Heard Island is a remote Australian territory which lies in the South-middle sector of the Indian Ocean.The island lies in the central province of the Kerguelen Plateau. On the north-western face of the islandlies the Laurens Peninsula, where modern volcanism has been periodic since approximately 10 ka, butno eruption has been recorded. The main volcanic feature of the peninsula is Mt Dixon of which noactivity has been observed but it is thought to have erupted within the past few hundred years. This thesis applied the crystal size distribution method to three thin sections from the LaurensPeninsula. The samples were collected from a phonolite from Jacka valley, a teprhiphonolite from thebase of the Red Island cone, and a tephrite east of Cape Cartwright. Crystal dimensions were calculatedusing ImageJ Fiji, these dimensions were corrected for 3D dimensions using CSDslice, and the datawas plotted using CSDcorrections. Microcrysts were traced using backscattered electron (BSE) images,and high resolutions scans of the thin section were used to trace phenocrysts. The results of the crystalsize distributions show concave-up shapes in all plots with steep slopes for smaller crystals, followedby shallow slopes for larger crystals. This suggests binary magma mixing by replenishment occurred inthe magmas associated with all three samples. The different slopes suggest two separate crystallisationconditions: Phenocrysts crystalized slowly in the chamber and microcrysts crystallized relativelyquickly during or after eruption. Textural differences in the three samples suggest that the tephrite hadthe longest residence time and underwent the most replenishment events, followed by thetephriphonolite and lastly the phonolite. Finally, since replenishment is the mechanism of mixingbeneath the Laurens Peninsula, then volcanism might still be active, and the chambers could currentlybe replenishing, which could trigger an eruption. / Heard Island är ett avlägset australiensiskt territorium som ligger i den södra delen av den Indiskaoceanen. Ön ligger i den centrala provinsen på Kerguelenplatån. På den nordvästra sidan av ön liggerLaurens-halvön, där modern vulkanism daterar sig till cirka 10 ka. Den främsta vulkaniska strukturenpå halvön är Mt Dixon där ingen aktivitet har registrerats, men som tros ha haft ett utbrott under desenaste hundra åren. Denna avhandling tillämpade metoden för kristallstorleksfördelning på tre tunnslipar frånLaurenshalvön. Proverna samlades in från en fonolit från Jacka valley, en tefrifonolit från basen av RedIsland cone och en tefrit öster om Cape Cartwright. Kristalldimensioner beräknades med ImageJ Fiji,dessa dimensioner korrigerades för 3D-dimensioner med CSDslice, och datat plottades medCSDcorrections. Mikrokristaller spårades med hjälp av backscattered electron images (BSE) ochhögupplösta skanningar av tunnslipen användes för att spåra fenokryster. Resultaten avkristallstorleksfördelningarna föreslog binär magmablandning via påfyllning i alla tre proverna. Dessavisade konkava former i alla plotter med branta sluttningar för mindre kristaller, följt av plattaresluttningar för större kristaller. De olika lutningarna på kurvorna föreslog två separatakristallisationsförhållanden: fenokryster kristalliserade långsamt i kammaren, och mikrokristallerkristalliserade relativt snabbt under eller efter utbrottet. Texturella skillnader i de tre proverna antyddeatt tefriten hade den längsta residenstiden och genomgick flest påfyllningshändelser, följt avtefrifonoliten och slutligen fonoliten. Slutligen, om påfyllning var mekanismen för att blandas underLaurenshalvön, så kan vulkanismen fortfarande vara aktiv, men för närvarande i ettpåfyllningsuppehåll.

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Fatigue and ductility properties in various tool steels, produced by powder metallurgy, spray forming or conventionally ingot casting, have been analysed experimentally and successfully compared to developed models. The models are able to predict the fatigue limit and cause for fatigue fracture, and strain- and stress-development until fracture during the ductile fracture process respectively. Total fracture in a tool steel component, both in fatigue and ductility testing, is caused by a propagating crack initiated by particles, i.e. carbides or non-metallic inclusions. The models are based on experimentally observed size distributions. The axial fatigue strength at two million cycles was determined for various tool steels. The fracture surface of each test bar broken was examined in SEM to determine the cause for fatigue failure, i.e. a single carbide or inclusion particle or a cluster of carbides, and the size of the particle. The particles act as stress concentrators where a crack is easily initiated when the material is subjected to alternating stresses. The developed models calculate the probability that at least one particle will be present in the material which is larger than the threshold level for crack initiation at a certain stress range. The ductility testing was performed on various tool steels by four-point bending under static load. The load and displacement until total fracture were recorded and the maximum strain and stress acting in the material were calculated. The fracture surface of each broken test bar was examined in SEM, though the crack initiating area appears different compared to a fatigue failure. Ductile fracture is caused by a crack emanating from voids nucleated around many particles in a joint process and then linked together. By finite element modelling of void initiation and propagation in 2D of an experimentally observed carbide microstructure for each tool steel, successful comparisons with experiments were performed. Carbides were modelled as cracked when larger than a certain size, based on fracture surface observations, and the matrix cracked above a pre-defined plastic deformation level. The stresses and strains at total failure were in good agreement between model and experiments when evaluated. The use of these developed models could be a powerful tool for optimisation of fatigue and ductility properties for tool steels. With good fatigue and ductility properties normal failures appearing during operation of a tool steel product could be minimised. By theoretical tests in the developed models of various carbide microstructures the optimum mechanical properties could be achieved with a minimum of experiments performed. / QC 20101119

Yes / The tribological performance of the piston assembly of an automotive engine is highly influenced by the complex flow mechanisms that supply lubricant to the upper piston rings. As well as affecting friction and wear, the oil consumption and emissions of the engine are strongly influenced by these mechanisms. There is a significant body of work that seeks to model these flows effectively. However, these models are not able to fully describe the flow of lubricant through the piston assembly. Some experimental studies indicate that droplets of lubricant carried in the gas flows through the piston assembly may account for some of this. This work describes an investigation into the nature of lubricant misting in a fired gasoline engine. Previous work in a laboratory simulator showed that the tendency of a lubricant to form mist is dependent on the viscosity of the lubricant and the type and concentration of viscosity modifier. The higher surface area-to-volume ratio of the lubricant if more droplets are formed or if the droplets are smaller is hypothesised to increase the degradation rate of the lubricant. The key work in the investigation was to measure the size distribution of the droplets in the crankcase of a fired gasoline engine. Droplets were extracted from the crankcase and passed through a laser diffraction particle sizer. Three characteristic droplet size ranges were observed: Spray sized (250–1000 μm); Major mist (30–250 μm); and Minor mist (0.1–30 μm). Higher base oil viscosity tended to reduce the proportion of mist-sized droplets. The viscoelasticity contributed by a polymeric viscosity modifier reduced the proportion of mist droplets, especially at high load.

The collisions frequency of dispersed phases (particles, droplets, bubbles) in a turbulent carrier phase is a fundamental quantity that is needed for modeling multiphase flows with applications to chemical processes, minerals flotation, food science, and many other industries. In this dissertation, numerical simulations are performed to determine collisions frequency of bi-dispersed particles (solid particles and bubbles) in homogeneous isotropic turbulence. Both direct numerical simulations (DNS) and Large Eddy simulations (LES) are conducted to determine velocity fluctuations of the carrier phase. The DNS results are used to validate existing theoretical models as well as the LES results. The dissertation also presents a CFD-based flotation model for predicting the pulp recovery rate in froth flotation machines. In the direct numerical simulations work, particles and bubbles suspended in homogeneous isotropic turbulence are tracked and their collisions frequency is determined as a function of particle Stokes number. The effects of the dispersed phases on the carrier phase are neglected. Particles and bubbles of sizes on the order of Kolmogorov length scale are treated as point masses. Equations of motion of dispersed phases are integrated simultaneously with the equations of the carrier phase using the same time stepping scheme. In addition to Stokes drag, the pressure gradient in the carrier phase and added-mass forces are also included. The collision model used here allows overlap of particles and bubbles. Collisions kernel, radial relative velocity, and radial distribution function found by DNS are compared to theoretical models over a range of particle Stokes number. In general, good agreement between DNS and recent theoretical models is obtained for radial relative velocity for both particle-particle and particle-bubble collisions. The DNS results show that around Stokes number of unity particles of the same group undergo expected preferential concentration while particles and bubbles are segregated. The segregation behavior of particles and bubbles leads to a radial distribution function that is less than one. Existing theoretical models do not account for effects of this segregation behavior of particles and bubbles on the radial distribution function. In the large-eddy simulations efforts, the dissertation addresses the importance of the subgrid fluctuations on the collisions frequency and investigates techniques for predicting those fluctuations. The cases studied are of particles-particles and particles-bubbles collisions at Reynolds number Re_λ = 96. A study is conducted first by neglecting the effects of subgrid velocity fluctuations on particles and bubbles motions. It is found that around Stokes number of unity solid particles of the same group undergo the well known preferential concentration as observed in the DNS. Effects of pressure gradient on the particles are negligible due to their small sizes. Bubbles as a low inertia particles are very sensitive to subgrid velocity and acceleration fields where the effects of pressure gradient in the carrier phase are dominant. However, particle-bubble radial distribution functions from LES are not as low as that from DNS. To account for the effects of subgrid field on the dispersion of particles and bubbles, a new multifractal methodology has been developed to construct a subgrid vorticity field from the resolved vorticity field in frame work of LES. A Poisson's solver is used to obtain the subgrid velocity field from the subgrid vorticity field. Accounting for the subgrid velocity fluctuations (but neglecting pressure gradient) produced minor changes in the radial distribution function for particle-particle and particle-bubble collisions. We conclude from this study that for accurate particle tracking in LES the subgrid velocity fluctuations must be dynamically realizable field (temporally and spatially correlated with the large scale motion). Adding random SGS velocity fluctuations is not enough to capture the correct radial distribution functions of dispersed phases especially for bubbles-particles collisions where the pressure gradient term ( or acceleration Du_f′/Dt) is responsible for particle-bubble segregation around particle Stokes number near one. A CFD-based model for minerals flotation machines has been developed in this dissertation. The objective of flotation models is to predict the recovery rate of minerals from a flotation cell. The developed model advances the state-of-the-art of pulp recovery rate prediction by incorporating validated theoretical collisions frequency models and detailed hydrodynamics from two-phase flow simulations. Spatial distributions of dissipation rate and air volume fraction are determined by the two-phase hydrodynamic simulations. Knowing these parameters throughout the machine is essential in understanding the effectiveness of different components of flotation machine (rotor, stator or disperser, jets) on the flotation efficiency. The developed model not only predicts the average pulp recovery rate but also it indicates regions of high/low recovery rates. The CFD-based flotation model presented here can be used to determine the dependence of recovery rate constant at any locality within the pulp based on particle diameter, particle specfic gravity, contact angle, and surface tension. / Ph. D.

The efficiency of multicrystalline (mc) silicon solar cells depends strongly on the fraction of recombination active crystal defects. This work focuses on a systematic analysis of how the area fraction of recombination active crystal defects and thus the solar cell efficiency is af-fected by the grain structure of mc-silicon wafers, i.e. grain size, grain orientation and type of the grain boundaries between adjacent grains. For that purpose a new characterization method was developed which allows the measurement of the grain orientation and grain boundary type of full 156x156 mm² mc-silicon wafers. The results of the grain structure analysis were correlated with the etch pit density, the recombination active area fraction measured by photo-luminescence imaging, and the solar cell efficiency in order to quantify the most important features of the grain structure, which were relevant to obtain high quality mc-silicon wafer material. For the determination of the grain orientation and grain boundary type two metrology sys-tems were combined. The so-called grain detector determines the geometrical data of each grain (size and form) by a reflectivity measurement. Afterwards the wafer with the geomet-rical information of all grains is transferred into the so-called Laue Scanner. This system irra-diates each grain larger 3 mm² with white x-rays and creates a backscatter diffraction pattern (Laue pattern) for each grain. From this Laue pattern the grain orientation and the grain boundary type of neighboured grains is calculated and statistically analysed in combination with the geometrical data of the grain detector. In this work the grain structure of twelve industrially grown mc-silicon bricks, which were produced by different manufacturers, and two laboratory grown bricks were investigated. Seven of these bricks show a fine grain structure. This material named class F is considered to be typical for so-called High Performance Multi (HPM) silicon. The other bricks show a coarse-grained structure. This grain structure was called class G and corresponds to the con-ventional mc-silicon material. The results show that the grain structures of the start of the crystallization process differ sig-nificantly between class F and class G. The class F mc-silicon wafers have a uniform initial grain size (characterized by coefficient of variation CV¬KG < 2.5) and grain orientation (charac-terized by coefficient of variation CVKO < 1.5) distribution with a small mean grain size (< 4 mm²) and a high length fraction of random grain boundaries (> 60 %) in comparison to the class G wafers. Despite the totally different initial grain structure for the class F and class G bricks, the grain structure of the wafers which represent the end of the crystallization process is more or less comparable. It can be concluded that the development of the grain structure along the crystal height of the class F bricks is driven by an energy minimization due to the surface energy and the grain boundary energy, that means that the share of (111) oriented grains having the lowest surface energy and the share of ∑3 grain boundaries having the lowest interface energy increase from the start of crystallization to the end. This phenomenon could not be observed for the class G bricks, which show a decreasing ∑3 length fraction and a decreasing area fraction of {111} oriented grains. This energetically unfavourable grain structure development is not clear so far but it means another kind of energy minimization effect must exist within class G. This could be for instance the formation of dislocations. The grain structure investigations show clearly that especially the initially fine-grained struc-ture of the class F bricks, i.e. at the start of crystallization, influences beneficially the area fraction of recombination active defects and the solar cell efficiency subsequently. This ob-servation can be explained as follows. Reduced dislocation cluster formation: • The small grain sizes in combination with the low length fraction of ∑3 grain bounda-ries capture the dislocations within a grain. Dislocations are not able to move across the grain boundaries which have not the ∑3-type within moderate stress and tempera-ture fields. This prohibits the formation and expansion of large dislocation cluster. • The previously described energetically driven grain selection and the continuously in-creasing grain size from bottom to top leads to an overgrowth of grains. This means that also dislocated grains will disappear which also prohibits the formation of large dislocation cluster. Reduced possibility of dislocation formation: • Compared to the class G bricks the area fraction of {111} oriented grains is reduced. Therefore, the possibility of the formation of dislocations is reduced, because they would be activated first in {111} oriented grains taking the Schmidt factor in account which is lowest for {111} oriented grains. After the dislocation generation within a {111} oriented grain, the dislocation can move forward on 3 of 4 possible {111} slip planes which have an angle of 19.5° with regard to the growth direction. No other ori-entation has more slip planes for the dislocation movement which have an angle smaller 20° with regard to the growth direction. These arguments in combination with the high reproducibility of the characteristic initial class F structure can explain the observed low recombination active area fraction from start to end of crystallization which was smaller 5 % and especially the low variation of 2 % of the electrical active wafer area in between the class F bricks. One can also easily explain the higher recombination active area fraction up to 14 % and the large variation of 10 % between the class G bricks due to the obtained grain structure data. These differences in the recombination active area fractions are reflected in the solar cell efficiency which is 0.4 % higher for the class F bricks compared to the class G bricks. In consideration of the above mentioned reasons it is not beneficial for the industrial ingot production technology to increase the ingot height further, due to the fact that the advanta-geous initial grain structure properties of class F bricks disappear with increasing crystal height.

Cette étude porte sur le broyage en voie humide (nanobroyage) de produits organiques à usage pharmaceutique dans un broyeur à billes agité. L'objectif des travaux réalisés était d'analyser la faisabilité de l'opération de nanobroyage et d'améliorer la compréhension des processus de réduction de taille dans le cas de produits organiques cristallins. Dans un premier temps, des expériences préliminaires ont été menées pour le choix d'agents mouillants et dispersants adéquats pour les matériaux choisis (ciclopirox, ibuprofène) et pour la mise au point du mode de fonctionnement du procédé de broyage. Nous avons également testé différentes techniques comme la spectroscopie acoustique et la diffusion dynamique de la lumière pour caractériser la distribution de taille des particules broyées, en se basant sur une étude expérimentale conduite sur la calcite, utilisée dans cette étude comme matériau de référence. La seconde partie a été consacrée au broyage par microbilles appliqué aux différents matériaux choisis. Nous avons étudié l'influence des paramètres opératoires tels que le débit de suspension, la vitesse de rotation de l'agitateur, la taille des billes de broyage et la concentration en solide sur l'efficacité énergétique du procédé et la qualité des produits broyés. Les critères de qualité pris en compte dans cette étude sont la distribution de taille des particules, la stabilité et le comportement rhéologique des suspensions broyées ainsi que les propriétés structurales du produit. L'effet du broyage sur les changements microstructuraux des différents produits a enfin été analysé. Une attention particulière a également été portée sur l'effet de la température sur le procédé de réduction de taille et les propriétés de l'ibuprofène broyé. / This work focuses on wet grinding (nanogrinding) of organic materials for pharmaceuticals using a stirred media mill. The aim of the work was to examine the feasibility of nanogrinding process and to improve the understanding of size reduction processes applied on crystalline organic products. Firstly, preliminary investigations were conducted to make a choice of appropriate wetting agents and dispersants for the selected materials (ciclopirox, ibuprofen), and for the development of the operation mode of the grinding process. We also tested different techniques such as acoustic attenuation spectroscopy and dynamic light scattering to characterize the ground particle size distribution, based on an experimental study conducted on calcite, used in this study as reference material. The second part was devoted to the milling process by grinding beads applied to the selected materials. The influence of operating parameters such as suspension flow rate, stirrer tip speed, grinding media diameter and solid mass concentration on grinding process efficiency and ground products quality were investigated. The quality criteria considered in this study are particle size distribution, stability and rheological behaviour of the products, as well as their structural properties. The effect of grinding process on the microstructural change of different materials was finally analysed. Particular attention was also focused on the effect of temperature on size reduction process and ground ibuprofen properties.

Background: Separation science is heavily reliant on materials to fulfill ever more complicated demands raised by other areas of science, notably the rapidly expanding molecular biosciences and environmental monitoring. The key to successful separations lies in a combination of physical properties and surface chemistry of stationary phases used in liquid chromatographic separation, and this thesis address both aspects of novel separation materials. Methods: The thesis accounts for several approaches taken during the course of my graduate studies, and the main approaches have been i) to test a wild-grown variety of published methods for surface treatment of fused silica capillaries, to ascertain firm attachment of polymeric monoliths to the wall of microcolumns prepared in silica conduits; ii) developing a novel porogen scheme for organic monoliths including polymeric porogens and macromonomers; iii) evaluating a mesoporous styrenic monolith for characterization of telomers intended for use in surface modification schemes and; iv) to critically assess the validity of a common shortcut used for estimating the porosity of monoliths prepared in microconduits; and finally v) employing plasma chemistry for activating and subsequently modifying the surface of rigid, monodisperse particles prepared from divinylbenzene. Results: The efforts accounted for above have resulted in i) better knowledge of the etching and functionalization parameters that determine attachment of organic monoliths prepared by radical polymerization to the surface of silica; ii) polar methacrylic monoliths with a designed macroporosity that approaches the desired "connected rod" macropore morphology; iii) estab¬lishing the usefulness of monoliths prepared via nitroxide mediated polymerization in gradient polymer elution chromatography; iv) proving that scanning electron microscopy images are of limited value for assessing the macroporous properties of organic monoliths, and that pore measurements on externally polymerized monolith cocktails do not represent the porous properties of the same cocktail polymerized in narrow confinements; and v) showing that plasma bromination can be used as an activation step for rigid divinylbenzene particles to act as grafting handles for epoxy-containing telomers, that can be attached in a sufficiently dense layer and converted into carboxylate cation exchange layer that allows protein separations in fully aqueous eluents.

Abstract : Although concrete is a relatively green material, the astronomical volume of concrete produced worldwide annually places the concrete construction sector among the noticeable contributors to the global warming. The most polluting constituent of concrete is cement due to its production process which releases, on average, 0.83 kg CO[subscript 2] per kg of cement. Self-consolidating concrete (SCC), a type of concrete that can fill in the formwork without external vibration, is a technology that can offer a solution to the sustainability issues of concrete industry. However, all of the workability requirements of SCC originate from a higher powder content (compared to conventional concrete) which can increase both the cost of construction and the environmental impact of SCC for some applications. Ecological SCC, Eco-SCC, is a recent development combing the advantages of SCC and a significantly lower powder content. The maximum powder content of this concrete, intended for building and commercial construction, is limited to 315 kg/m[superscript 3]. Nevertheless, designing Eco-SCC can be challenging since a delicate balance between different ingredients of this concrete is required to secure a satisfactory mixture. In this Ph.D. program, the principal objective is to develop a systematic design method to produce Eco-SCC. Since the particle lattice effect (PLE) is a key parameter to design stable Eco-SCC mixtures and is not well understood, in the first phase of this research, this phenomenon is studied. The focus in this phase is on the effect of particle-size distribution (PSD) on the PLE and stability of model mixtures as well as SCC. In the second phase, the design protocol is developed, and the properties of obtained Eco-SCC mixtures in both fresh and hardened states are evaluated. Since the assessment of robustness is crucial for successful production of concrete on large-scale, in the final phase of this work, the robustness of one the best-performing mixtures of Phase II is examined. It was found that increasing the volume fraction of a stable size-class results in an increase in the stability of that class, which in turn contributes to a higher PLE of the granular skeleton and better stability of the system. It was shown that a continuous PSD in which the volume fraction of each size class is larger than the consecutive coarser class can increase the PLE. Using such PSD was shown to allow for a substantial increase in the fluidity of SCC mixture without compromising the segregation resistance. An index to predict the segregation potential of a suspension of particles in a yield stress fluid was proposed. In the second phase of the dissertation, a five-step design method for Eco-SCC was established. The design protocol started with the determination of powder and water contents followed by the optimization of sand and coarse aggregate volume fractions according to an ideal PSD model (Funk and Dinger). The powder composition was optimized in the third step to minimize the water demand while securing adequate performance in the hardened state. The superplasticizer (SP) content of the mixtures was determined in next step. The last step dealt with the assessment of the global warming potential of the formulated Eco-SCC mixtures. The optimized Eco-SCC mixtures met all the requirements of self-consolidation in the fresh state. The 28-day compressive strength of such mixtures complied with the target range of 25 to 35 MPa. In addition, the mixtures showed sufficient performance in terms of drying shrinkage, electrical resistivity, and frost durability for the intended applications. The eco-performance of the developed mixtures was satisfactory as well. It was demonstrated in the last phase that the robustness of Eco-SCC is generally good with regards to water content variations and coarse aggregate characteristics alterations. Special attention must be paid to the dosage of SP during batching. / Résumé : Même si le béton est un matériau relativement vert, le volume astronomique de béton produit à travers le monde chaque année met le secteur de la construction en béton parmi les contributeurs important au réchauffement climatique. Le constituant le plus polluant du béton est le ciment en raison de son processus de production qui dégage, en moyenne, 0,83 kg de CO[indice inférieur 2] par kg de ciment. Le béton autoplaçant (BAP), un type de béton qui peut remplir le coffrage sans vibration externe, est une technologie qui peut offrir une solution aux problèmes de développement durable de l'industrie du béton. Cependant, toutes les exigences de la maniabilité du BAP proviennent d'une teneur en poudre plus élevé (par rapport au béton conventionnel), ce qui peut augmenter le coût de la construction et de l'impact environnemental du BAP pour certaines applications. Le BAP écologique, Éco-BAP, est un développement récent combinant les avantages du BAP tout en ayant une teneur en poudre significativement plus faible. La teneur en poudre maximale de ce béton, destinée à la construction du bâtiment et aux applications commerciales, est limitée à 315 kg/m[indice supérieur 3]. Néanmoins, la conception de l’Éco-BAP peut être difficile, car un équilibre délicat entre les différents ingrédients de ce béton est nécessaire pour garantir un mélange satisfaisant. Dans ce programme de doctorat, l'objectif principal est de développer une méthode systématique pour la formulation de l’Éco-BAP. Puisque l'effet de groupe des particules (EGP) est un paramètre clé pour la conception des mélanges l’Éco-BAP stables, et que ce phénomène est peu connu, dans la première phase de cette recherche, l’EGP est étudié. Cette partie se concentre sur l'influence de la granulométrie sur l’EGP et la stabilité des mélanges de modèle ainsi que des BAPs. Dans la deuxième phase, le protocole de formulation est développé, et les propriétés des mélanges obtenus, à l’état frais ainsi que l’état durcis, sont évaluées. Étant donné que l'évaluation de la robustesse est cruciale pour la production du béton à grande échelle, dans la dernière phase de ce travail, la robustesse d'un des mélanges les plus performants de la Phase II est examinée. Basé sur les résultats obtenus, nous constatons que l'augmentation de la fraction volumique d'une classe mène à une meilleure stabilité de cette classe. Cela contribue également à une EGP supérieure du squelette granulaire et à une stabilité plus élevée du système. Il a été montré qu'une granulométrie continue dans lequel la fraction volumique de chaque classe est plus grande que la classe consécutive plus grossière peut augmenter l’EGP. En utilisant une telle granulométrie, la fluidité d’un mélange du BAP pourrait être augmentée sans compromettre la résistance à la ségrégation. Un indice de prédiction du potentiel de la ségrégation de particules suspendues dans un fluide à seuil a été proposé. Dans la deuxième phase de la thèse, une méthode de conception en cinq étapes pour l’Éco-BAP a été développée. Le protocole de formulation commence par la détermination des teneurs en poudre et de l'eau, suivie par l'optimisation des fractions volumiques du sable et des gros granulats selon un modèle idéal de granulométrie (Funk et Dinger). La composition de poudre est optimisée dans la troisième étape afin de minimiser la demande en eau tout en garantissant une performance adéquate à l'état durci. Le dosage du superplastifiant (SP) est déterminé dans l’étape suivante. La dernière étape s’agit d’évaluer le potentiel du réchauffement climatique des mélanges développés. Les mélanges de l’Éco-BAP optimisés répondent à toutes les exigences à l'état frais pour le BAP. La résistance à la compression à 28 jours de ces mélanges est dans la fourchette cible de 25 à 35 MPa. En outre, les mélanges montrent des performances suffisantes en termes de retrait de séchage, la résistivité électrique, et la résistance contre gel-dégel pour les applications visées. La performance écologique des Éco-BAPs produis a été satisfaisante. Il a été démontré dans la dernière phase que la robustesse de l'Éco-BAP est généralement bonne en ce qui concerne les variations de teneur en eau et les changements de propriétés des gros granulats. Une attention particulière doit être accordée au dosage du SP pendant le malaxage.