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There are many variables that affect the viscoelastic properties of asphalt mixtures with time, among which age hardening may be considered one of the important ones. Age hardening of asphalt mixtures is an irreversible process, which contributes to a reduction of the durability of pavements and eventually increases the maintenance cost. Beside the environmental effects, ageing in asphalt mixture depends on the physicochemical properties of bitumen and mixture morphology which is a combined effect of aggregate packing, porosity, air void distribution and their interconnectivity. Thus, a clear understanding on the physicochemical properties of bitumen and mixture morphology may help to predict the performance of asphalt mixtures, which will contribute to longer-lasting and better performing pavements. When looking at the bitumen at micro-scale, one can see microstructures appearing under certain conditions which can be partially explained by the interaction of the individual phases. Since the thermo-rheological behavior of bitumen depends largely on its chemical structure and intermolecular microstructures, studying these can lead to understanding of the mechanism, speed and conditions under which this phase behavior occurs. Linking this to the changes in properties of bitumen can thus lead to better understanding of the causes of ageing, its dominant parameters and the resulting diminished mechanical response. To investigate ageing in asphalt pavements, along with physicochemical properties of bitumen one needs to also focus on the influence of mixture morphology.  It is known that asphalt mixtures with similar percentages of air-voids can have different morphologies and thus can age differently. Prediction of ageing behavior without considering the influence of mixture morphology may thus lead to erroneous conclusions and non-optimal mix design. Hence, it is important to understand the interplay between the mixture morphology and ageing susceptibility and relate this to the long term mixture performance. The aim of this Thesis was to develop fundamental understanding on ageing in asphalt mixtures that can contribute to the asphalt community moving away from the currently used accelerated ageing laboratory tests and empirical models that can lead to erroneous conclusions. To reach this aim, experimental and numerical micro-scale analyses on bitumen and meso-scale investigations on mixture morphology have been performed which, collectively, allowed for the development of a method for the prediction of asphalt field ageing, incorporating both mixture morphology and micro-scale bitumen mechanisms. For this, first, the mechanisms of surface ageing and diffusion controlled oxidative ageing were identified. Secondly, the influence of mixture morphology on asphalt ageing susceptibility was investigated. Procedures to determine the controlling parameter were then developed and an empirical framework to quantify the long-term field ageing of asphalt mixtures was set-up. For this, a combination of experimental and numerical methods was employed. An extensive experimental study was carried out to understand the fundamental mechanisms behind the micro-structural phase appearance and the speed or mobility at which they change. Atomic Force Microscopy (AFM) was utilized at different temperatures to investigate the phase separation behavior for four different types of bitumen and co-relate it with the Differential Scanning Calorimetry (DSC) measurements. Based on the experimental findings, it was concluded that the observed phase separation is mainly due to the wax/paraffin fraction presence in bitumen (Paper I). A hypothesis was developed of the appearance of a thin film at the specimen surface due to ageing which is creating a barrier, restricting thus the microstructures to float towards the surface. Furthermore, investigation showed that depending on the bitumen and exposure types this surface thin film is water soluble and thus the moisture damage becomes more severe with the ageing of asphalt pavement (Paper II and IV). A new empirical relation to obtain the primary structure coating thickness was established utilizing mixture volumetric properties and gradation using a large set of data from different literature sources. It was found that the enhanced morphological framework can be used to optimize the long term performance of asphalt mixtures (Paper III).  Thereafter, the effect of diffusion controlled oxidative ageing on different mixture morphologies based on oxidative ageing mechanism of bitumen and diffusion-reaction process was investigated using the Finite Element Method (FEM). From the FE analyses, the effect of air-void distribution and their interconnectivity combined with the aggregate packing was shown to have a significant effect on age hardening (Paper IV). It was shown that focusing only on the percentage of air-void as the main predictive ageing parameter may lead to an erroneous conclusion and non-optimal predictions of long-term behavior.  To replace such approaches, a new way to predict the long-term ageing was proposed in this Thesis, utilizing the found influences of mixture morphology and fundamental mechanism. Though additional mechanisms and non-linear coupling between them may be still needed to reach the ‘ultimate’ ageing prediction model, the current model was found to be a significant improvement to the currently used methods and may lead the way towards further enhancing the fundamental knowledge towards asphalt mixture ageing (Paper V). / <p>QC 20140509</p>

Des matériaux hydrocarbonés façonnés par l'homme ont abondamment été découverts sur les sites du Proche-Orient ancien. Ces matériaux incluent du bitume visqueux suintant le long des rivières ou sur les falaises, des calcaires bitumineux, des sables bitumineux et des asphaltites. Le champ d'utilisation est vaste et regroupe plusieurs qualités physicochimiques mises à profit : adhésivité, imperméabilisant, conservation, poids, couleur noire, matière malléable ou sculptable. L'étude des modes d'exploitation et du cadre technique, menée sur un cadre chronologique couvrant le milieu du 6e au 3e millénaires av. J.-C. en Mésopotamie, au Khuzestân et en Arabie orientale, a permis d'apporter de nouvelles données sur la dynamique culturelle des sociétés proche-orientales. Cette approche axée sur l'homme et la matière n'avait jamais été entreprise auparavant sur ce matériau. Cette recherche est fondée sur un corpus de 4021 bitumes répartis sur 101 sites archéologiques. Les objets et fragments ont été classés suivant leur domaine d'utilisation permettant ainsi d'identifier plusieurs aires techniques. L'étude technologique, réalisée grâce à une approche pluridisciplinaire (archéométrie, ethnographie, épigraphie, expérimentation), restitue des chaînes opératoires pour l'exploitation des bitumes visqueux ou solides. Les textes cunéiformes de la fin du 3e millénaire témoignent de métiers dédiés au façonnage des bitumes, de leur prix et d'une hiérarchisation des sites au sein de leur exploitation. Les modèles de diffusion des techniques identifiés dans cette recherche mettent en évidence l'existence de foyers d'invention dans presque tout l'ensemble du Proche-Orient ancien. / Man-shaped hydrocarbonated materials have been widely discovered in ancient Near East archaeological sites. These materials include viscous bitumen seeping along rivers and cliffs, bituminous limestones, bituminous sands and asphaltites. Adhesiveness, impermeability, conservation, weight, dark color, ductility or sculptability are among the variety of physico-chemical characteristics which allow for a large scope of use. Research on bitumen exploitation methods and corresponding technical framework covers a timeframe from mid 6th to 3rd millennia B.C. over Mesopotamia, Khuzistan and Eastern Arabia. This study, focusing on man and bitumen materials, was never performed before and provides new valuable insights in relation to Near East societies cultural dynamics. We gathered and brought together a comprehensive and organized database composed of 4021 bitumen items from 101 different archaeological sites. The bitumen pieces, artifacts and fragments are presented following their scope of use thus allowing the identification of technical fields. The technological study was based on a pluridisciplinary approach including archeometry, ethnography, epigraphy and experimentation; it brings to light viscous or solid bitumen exploitation operational chains. Cuneiform texts from end of 3rd millennium testify bitumen professions and occupations, bitumen prices and a hierarchy of sites within their exploitation. The techniques spreading models identified in our research highlight the existence of invention spots in almost all ancient Near East.

Canada has become increasingly economically dependent on the exportation of bitumen to trans-oceanic international markets. As the export of Alberta bitumen from ports located in British Columbia increases, oil spill response and readiness measures become increasingly important. Although the frequency of ship-source oil spills has dramatically declined over the past several decades, they remain environmentally devastating when they occur. In the event of a marine spill, great lengths of shoreline are at risk of being contaminated. Once ashore, oil can persist for decades if shoreline hydraulic conditions are correct and remediation does not occur. Most commonly transported oils (e.g., fuel oils, Bunker C, crude oil, etc.) have been thoroughly studied, and their fate and behaviour in the event of a marine spill is well understood. In contrast, because diluted bitumen has been historically traded in relatively low quantities and has almost no spill history, there is a sizable knowledge gap regarding its effects and behaviour in both the marine environment and on coastal shorelines. The intent of this thesis was to develop a classification scheme to identify marine shorelines of high and low diluted bitumen (dilbit) retention for southeastern Vancouver Island, British Columbia. This study builds upon the outcome of former laboratory bench top dilbit and sediment research known as Bitumen Experiments (Bit_Ex). Bit_Ex investigated dilbit penetration and retention in six engineered sediment classifications ranging from coarse sand to very large pebble in accordance with the Wentworth Classification scheme. This research used Bit_Ex findings to predict dilbit retention in poorly sorted in-situ beach sediments found on shorelines representative of the southern coast of Vancouver Island, British Columbia, Canada. Field and laboratory measurements were conducted to document the occurrence of in-situ shoreline sediments and hydraulic conditions and were used to predict dilbit retention by comparing such characteristics between Bit_Ex and unconsolidated in-situ beach sediments. Saturated hydraulic conductivity (Ks) was measured using a double-ring constant-head infiltrometer. Measured Ks values were then compared to predicted Ks values generated by five semi-empirical Ks equations. A modified version of the Hazen Approximation was selected as the most appropriate. Using measured and calculated metrics, sediments were grouped as having either low or high dilbit retention. When sediments were analysed as homogenous samples, the experimental results suggested two of ten shorelines were composed of a combination of low and high retention sections, while the remaining eight sites were of low retention. Upon the isolation of coarse surface strata, results indicated two shorelines were entirely veneered with high retention sediments, and four shorelines were a combination of high and low retention. The residual four shorelines were found to be entirely composed of low retention sediments. The results illuminate the importance of shoreline stratification when predicting shoreline oil retention. This characteristic is a factor that current shoreline oil retention mapping techniques do not adequately consider. Additionally, the findings suggest that while sediments indicative of retaining weathered dilbit are relatively uncommon within Juan de Fuca and Harro Straits, high retention unweathered dilbit sediments are more common. / Graduate / 2018-06-26

L'étude des surpressions de fluide et de fracturation hydraulique des roches mères peut nous renseigner sur les mécanismes de génération qui en sont à l'origine. Ces dernières années, l'intérêt pour ces phénomènes s'est largement accru, notamment sous l'influence des sociétés pétrolières qui exploitent les ressources non-conventionnelles au cœur des problèmes énergétiques actuels. Dans ce travail de thèse, nous avons choisi deux approches différentes pour l'étude de ces mécanismes : (1) des exemples de cas géologiques naturels, et (2) le développement de la modélisation analogique. Ainsi, nous montrons que ces phénomènes sont très répandus au sein des bassins sédimentaires et que leurs manifestations s'expriment notamment par la génération de veines fibreuses parallèles à la stratification de la roche (beef), mais également par la formation de veines d'hydrocarbures solides (bitume). Nous démontrons également que les surpressions de fluides peuvent profondément changer le style de déformation d'un bassin sédimentaire par la génération de niveaux de décollement localisés au sein même des roches mères. Enfin, à l'aide de la modélisation analogique, nous avons pu identifier les mécanismes à l'origine des surpressions de fluide et de la fracturation hydraulique. En effet, lors de la génération d'hydrocarbures la transformation de solide à liquide de la matière organique conduit à la compaction chimique des sédiments. Par un mécanisme de transfert de charge lors de ce processus, ainsi que par l'accroissement de volume associé, des surpressions de fluides se développent et atteignent des pressions lithostatiques, capables de fracturer hydrauliquement les roches. / The study of fluid overpressures and hydraulic fracturing in source rocks can help us to understand the mechanisms, which are responsable for these phenomena. During the last few years, the interest in such processes has highly grown, especially through the influence of petroleum companies, which extract hydrocarbons from unconventional reservoirs. In this work, we have chosen to develop two different approaches for the study of these mechanisms: (1) field studies and (2) physical modelling. Thereby, we show that fluid overpressures and hydraulic fracturing are common in sedimentary basins worldwide. Bedding-parallel fibrous veins (beef) and solid hydrocarbon veins (bitumen) are the resulting structures. We also show that fluid overpressures can highly affect the deformation style in sedimentary basins, especially by causing thrust-detachments within source rocks. By the using of a new physcial modelling technique, we have identified the mechanisms, which are responsible for fluid overpressures and hydraulic fracturing. Indeed, during hydrocarbon generation, the solid organic matter becomes liquid, which leads to chemical compaction of the sediment. By a mechanism of load transfer, fluid overpressures rise to lithostatic values. However, volume changes also contribute, and are able to induce hydraulic fractures in the rocks.

The current shortage of crude oil from conventional sources has increased interest in developing unconventional resources such as oil sands. Heavy crudes and bitumen are found in Northern Alberta and their exploration, processing, and transport to market pose challenges in the use of these resources. Part of the solution to these challenges involves the reactive thermal processing of heavy crudes and bitumen. This thesis focused on mild thermal cracking reactions, and two studies regarding these reactions were presented. The first was an experimental study performed in a pilot-scale semi-batch reactor. The three crude oils were heated to 350, 400, 425, and 450°C at 1240 kPa. A five-lump reaction model combined with a process simulator with VLE calculations was fitted with the experimental data obtained. The goodness of fit between the model predicted values and experimental values for the Hardisty (MBL), Albian Heavy Synthetic (AHS), and Christina Lake Dilute Bitumen (CDB) were determined to be 0.99, 0.99, and 0.98, respectively. Moreover, 80, 85, and 89% of the optimized model’s predicted values had less than 10% error for MBL, AHS, and CDB, respectively. The second study described the implementation of a mild thermal cracking reaction model to the development of a train car fire-model for the assessment of safety aspects in the design of train cars used to transport crude oil. Case studies were conducted using the UniSim® depressuring utility and a previously developed mild thermal cracking reaction model to demonstrate the effect of compositional change. Three crude oils with varying properties and representative of the types of crudes transported by rail in Canada were used here: MBL, AHS, and CDB. The case studies conducted showed the performance of a train car fire-model to be dependent on the crude oil characteristics: up to -57% and -99% difference in model predicted variables for AHS and CDB, respectively, when compared to MBL. Furthermore, the model’s performance was also shown to be affected by the compositional change of a given crude oil due to mild thermal cracking reactions: up to 42% difference in model predicted variables when compared to the base case.

The aim of this diploma thesis is theoretical knowledge of the problems rich bottom layer and practical part of comparison of three asphalt mixtures for base layers using common road bitumen and modified rubber granulate. Selected functional laboratory tests (low temperature, fatigue resistance, bulk density) and stiffnes modules are performed on these mixtures and the results are compared to each other.