The introduction of the use of Tire Pressure Control Systems (TPCS) to improve the productivity of the Canadian trucking industry is gaining momentum. The imposition of seasonal load restrictions (SLR) on the thaw-weakened secondary roads interrupts the transportation of raw materials to processing facilities For the forestry industry in particular, this has very significant impacts on productivity and costs. FPInnovations-Feric Division (Feric) has investigated the potential for TPCS-equipped trucks to travel with full, legal loading during the SLR period without accelerating road wear and tear. The TPCS monitors and adjusts the inflation pressure of the trucks’ tires while driving and allows the operator to optimize the inflations for changes in loading, travel speed, or road quality encountered in the trip. This thesis describes an investigation to determine whether TPCS can be used to mitigate traffic generated damage to secondary roads and also reduce the need to implement load restrictions. The project involves a partnership with the Ontario Ministry of Transportation Ontario (MTO), Forest Engineering Research Institute of Canada (FERIC), Ontario Ministry of Natural Resources (MNR) and the Centre for Pavement and Transportation Technology (CPATT) located at the University of Waterloo. The thesis will describe the methodology, design, and instrumentation of the two test sites which are located in Dryden, Ontario and Chapleau, Ontario. In addition, repeated Portable Falling Weight Deflectometer (PFWD) testing is being carried out at these sites and the initial results of this examination and associated impacts of the environment and traffic on the road will be presented. This study also involves looking into the reliability of using the portable FWD, offering a lower cost alternative instead of the trailer mounted FWD to monitor pavement strength for the identification the SLR period. The use of innovative sensors and data collection techniques are proving to be very informative and are advancing pavement engineering knowledge. Moreover, the thesis is aimed at exploring the possibilities of achieving the current objectives of the government DOTs such as TPCS potential for addressing the timber industry in crisis, reduced road maintenance budgets, and global warming increasing road damage.

Self consolidating concrete (SCC) is defined as an innovative concrete that does not require vibration for placing and compaction and it is able to flow under its own weight, completely filling formwork and achieving full compaction. Although significant amount of research has been carried out regarding the fresh properties, mix design, placing methods and strength of various SCC mixes, only a very limited amount of work has been done to assess the durability performance of SCC. Concretes in cold climates are subjected to freeze-thaw cycles which are one of the major durability problems, and if the concrete is in a saturated or nearly saturated condition, those cycles lead to expansion of the water in the capillary pores of concrete causing great internal stresses. For a durable concrete subjected to freeze-thaw cycles, an adequate air void system is obtained by using air-entraining admixtures. The performance of the air void system is characterized by air void parameters that are determined using microscopical examination of the concrete microstructure. In this thesis a software tool, based on image analysis of concrete surface, is developed to evaluate the air void parameters of concrete using both American and European standards. Later on, an experimental program is conducted to evaluate the effect of freezing-thawing on self consolidating concrete that contain different percentages of fly ash (FA) and air entraining agents. For this purpose, a total of ten self consolidating concrete mixtures that contain four different contents of fly ash, and three different levels of air entrainment were prepared. During the casting operation, the workability properties of SCCs were observed through slump flow time and diameter, air content, V-funnel flow time, L-box height ratio, and segregation ratio. Hardened properties were evaluated by compressive strength, permeability tests (water absorption, sorptivity and rapid chloride permeability test), freezing-thawing test, resonant frequency test, ultrasonic pulse velocity test. The developed tool was used to characterize and evaluate the effects of air void parameters of SCC on its resistance to freeze-thaw cycles. At the end of this experimental investigation, it was concluded that the addition of air entraining agent increased the flowability and an increase in the fly ash content decreased the effect of air entraining agent. On the other hand, during image processing, it was observed that the surface preparation procedures have a crucial effect on processing quality. Moreover, spacing factor -which is the most important air void characteristic that is utilized for determination of the resistance to freezing-thawing- should not be restricted to 0.2 mm for SCC, since SCCs with spacing factors smaller than 0.4 mm could still exhibit good freezethaw resistance.

207Pb*/206Pb* chronometry was used to obtain the ages of Ca,Al-rich inclusions (CAIs) and chondrules found in ancient meteorites. Assuming a 238U/235U=137.88, Pb/Pb ages of chondrules in NWA801 (a CR2 meteorite) are 4564.6±1.0 Ma, chondrules in Mokoia (a CV3 chondrite) are 4564.2±1.1Ma, and CAIs in Mokoia are 4567.9±5.4 Ma. The Pb/Pb age of NWA801 chondrules is concordant with 26Al/26Mg ages of CR chondrules. However if a 238U/235U < 137.88 is used, the age for NWA801 chondrules becomes younger by ~1Ma and discordant with 26Al/26Mg ages of CR chondrules. This suggests either a discrepancy with the U compositions or the initial Mg isotopic compositions of NWA801 chondrules. The shapes of NWA801 chondrules, and blebs of FeNi metal in the meteorite matrix, were further studied by 3D X-ray micro-computed tomography (CT). Most chondrules (92%) were ‘armoured’ with one discontinuous layer of FeNi metal. Two layers of FeNi metal (one on the exterior and one concentric through the interior separated by silicate) were rare <8%. Chondrules and matrix blebs occur as oblates, prolate, spheres and triaxial spheroids. It is proposed that the shapes were made free-floating in the nebula likely by flash-melting precursors into molten droplets that were vibrating as harmonic oscillators that ‘froze-in’ their shapes during cooling. Parent-body metamorphism and shock are not likely processes affecting the matrix-bleb and chondrule shapes. Chondrules with ≥2 FeNi metal layers were likely formed by mergers and not by successive deposition and annealing of metal in multiple flash-melting events. Attempts to obtain 207Pb*/206Pb* ages from chondrules and CAIs by thermal extraction (TE)- TIMS were unsuccessful. However LA-ICP-MS was shown to be useful for rapidly determining Pb isotopic trends in meteorites and unknown objects. In particular, it was shown that 137La (T1/2=60ky) should be detectable in recently fallen meteorites using LaF−4 to suppress the 137Ba isobar during tandem accelerator mass spectrometry combined with a novel instrumental technique for isobar separation.

207Pb*/206Pb* chronometry was used to obtain the ages of Ca,Al-rich inclusions (CAIs) and chondrules found in ancient meteorites. Assuming a 238U/235U=137.88, Pb/Pb ages of chondrules in NWA801 (a CR2 meteorite) are 4564.6±1.0 Ma, chondrules in Mokoia (a CV3 chondrite) are 4564.2±1.1Ma, and CAIs in Mokoia are 4567.9±5.4 Ma. The Pb/Pb age of NWA801 chondrules is concordant with 26Al/26Mg ages of CR chondrules. However if a 238U/235U < 137.88 is used, the age for NWA801 chondrules becomes younger by ~1Ma and discordant with 26Al/26Mg ages of CR chondrules. This suggests either a discrepancy with the U compositions or the initial Mg isotopic compositions of NWA801 chondrules. The shapes of NWA801 chondrules, and blebs of FeNi metal in the meteorite matrix, were further studied by 3D X-ray micro-computed tomography (CT). Most chondrules (92%) were ‘armoured’ with one discontinuous layer of FeNi metal. Two layers of FeNi metal (one on the exterior and one concentric through the interior separated by silicate) were rare <8%. Chondrules and matrix blebs occur as oblates, prolate, spheres and triaxial spheroids. It is proposed that the shapes were made free-floating in the nebula likely by flash-melting precursors into molten droplets that were vibrating as harmonic oscillators that ‘froze-in’ their shapes during cooling. Parent-body metamorphism and shock are not likely processes affecting the matrix-bleb and chondrule shapes. Chondrules with ≥2 FeNi metal layers were likely formed by mergers and not by successive deposition and annealing of metal in multiple flash-melting events. Attempts to obtain 207Pb*/206Pb* ages from chondrules and CAIs by thermal extraction (TE)- TIMS were unsuccessful. However LA-ICP-MS was shown to be useful for rapidly determining Pb isotopic trends in meteorites and unknown objects. In particular, it was shown that 137La (T1/2=60ky) should be detectable in recently fallen meteorites using LaF−4 to suppress the 137Ba isobar during tandem accelerator mass spectrometry combined with a novel instrumental technique for isobar separation.

This project concerns the effect of freeze-thaw cycles on the pore-scale structure of nonaqueous phase liquid (NAPL) contaminants in water-saturated porous media. This problem is of critical importance to the entrapment of such contaminants in cold temperate, polar and high altitude regions, and has not been examined in the literature to date. This research work is conducted in three stages: (i) two-dimensional nondestructive visualisation of residual light non-aqueous phase liquid (LNAPL), and dense non-aqueous phase liquid (DNAPL), in porous media subject to successive freeze-thaw cycles; (ii) three-dimensional experiments on LNAPL in porous media subject to freeze-thaw, with quantification of phase volumes by X-ray micro-computed tomography (micro-CT); and (iii) the explanation of results by several pore scale mathematical and conceptual models. The two-dimensional cell experiments (using a monolayer of 0.5 mm diameter glass beads held between two glass sheets), and three-dimensional X-ray micro-CT experiments reveal a substantial mobilisation and rupture of ganglia during successive freeze-thaw cycles; this includes the detachment of smaller ganglia from larger ganglia and the mobilisation of NAPL in the direction of freezing front. The experiments also reveal significant shedding of numerous single/sub-singlet ganglia along narrow pore corridors, their entrapment in growing polycrystalline ice, and the coalescence of such small ganglia during thawing to form larger singlets. These changes were more predominant where the freezing commenced. The results of the experimental studies were interpreted by developing several mathematical and conceptual models, including freezing-induced pressure model, Darcy's law model, multipore ganglia model (rupture coefficient) and ice-snap off model.

Les enrobés bitumineux sont des matériaux composites complexes constitués de plusieurs phases : granulats, liants bitumineux et vides. L'assemblage de ces phases définit une microstructure très complexe qui pilote la réponse macroscopique des enrobés. Classiquement, les réponses mécanique et thermique des enrobés sont caractérisées par des essais à l'échelle macroscopique en supposant que le matériau est homogène et isotrope. À l’échelle des constituants, la caractérisation de ces matériaux nécessite d’utiliser une technique de mesure disposant simultanément d’une bonne résolution spatiale et d’une bonne résolution de mesure. L’enjeu de ce travail est d’une part d’évaluer les possibilités d’utilisation de la méthode de la grille (MG) pour l’analyse des propriétés thermo-mécaniques des enrobés bitumineux, et d’autre part de caractériser, grâce à l’apport de cette méthode, l’effet de l’introduction d’agrégats d’enrobés (AE). L’étude expérimentale comprend des essais de compression et de traction ainsi que des essais de gel-dégel. Les champs cinématiques issus de la MG ont permis d'étudier la réponse de ces matériaux à des échelles allant de l’échelle du constituant jusqu’à celle de l’éprouvette. Les résultats obtenus ont également permis de valider une approche expérimentale innovante pour l’analyse des enrobés en permettant d’accéder à des informations fiables et riches à l’échelle de la microstructure. Certains aspects liés à l'impact du recyclage sur le comportement local de l’enrobé sont également fournis. / Asphalt mixtures are complex composite materials constituted of several phases, namely aggregates, bituminous binder and voids. The assembly of these phases defines a highly complex microstructure, which drives the macroscopic response of asphalt mixtures. Classically, both the mechanical and the thermal responses of asphalt materials are characterized by using experiments at the scale of the mixture assuming that the material is homogeneous. At the scale of their constituents, these materials require a measurement technique featuring simultaneously both a good spatial resolution and a good strain resolution. To date, there are only few experimental studies available in the literature that describe the thermal and mechanical behavior of bituminous mixes at the scale of the constituent. The aim of this work is, on the one hand, to evaluate the possibilities of using the grid method (GM) for the analysis of the thermo-mechanical properties of asphalt mixtures and, on the other hand, to characterize the effect of the recycled asphalt pavement (RAP) inclusion on the local behavior of these materials. Full-field measurements provided by GM allow to study the response of these materials at scales ranging from the component to the mixture itself. These results enable us to validate an innovative experimental approach for the analysis of asphalts. It gives access to reliable and rich information at the scale of the microstructure. Some aspects related to the impact of RAP on the local behavior of asphalt were also provided.

Abstract This PhD thesis is composed of a synopsis and five published papers that are focused on both the research results of studies on electrical properties of road materials and subgrade soils and their seasonal changes and the use of Ground Penetrating Radar technique in traffic infrastructure surveys. The data for this survey was collected mainly in Finland, Texas, Scotland and Sweden and thus presents many kinds of road materials, subgrade soils and climate conditions. The synopsis of this work begins with a presentation of the theory and basic principles of GPR techniques. Special attention is given to the dielectric properties and seasonal changes of unbound road materials and subgrade soils. The synopsis also presents different kinds of GPR hardware systems as well as recommendations and experiences from different data collection, processing and interpretation techniques. Special attention is given to a method whereby GPR data is integrated with other road survey data and then analysed using a number of structural diagnostic methods. Finally, the synopsis provides an overview of of the various GPR applications on roads and streets, bridges, railways and airports. The laboratory test results presented in this work show that the relationship between dielectric value and increasing water content is not linear or exponential but more likely a series of logarithmic functions. Laboratory results also showed that dielectric dispersion, which can be related to poorly performing subgrade soils and road aggregates, takes place mainly in loosely bound adsorption water and capillary water layer. As such these moisture sensitive problem materials can also be identified during the dry summer seasons when they are stiff. Dielectric value and electrical conductivity can also be related to other technical properties of road materials and subgrade soils such as frost susceptibility, shear strength, plastic limit, compaction degree and voids content. Laboratory tests and field data collected using the Percostation technique also demonstrate that a knowledge of seasonal changes and thermodynamics is very important in understanding and modelling the mechanical behaviour of road structures. Finally, laboratory and field tests indicate that colloids have an important role in the failure mechanism of the road materials. This research demonstrates that the GPR technique not only gives valuable structural information on the different types of structures and subgrade soils but it provides a wide range of information of the electrical properties of the materials under survey which can be further related to their mechanical performance. The best information will be gained if GPR data is analysed together with other non destructive testing data collected form the roads, railways and airports.

During the industrialization of the 19th century the negative health effects of vitamin D was discovered as children in the cities developed osteomalacia or more commonly known as rickets caused by vitamin D deficiency. Vitamin D is produced in the skin from 7-dehydrocholesterol during sun-exposure and enhances intestinal phosphor and calcium absorption thus enhancing the bone remodeling process. Now, in the 21st century, Vitamin D is still relevant as positive health effects have been recognized and with it an increased number of samples and a demand for accurate analyzing. Vitamin D is commonly believed to be sensitive to ultraviolet radiation in serum and blood samples and therefore have traditionally been kept protected from light exposure from the time of sampling until the finished analyze. However recent studies have proven 25- hydroxyvitamin D (25[OH]D) to be stable in both whole blood and serum. As previous studies have been primarily conducted in research laboratories with the aim to study vitamin D under specific research-laboratory conditions the aim of this study was to study the stability of 25[OH]D in serum and whole blood within both primary care- and hospital laboratories under normal and exaggerated conditions with the purpose to evaluate possible pre-analytical issues with everyday handling processes. The assay used was high pressure liquid chromatography-tandem mass spectrometry, HPLCMS/MS, and the sought analytes 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3, 25[OH]D2 and 25[OH]D3. The results showed that 25-hydroxyvitamin D is stable in serum for 24 hours at room temperature whilst exposed to light both ultraviolet and fluorescent. The analyte is also stable for up to four freeze-thaw cycles rendering the process of light-protection and samples frozen immediately after centrifugation superfluous. The results also ensure reliable results even if samples are accidently left on benchtops or saved refrozen to be reanalyzed at a later date. / Under den industriella revolutionen på 1800 talet upptäcktes de negativa hälsoeffekterna av vitamin D-brist då barnen i städerna utvecklade rakit (osteomalaci) eller engelska sjukan som sjukdomen också kallas på grund av brist på sol och D-vitamin. Vitamin D produceras i huden från 7-dehydrokolesterol vid solexponering och ökar upptaget av fosfor och kalcium i tarmen som i sin tur förbättrar återuppbyggnaden av skelettet. Vitamin D är fortfarande aktuell även nu i vår tid men då för dess nyupptäckta hälsofrämjande egenskaper som till exempel förebyggandet av coloncancer. Detta medför även en ökning av antalet analyser och kräver därmed en adekvat analysmetod. Traditionellt har det antagits att vitamin D är ljuskänsligt i alla former därför har blod och serum ljusskyddats, från provtagningstillfället fram tills dess att analysen är utförd. Dock har nya studier visat att 25-hydroxyvitamin D (25[OH]D) är mycket stabilt bundet till vitamindbindande protein i både serum och helblod. Syftet med studien var att utvärdera om 25[OH]D i serum och helblod behöver ljusskddas genom att studera stabiliteten hos 25[OH]D i både serum och helblod under normala primärvårdslaboratorie- och sjukhuslaboratorieförhållanden samt under extrema förhållanden för att utvärdera eventuella preanalytiska problem eller fel relaterade till den vardagliga hanteringen av vitamin D prover. Proverna analyserades med högupplösande vätskekromatografi-tandem masspektrometri, HPLC-MS/MS, och de sökta analyterna var 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3, 25[OH]D2 och 25[OH]D3. Resultat från studien visade att 25-hydroxyvitamin D är stabilt i serum i 24 timmar i rumstemperatur med ljusexponering från både ultraviolett och fluorescerande ljus. 25-hydroxyvitamin D är även stabil i serum upp till fyra frys- och tiningscykler. Detta gör att provhanteringen kan förenklas genom att dessa prover inte behöver ljusskyddas samt att serumet ej behöver frysas in direkt efter centrifugering. Resultatet säkerställer även tillförlitliga resultat om prover lämnas framme på bänken av misstag eller om prover behöver sparas och frysas om för att analyseras vid senare tillfälle.

Cement-based concrete is one of the main construction materials that is widely used for many construction applications due to its strength, durability, reflectivity, and versatility. However, it is acknowledged that production of cement as a primary material of concrete releases 1.8 Gt carbon dioxide (CO2) into the environment. It is estimated that one ton of cement production releases one ton of CO2 to the atmosphere. That is why, this work aims to create a concrete that could be an alternative to cement-based concrete. Geopolymer concrete (GPC) is an eco-friendly construction material and an alternative to conventional concrete that is produced by reacting aluminate and silicate bearing constituents with a caustic activator (i.e. sodium-based or potassium-based). Both potassium and sodium have been considered as generally safe intergradient by the FDA, based upon the observance of several good manufacturing practice conditions of use. Theses activators are used in various application including concrete, food, as a stabilizer, and as a thickening agent. Moreover, these activators are also used in making soap, as an electrolyte in alkaline batteries and in electroplating, lithography, and paint and varnish removers. Medically, these activators are widely used in the wet mount preparation of various clinical specimens for microscopic visualization of fungi and fungal elements in skin, hair, nails, and even vaginal secretions, Currently, it was determined that these activators solution were found to be a safe and effective treatment of plane warts. Despite the developments in the studies relating to GPC made by various precursors such as fly-ash and slag in the literatures, the use of GPC made by fly-ash and bottom-ash has not been overly researched. In this study, attempts have been made to produce a unique mix proportion for Potassium-based GPC made by fly-ash and bottom-ash and investigate various mechanical properties of this type of GPC including elastic modulus, freeze-thaw resistance, heavy metal leach-ability and corrosion in both laboratory and real environmental conditions using Non-Destructive Tests (NDT)s. / Graduate / 2021-12-15

The thesis is focused on possibilities of durability evaluation of surface layer of concrete structures. The durability of concrete surface layer usually determines the durability of the structure as a unit. It has to be determined in what environment the structure is situated and what influences it has to face, to set the durability of the structure. There is a several normative prescription to set the resistance of the structure. There is formulated a summary of the most widely used and known prescriptions in the theoretical part of the thesis. It is a lot of effort to estimate the durability of the concrete by estimation of permeability of the concrete surface layer recently. Thus these methods are also formulated in the summary and there are compared the individual outputs of the tests. The permeability and pore structures of the concrete surface layer are crucial parameters for the durability of concrete structure. These parameters influence the construction properties of the concrete as well, thus the thesis is focused on relationship of the pore structure and the strength in press of the concrete.