I Sverige idag finns ett statligt vägnät som finansieras och underhålls av de Svenska myndigheterna genom Trafikverket. På Trafikverkets avdelning för underhåll planeras och genomförs underhållsåtgärder för att vägarnas standard ska uppfylla de beslutande kraven som finns. En av de dimensionerande faktorerna vid underhåll av asfaltsvägar är spårdjup, spårdjupen får inte överstiga den specifika underhållsstandarden som finns eftersom om det sker ökar olycksrisken och en försämrad framkomlighet kan uppstå. Ett av syftena med detta examensarbete är att undersöka om det går att förutse var och varför asfaltsbeläggningar inte uppfyller underhållsstandarden som finns. Metoden som används grundar sig i en analys av mätdata som inhämtats genom laserskanning av vägytan med hjälp av en mätbil. Datan presenteras i form av grafer och figurer i Trafikverkets öppna webbportal PMSV3, graferna och figurerna har analyserats för att sedan utgöra resultatet och slutsatserna i arbetet. Resultatet som framgick stämmer som helhet överens med grundinställningen innan arbetet påbörjades, att det går att se en indikation efter några år vart beläggningen kommer att överstiga maximalt spårdjup enligt underhållsstandarden. Men att förutse om och var beläggningen kommer försämras först och mest är svårare i ett tidigt skede. Arbetets slutsatser har bidragit till att flera förslag på fortsatta arbeten har föreslagits, vilket får arbetet att anses lyckat. / In Sweden today, there is a state road network that is financed and maintained by the Swedish authorities through the Swedish Transport Administration. At the Swedish Transport Administration maintenance department, maintenance measures are planned and implemented to ensure that the standards of the roads meet the decision requirements that exist. One of the dimension factors for maintenance of asphalt roads is rut depth, the groove depth must not exceed the specific maintenance standard that exists because, if this happens, the accident risk increases One of the purposes of this thesis is to investigate whether it is possible to predict where and why asphalt pavements do not meet the maintenance standard that exists. The result which appeared to be in agreement with the basic attitude before the work was started, that it is possible to see an indication after a few years where the occupancy will exceed the maintenance standard But to predict if and where the asphalt coating will deteriorate first and most is more difficult at an early stage The work's conclusions have contributed to several ideas for further work being proposed, which makes the work to be considered successful

abstract: Highway safety is a major priority for the public and for transportation agencies. Pavement distresses directly affect ride quality, and indirectly contribute to driver distraction, vehicle operation, and accidents. In this study, analysis was performed on highways in the states of Arizona, North Carolina and Maryland for years between 2013 and 2015 in order to investigate the relationship between accident rate and pavement roughness and rutting. Two main types of data were collected: crash data from the accident records and roughness and rut depth data from the pavement management system database in each state. Crash rates were calculated using the U.S. Department of Transportation method, which is the number of accidents per vehicle per mile per year multiplied by 100,000,000. The variations of crash rate with both International Roughness Index (IRI) and rut depth were investigated. Linear regression analysis was performed to study the correlation between parameters. The analysis showed positive correlations between road roughness and rut depth in all cases irrespective of crash severity level. The crash rate data points were high for IRI values above 250-300 inches/mile in several cases. Crash road segments represent 37-48 percent of the total length of the network using 1-mile segments. Roughness and rut depth values for crash and non-crash segments were close to each other, suggesting that roughness and rutting are not the only factors affecting number of crashes but possibly in combination with other factors such as traffic volume, human factors, etc. In summary, it can be concluded that both roughness and rut depth affect crash rate and highway maintenance authorities should maintain good pavement condition in order to reduce crash occurrences. / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2017

This research has investigated the effect of tyre rutting of wheeled construction plant performance traversing in wet and deformable terrain, specifically clay and sand. The purpose was to translate the wheel rutting into performance reduction measured in drawbar-pull. The ultimate goal was to translate the power loss into practical effects on cost, time and other economic variations on construction projects that are characterised by movement of wheeled plant on long haulage deformable roads. In order to achieve this aim, mathematical modelling was deployed based on Newton’s laws of motion, principles of energy conservation and numerical integration. The model is based on a single rigid wheel because construction plant tyres are inflated to high pressure in order to support heavy loads thereby translating the flexible tyres into rigid mode. The results from the mathematical model were verified using a three stage robust verification process which included computational analysis based on two existing semi-empirical methods and real experimental data. Laboratory experiments using Mobility SF- 3713 were also used to check the validity of the results. The results from the mathematical model verify that a flexible tyre can operate in rigid mode if it encounters softer and wet ground. Results further indicate that the soil cohesion, angle of shearing resistance and moisture content play key roles in the subsequent power loss created by motion resistance. All the results from computational analysis and the experiments were found to be consistent with the mathematical model results. The study concludes that there is ample evidence to suggest that there is significant power loss associated with wheeled construction plant traversing in soft terrain which can be assessed. The study further concludes that a combination of economic decisions on variables must be considered with respect to existing ground conditions. This will considerably reduce uncertainty levels in cost and resource management on construction projects.

Disertacijos tikslas – parengti magistralinių automobilių kelių asfaltbetoninės dangos eksploatacinių rodiklių prognozės matematinius modelius, atsižvelgiant į tampriosios dangos konstrukcijos savybes ir transporto priemonių (TP) eismo intensyvumą (EI). Darbe iškelti šie svarbiausieji uždaviniai: išanalizuoti automobilių kelių asfaltbetoninės (AB) dangos eksploatacinius rodiklius lemiančius svarbiausius veiksnius ir atskleisti šių rodiklių blogėjimo priežastis; atlikti magistralinių kelių dangos konstrukcijų (KDK) sluoksniams naudojamų medžiagų kokybės rodiklių tyrimus; nustatyti AB dangos komponentinės sudėties, fizinių bei mechaninių rodiklių ir AB mišiniams naudojamų medžiagų kokybės rodiklių sietį; ištirti AB dangos lygumo ir provėžų gylio kitėjimo dėsningumus; nustatyti AB dangos, kitų (KDK) sluoksnių medžiagų kokybės rodiklių sietį; parinkti dvi racionalias magistralinių kelių tampriosios dangos konstrukcijas (skirtingam TP eismui). Disertaciją sudaro įvadas, keturi skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir priedai. Įvade aptarta tiriamoji problema, darbo aktualumas, tyrimų objektas, darbo tikslas ir uždaviniai, tyrimų metodika, darbo mokslinis naujumas, darbo rezultatų praktinė vertė ir ginamieji teiginiai. Pirmajame skyriuje išnagrinėti įvairių šalių mokslininkų atlikti automobilių kelių asfaltinės dangos bei jos konstrukcijos eksploatacinių rodiklių ir jų funkcionavimo trukmės tyrimai. Antrajame... [toliau žr. visą tekstą] / The aim of the dissertation is based on the properties of flexible road pavement structures to develop a mathematical models for predicting the performance of wearing courses used in the pavements of the main roads. The main tasks of the dissertation are as follows: to analyze the main factors influencing the service indices of asphalt concrete pavements and to determine their reasons; to investigate the quality of materials and mixtures used in pavement structural layers of the main roads; to determine the interaction between asphalt concrete pavement composition and the quality indices of mixture materials; to study regularities of the change in pavement roughness and rut depth; to determine the interaction between the quality indices of materials used in pavement structural layers; to select two rational flexible pavement structures for the main roads (for the different traffic volume). The dissertation consists of introduction, four chapters, general conclusions, the list of references and the list of author’s publications on the topic of the dissertation, addenda. Introduction describes the studied problem, topicality of the problem, the object of research, also the aim and tasks, research methodology, scientific novelty, practical value of the results and the defended propositions. Chapter 1 gives the analysis of scientific researches made by different countries in the field of the performance of asphalt concrete pavements and their structures, duration of their... [to full text]

The aim of the dissertation is based on the properties of flexible road pavement structures to develop a mathematical models for predicting the performance of wearing courses used in the pavements of the main roads. The main tasks of the dissertation are as follows: to analyze the main factors influencing the service indices of asphalt concrete pavements and to determine their reasons; to investigate the quality of materials and mixtures used in pavement structural layers of the main roads; to determine the interaction between asphalt concrete pavement composition and the quality indices of mixture materials; to study regularities of the change in pavement roughness and rut depth; to determine the interaction between the quality indices of materials used in pavement structural layers; to select two rational flexible pavement structures for the main roads (for the different traffic volume). The dissertation consists of introduction, four chapters, general conclusions, the list of references and the list of author’s publications on the topic of the dissertation, addenda. Introduction describes the studied problem, topicality of the problem, the object of research, also the aim and tasks, research methodology, scientific novelty, practical value of the results and the defended propositions. Chapter 1 gives the analysis of scientific researches made by different countries in the field of the performance of asphalt concrete pavements and their structures, duration of their... [to full text] / Disertacijos tikslas – parengti magistralinių automobilių kelių asfaltbetoninės dangos eksploatacinių rodiklių prognozės matematinius modelius, atsižvelgiant į tampriosios dangos konstrukcijos savybes ir transporto priemonių (TP) eismo intensyvumą (EI). Darbe iškelti šie svarbiausieji uždaviniai: išanalizuoti automobilių kelių asfaltbetoninės (AB) dangos eksploatacinius rodiklius lemiančius svarbiausius veiksnius ir atskleisti šių rodiklių blogėjimo priežastis; atlikti magistralinių kelių dangos konstrukcijų (KDK) sluoksniams naudojamų medžiagų kokybės rodiklių tyrimus; nustatyti AB dangos komponentinės sudėties, fizinių bei mechaninių rodiklių ir AB mišiniams naudojamų medžiagų kokybės rodiklių sietį; ištirti AB dangos lygumo ir provėžų gylio kitėjimo dėsningumus; nustatyti AB dangos, kitų (KDK) sluoksnių medžiagų kokybės rodiklių sietį; parinkti dvi racionalias magistralinių kelių tampriosios dangos konstrukcijas (skirtingam TP eismui). Disertaciją sudaro įvadas, keturi skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir priedai. Įvade aptarta tiriamoji problema, darbo aktualumas, tyrimų objektas, darbo tikslas ir uždaviniai, tyrimų metodika, darbo mokslinis naujumas, darbo rezultatų praktinė vertė ir ginamieji teiginiai. Pirmajame skyriuje išnagrinėti įvairių šalių mokslininkų atlikti automobilių kelių asfaltinės dangos bei jos konstrukcijos eksploatacinių rodiklių ir jų funkcionavimo trukmės tyrimai. Antrajame... [toliau žr. visą tekstą]