is not only an economic problem but also a health problem due to amount of airborne wear particles that are generated. Therefore, a test method under controlled laboratory conditions for tire and road wear is needed. In this thesis,studded tire wear on concrete road samples are studied using two test equipments; a Pin on disc and a British pendulum rig test. Three different types of concrete road materials and two different types of tire stud geometries were used in the study. The road sample wear ranks the same in both test equipment’s following the rebound hardness of the concrete material. For the two studded tires samples differences in the amount of wear could be noticed. One possible explanation here is the wear dependence on the velocity due to the difference in simulated vehicle speed for the two tests equipment’s. / Dubbdäck används i stor utsträckning under vintersäsongen i Norden på grund av deras prestandaegenskaper i kalla temperaturer. Ett problem med dubbdäck är att de orsakar slitage på vägytan. Detta är inte bara ett ekonomiskt problem utan också ett hälsoproblem då en del av slitaget är partiklar som är luftburna och inandningsbara. Därför finns det ett behov av testmetoder för däck och vägslitage i kontrollerad laboratoriemiljö. I denna studie utvärderas dubbdäcksnötning i två testutrustningar; den brittiska vägpendeln och en pinne-på-skiva maskin. Prov utfördes med tre olika vägvarianter av betong och två olika dubbgeometrier. Storleken på nötningen rankades den samma för de olika vägbeläggningarna i de två olika provutrustningarna. Dock så inverkade dubbgeometrin på resultatet och olika nivåer på vägslitage kunde noteras för de två dubbvarianterna i beroende på val av provutrustning. En möjlig förklaring kan vara ett hastighetsberoende av nötningen då de två olika provutrustningarna simulerar olika fordonshastigheter.
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Investigation of Skid Resistance on Asphalt Pavements in UtahSmith, Aaron B 02 May 2022 (has links)
Friction is one of the essential aspects of pavement performance and safety. Unfortunately, the rate at which the friction data are being collected exceeds the rate at which the data can be proficiently analyzed. Furthermore, the Utah Department of Transportation (UDOT) lacks long-term trend analysis for the many years of locked-wheel skid trailer (LWST) data collected in Utah. In addition, UDOT is missing a statistically adequate correlation equation between friction-testing devices. Likewise, only one method is used in Utah to prequalify aggregates for use in pavements. Finally, there has not been an investigation of the potential use of lithium silicate solution in Utah as a hardening agent to decrease the rate of friction loss. This research consists of five objectives. The first objective was to investigate pavement friction factors that influence skid resistance; methods of measuring skid resistance in the laboratory and the field, including correlations between test results; methods of evaluating aggregate sources; and methods of enhancing skid resistance of asphalt pavements through a comprehensive literature review on these subjects. The second objective was to investigate temporal trends in skid numbers measured using the LWST on Utah highways with different surface treatment types. The third objective was to develop a three-way correlation between the skid number measured with the LWST in the field, the British pendulum number measured with the British pendulum tester (BPT) in the field, and the polish value measured with the BPT in the laboratory. The fourth objective was to investigate selected performance-related properties of aggregates used to produce surface treatments at several field sites representing Utah conditions. The fifth objective was to examine the potential benefits of lithium silicate treatment for improving the resistance of aggregates to polishing. The scope of the research for the five objectives included statistical analysis, field testing, and laboratory experimentation. The findings include, first, a literature review that identified four critical deficiencies in Utah’s friction-related literature, which formed the basis of the remaining four objectives. Second, a statistical analysis of 9 years of LWST data indicated above-average skid values across Utah’s pavement network. Third, correlations were evaluated for multiple friction-testing devices. Fourth, X-ray diffraction testing methods were found to compare favorably to the accelerated polish test. Fifth and finally, the effects of lithium silicate solution on polish-susceptible aggregates were documented. This research has substantially advanced the body of knowledge on pavement friction testing and improving the resistance of aggregates to polishing in Utah through laboratory and field experimentation
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