Alkaline industrial wastes are considered potential resources for the mitigation of CO2 emissions by simultaneously capturing and sequestering CO2 through mineralization. Mineralization safely and permanently stores CO2 through its reaction with alkaline earth metals. Apart from natural formations, these elements can also be found in a variety of abundantly available industrial wastes that have high reactivity with CO2, and that are generated close to the emission point-sources. Apparently, it is the applicability and marketability of the carbonated products that define to a great extent the efficiency and viability of the particular process as a point source CO2 mitigation measure. This project investigates the valorization of iron- and steel-making slags through methods incorporating the carbonation of the material, in order to achieve the sequestration of sufficient amounts of CO2 in parallel with the formation of valuable and marketable products. Iron- and steel-manufacturing slags were selected as the most suitable industrial byproducts for the purposes of this research, due to their high production amounts and notable carbonation capacities. The same criteria (production amount and carbonation capacity) were also used for the selection of the iron- and steel-making slag types that are more suitable to the scope of this work. Specifically for the determination of the slag types with the most promising carbonation capacities, the maximum carbonation conversions resulting from recent publications related to the influence of process parameters on the conversion extent of iron- and steel-manufacturing slags, were directly compared to each other using a new index, the Carbonation Weathering Rate, which normalizes the results based on particle size and reaction duration. Among the several iron- and steel-manufacturing slags, basic oxygen furnace (BOF) and blast furnace (BF) slags were found to combine both high production volumes and significant affinity to carbonation. In the context of this research, two different procedures aiming to the formation of value added materials with satisfactory CO2 uptakes were investigated as potential BF and BOF slags valorization methods. In them, carbonation was combined either with granulation and alkali activation (BOF slag), or with hydrothermal conversion (BF slag). Both treatments seemed to be effective and returned encouraging results by managing to store sufficient amounts of CO2 and generating materials with promising qualities. In particular, the performance of the granulation-carbonation of BOF slag as a method leading to the production of secondary aggregates and the sequestration of notable amounts of CO2 in a solid and stable form, was evaluated in this work. For comparison purposes, the material was also subjected to single granulation tests under ambient conditions. In an effort to improve the mechanical properties of the finally synthesized products, apart from water, a mixture of sodium hydroxide and sodium silicate was also tested as a binding agent in both of the employed processes. According to the results, the granules produced after the alkali activation of the material were characterized by remarkably greater particle sizes (from 1 to 5 mm) compared to that of the as received material (0.2 mm), and by enhanced mechanical properties, which in some cases appeared to be adequate for their use as aggregates in construction applications. The maximum CO2 uptake was 40 g CO2/kg of slag and it was achieved after 60 minutes of the combined treatment of alkali activated BOF slag. Regarding the environmental behavior of the synthesized granules, increased levels of Cr and V leaching were noticed from the granules generated by the combination of granulation-carbonation with alkali activation. Nevertheless, the combination of granulation with alkali activation or that of granulation with carbonation were found not to worsen, if not to improve, the leaching behaviour of the granules with regards to the untreated BOF slag. The formation of a zeolitic material with notable heavy metal adsorption capacity, through the hydrothermal conversion of the solid residues resulting from the calcium- extraction stage of the indirect carbonation of BF slag, was also investigated in this project. To this end, calcium was selectively extracted from the slag by leaching, using acetic acid of specific concentration (2 M) as the extraction agent. The residual solids resulting from the filtration of the generated slurry were subsequently subjected to hydrothermal conversion in caustic solution of two different compositions (NaOH of 0.5 M and 2 M). Due to the presence of calcium acetate in the composition of the solid residues, as a result of their inadequate washing, only the hydrothermal conversion attempted using the sodium hydroxide solution of higher concentration (2 M) managed to turn the amorphous slag into a crystalline material, mainly composed by a zeolitic mineral phase (detected by XRD), namely, analcime (NaAlSi2O6·H2O), and tobermorite (Ca5(OH)2Si6O16·4H2O). Finally, the heavy metal adsorption capacity of the particular material was assessed using Ni2+ as the metal for investigation. Three different adsorption models were used for the characterization of the adsorption process, namely Langmuir, Freundlich and Temkin models. Langmuir and Temkin isotherms were found to better describe the process, compared to Freundlich model. Based on the ability of the particular material to adsorb Ni2+ as reported from batch adsorption experiments and ICP-OES analysis, and the maximum monolayer adsorption capacity (Q0 = 11.51 mg/g) as determined by the Langmuir model, the finally synthesized product can potentially be used in wastewater treatment or environmental remediation applications.

Cette thèse de doctorat est réalisée en partenariat avec EDF et s’inscrit dans le cadre de la gestion du parc de tours aéroréfrigérantes des centrales nucléaires. Certaines tours présentent des fissures qui peuvent favoriser la carbonatation du béton d’enrobage et ainsi accélérer l’initiation de la corrosion des armatures. L’objectif de ce travail est de caractériser l’impact de ces fissures sur l’initiation et la propagation de la corrosion des armatures. Un programme expérimental dédié est détaillé. Dans un premier temps, un protocole de fissuration permettant de reproduire les fissures observées sur les tours est défini. Une attention particulière a été portée à la limitation de l’endommagement de l’interface acier/béton. Les éprouvettes fissurées sont ensuite carbonatées (de manière accélérée) dans le double but de mesurer la longueur de la zone d’interface altérée et de dépassiver l’armature en fond de fissure pour permettre l’initiation de la corrosion. La corrosion est contrôlée en laboratoire par l’intermédiaire de cycles de pluie/séchage et l’état de corrosion est caractérisé par différentes techniques (desquamation, microscopie optique, spectroscopie Raman, suivi de potentiel de corrosion libre). Différentes configurations représentatives du service des tours aéroréfrigérantes sont testées (3 ouvertures de fissures, 2 orientations de fissures, température, HR, etc.). Les résultats obtenus permettent de montrer qu’après une période d’initiation, la vitesse moyenne de corrosion décroit rapidement et que l’acier tend à se repassiver. Cette repassivation est liée à la formation d’une couche d’oxydes en fond de fissure qui limite l’accès de l’oxygène et de l’eau à l’armature. / This thesis is performed in partnership with EDF in the framework of concrete ageing management of cooling towers of Electricity of France (EDF) nuclear power plants. Indeed some of them can be affected by cracks which may promote the carbonation of the concrete cover and accelerate the reinforcement corrosion initiation. The objective of this work is to characterize the impact of these cracks on the initiation and propagation of reinforcement corrosion. A dedicated experimental program is detailed. Firstly, a cracking protocol reproducing cracks found in the concrete of cooling towers is defined. Particular attention was paid to limit the damage along the steel/mortar interface. Cracked specimens are thereafter exposed to accelerated carbonation for the dual purpose of measuring the length of the damaged interface and accelerating the depassivation of the rebar deep in the crack in order to accelerate the corrosion initiation. The corrosion is controlled in the laboratory via raining/drying cycles and its state is characterized by several technics (desquamation, optical microscopy, Raman spectroscopy, monitoring of the free corrosion potential). Different configurations representative of the cooling towers are tested (three crack openings, 2 crack orientations, temperature, relative humidity, etc.). Obtained results show that after the corrosion initiation period, the corrosion kinetics decreases rapidly and the reinforcement tends to repassivation. This repassivation is related to the formation of oxide layer deep in the crack limiting therefore the access of water and oxygen to the rebar.

Lime has been used in construction for millennia, and its value, especially in the field of conservation architecture, has only recently been rediscovered. Lime mortars harden through carbonation, and this thesis is a study of that process. The research conducted has resulted in the development of two novel techniques for the measurement and detection of carbonation. The first technique is a method of thermogravimetric analysis which allows the carbonation profile to be measured within an acceptable time-frame. The second technique is the use of drilling resistance measurement to visualise the carbonation profile. The potential of elemental analysis to measure the carbonation profile has also been identified. It has been demonstrated that the lime/water ratio has less impact on the compressive strength of air lime mortars than had previously been supposed. The change in the pore size distribution of air lime mortars caused by carbonation has been studied, and a theory has been proposed to explain this phenomenon. Five different forms of air lime binder were studied. The impact of these on the structural performance of the resultant mortars has been assessed. It was concluded that mortars made with lime putties perform better than mortars made with dry lime hydrate. Mortars made with dispersed hydrated lime appear to perform as well as mortars made with lime putties, but at a slower rate of strength growth. The use of extra mature lime putty does not appear to confer structural performance benefits when compared with ordinary lime putty. It has been shown that the use of calcitic aggregates can produce air lime mortars which perform as well as moderately hydraulic lime mortars. It is theorised that this phenomenon is not directly related to carbonation, but rather to a complex interaction of the granulometry, mineralogy, chemistry and porosity of the aggregate with the binder.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-06-30T19:06:20Z No. of bitstreams: 1 Bruno Rommel Cattani Sartori.pdf: 2512461 bytes, checksum: abb3f86120ab4514cee67cbf57c00264 (MD5) / Made available in DSpace on 2015-06-30T19:06:20Z (GMT). No. of bitstreams: 1 Bruno Rommel Cattani Sartori.pdf: 2512461 bytes, checksum: abb3f86120ab4514cee67cbf57c00264 (MD5) Previous issue date: 2013-08-16 / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul / Milton Valente / Este trabalho tem por finalidade contribuir para os estudos de durabilidade de concretos com a inserção de agregados graúdos reciclados de concreto (AGRC) e de cinza de casca de arroz (CCA) em concretos frente à carbonatação. Trabalhando com a hipótese de que o emprego de CCA possa mitigar o efeito da alta porosidade do AGRC nas propriedades do concreto, foram produzidos concretos com 0, 25 e 50% de AGRC; 0, 10 e 20% de CCA e relações água/aglomerante iguais a 0,42, 0,53 e 0,64. Para o ensaio de carbonatação acelerada, utilizou-se uma câmara de carbonatação com alimentação contínua de solução gasosa a 3% de CO2 e umidade relativa controlada, na qual os concretos permaneceram durante 63 dias. Os resultados apontaram para um efeito positivo do emprego de CCA nos concretos produzidos com AGRC. A substituição de cimento por CCA em média pode aumentar a resistência à compressão e à tração. Os concretos com relação a/agl 0,42, para a grande parte dos concretos ensaiados, retornaram resistências à compressão de 40 MPa à 55 MPa, com coeficiente de carbonatação de 1,0mm/dia½ a 1,5 mm/dia½, independente do teor de CCA. No entanto, concretos com relação a/agl mais alta (0,64), apresentaram resistência entre 15 MPa e 30 MPa, sendo que para grande parte destes o coeficiente de carbonatação se apresenta na faixa abaixo dos 3,0 mm/dia½ e acima do 2,0 mm/dia½. / This research contributes to the study of concrete carbonation using recycled concrete coarse aggregates (RCA) and rice husk ash (RHA). The use of RHA may contribute to reduce the effects of RCA's high porosity on the properties of the concrete. It was used 0,25 and 50% of RCA in replacement of natural aggregate; 0,10 and 20% of RHA as cement replacement; and water/binder 0.42, 0.53 and 0.64. For the accelerated carbonation test it was used a carbonation chamber with continuous feeding gaseous solution at 3% CO2 and controled relative humidity, where the concrete samples remained for 63 days. The results point to a positive effect of the use of RHA in concrete produced with RCA. Concretes with water/binder 0.42, for the most of the concrete tested, resulted in a compressive strength of 40 MPa to 55 MPa, with carbonation coefficient of 1.0mm/day1/2 to 1.5 mm/day1/2, independent of the amount of the RHA. However, concretes with higher water/binder (0.64) showed resistance between 15 MPa and 30 MPa, and for most of these the carbonation coefficient is below 3.0 mm/day1/2 and above 2.0 mm/day1/2.

Le procédé Solvay génère d’énormes quantités de saumures résiduaires au pH alcalin contenant portlandite, brucite et silicates de calcium hydratés. La carbonatation conduit à un abaissement du pH, ce qui favorise la formation de deux phases majoritaires : la calcite et le gypse. L’objectif de la thèse est de valoriser les saumures résiduaires carbonatées par séparation des phases en colonne de flottation. L’étude de la carbonatation en réacteur batch, puis en colonne de carbonatation pilote montre qu’il est préférable de ne pas carbonater les saumures résiduaires jusqu’à l’équilibre thermodynamique. En effet, la mise en solution de métaux lourds intervient à partir d’un pH de l’ordre de 7,5, ce qui limiterait les rejets des saumures dans l’environnement. En outre, une carbonatation brusque et incomplète est souhaitable pour une meilleure séparation des phases par flottation. Les essais de flottation réalisés sur une colonne de 7,6 cm de diamètre et de 3 m de haut ont montré une faisabilité de la séparation des deux minéraux calciques avec l’oléate de sodium comme collecteur malgré une abondante littérature incitant à la prudence. La différence entre la taille des particules de carbonates et celle des particules de sulfates et leurs hydratations de surfaces, ainsi qu’une force ionique élevée du milieu permettent une bonne séparation des phases. Une étude des saumures synthétiques permet de mettre en évidence le rôle des cations métalliques (nature, rayon, charge…) sur la coalescence des bulles dans les conditions dynamiques et dans un milieu à forte force ionique. Une étude des paramètre de fonctionnement effectué sur une colonne de 30,5 cm de diamètre et de 10 m de haut ont permis la modélisation du procédé de flottation en colonne dans le but de proposer une procédure de dimensionnement du procédé industriel. La confrontation des résultats de simulation aux résultats réels permet la détermination des intensités des microprocessus de flottation (attachement/détachement), et conduit à la proposition d’une installation industrielle avec deux colonnes de flottation en série / Solvay process generates huge amounts of waste brines at alkaline pH containing portlandite, brucite and calcium silicate hydrates. Carbonation leads to lowering of pH which favors formation of two predominant phases: calcite and gypsum. The aim of this thesis is to develop carbonated waste brines valorization by phase separation in flotation column Study of carbonation in a batch reactor and in a carbonation pilot column shows it is preferable not to carbonate waste brines until thermodynamic equilibrium. Indeed dissolution of heavy metals occurs from a pH of about 7.5 thereby limiting discharge of brines in the environment. In addition, a sudden and incomplete carbonation is appropriate for phase separation by flotation. Flotation tests carried out in a 7.6 cm diameter and 3 m high column showed feasibility of the separation of the two calcium minerals using sodium oleate as a collector despite abundant literature for caution. The differences between the particle size of carbonates and sulfates and their surface hydration, as well as the high ionic strength of the medium allow an efficient separation of phases. Study of synthetic brines highlights the role of metal cations (nature, radius, charge…) on bubble coalescence in dynamic conditions in an environment with high ionic strength. Study of operation parameter performed on a 30.5 cm diameter and 10 m high column enabled the modeling of the column flotation process in order to provide a scale-up procedure of industrial process. Comparison of simulation results with actual results allows the determination of intensities of flotation subprocesses (attachment/detachment), and led to the proposal of an industrial plant with two flotation columns in series

O uso de fibras vegetais e de cimentos alternativos – ambos provenientes de resíduos, é tido como boa opção na busca por novos fibrocimentos. Entretanto, a maioria das pesquisas desenvolvida nos últimos anos tem apresentado resultados desanimadores no que se refere à durabilidade do material. Além disso, os métodos para avaliação do desempenho ao longo do tempo de materiais reforçados com fibras sensíveis a álcalis ainda não estão bem estabelecidos. O trabalho avaliou o comportamento de compósitos produzidos com cimento de escória de alto-forno reforçados com fibras de celulose, moldados através de adaptações dos processos industriais usados em todo mundo pelas empresas de fibrocimento. Em seguida, a durabilidade das formulações foi avaliada através de ensaios de envelhecimento, os quais se basearam na simulação dos principais agentes e mecanismos de degradação atuantes no material. O desempenho físico e mecânico dos compósitos foi avaliado através da análise de propriedades pré-estabelecidas, consideradas importantes no emprego material como componente construtivo. A análise dos resultados confirmou a eficiência da incorporação da celulose nas propriedades mecânicas do compósito. A durabilidade do material foi diferente para as matrizes empregadas. As matrizes ativadas com gipsita e cal hidratada (EGCH) foram menos agressivas às fibras, entretanto apresentaram problemas de hidratação às primeiras idades e perda de resistência devido à carbonatação. A matriz ECP, mais alcalina, apresentou resultados superiores de resistência mecânica nas primeiras idades. Ela decompôs as fibras e reduziu as propriedades mecânicas durante o envelhecimento. A carbonatação reduziu o ataque alcalino às fibras nestas matrizes, estabilizando a resistência mecânica e a perda de tenacidade não foi tão acentuada. A metodologia de envelhecimento acelerado que combinou ciclos de molhagem e secagem à carbonatação se mostrou eficiente na simulação do envelhecimento natural. / Vegetable fibers and alternative cements from residues is a good option for replacement asbestos-cement. However, research development has presented no satisfactory results concerning material durability and methods of performance evaluation to reinforced materials with alcali sensitive fibers are not well developed. The objetives of this research are: a) evaluation of composites behavior produced with blast-furnace slag reinforced with residual cellulose fibers, which were moulded in adapted conventional industrial processes, common in fibercement companies around world and b) durability performance evaluation applying proposed aging tests. Aging tests were based on simulation of main agents and degradation mechanisms. Physical and mechanical behaviour of composites was evaluated considering important properties in building component uses. Cellulose fibers improved the mechanical properties of the composites. Durability presented different results for the two matrices. The matrices activated with gypsum and hidrated lime (EGCH) have been less aggressive than matrix activated with ordinary Portland cement (OPC) in relation to fibers. However, they presented problems concerning to the hydration at early dates and loss of resistance due to carbonation. Matrices activated with OPC presented better results of MOR at the early dates. In fact, they are more alkaline and they decomposed fibers and reduced the mechanical properties during the aging. The carbonation reduced the alkaline attack, stabilizing the MOR and reducing the loss of tenacity. The accelerated methods with carbonation were efficient in the simulation of the natural ageing.

O regolito é o manto do intemperismo existente sobre as rochas. Este manto pode ser constituído estruturalmente por três entidades distintas denominadas, solo, sedimento e saprolito. Ambas são produtos da intemperização das rochas. No entanto, o saprolito é definido como o único produto não transportado da intemperização isovolumétrica do litotipo originário. Diferente dos solos, dos sedimentos ou das rochas, não existe uma ciência específica para o estudo dos saprolitos. A saprolitologia não existe oficialmente, porém, pode ser implicitamente encontrada em trabalhos científicos de todo o mundo. No primeiro capítulo da tese, apresenta-se o estado da arte dos estudos dos saprolitos e sugere-se a consolidação da saprolitologia com o intuito de incentivar o incremento das pesquisas voltadas a esta entidade ainda pouco conhecida. De fato, os processos relacionados à intemperização isovolumétrica das rochas ainda não foram completamente compreendidos. Neste contexto, o Estado de Pernambuco, no nordeste do Brasil, apresenta condições geomorfológicas e climáticas propícias ao estudo da formação de saprolitos. No segundo capítulo da tese, demonstra-se que o intemperismo isovolumétrico de treze rochas cristalinas foi mais influenciado pelas condições microambientais, a exemplo da dinâmica da água através da microestrutura, do que pelas condições macroambientais. Posteriormente ao intemperismo isovolumétrico, diferenças morfológicas e geoquímicas ocorrem durante a evolução vertical do regolito. Entretanto, os domínios da saprolitogênese e da pedogênese são difíceis de diferenciar. No terceiro capítulo da tese, avaliou-se a evolução morfológica, estrutural e geoquímica de treze perfis formados por sistemas solo-saprolitos derivados do embasamento cristalino do Estado de Pernambuco. Anomalias nos índices de mensuração do intemperismo demonstram que o aumento gradual do grau de intemperização dos horizontes mais superficiais em relação aos horizontes inferiores não é a regra durante a evolução vertical do regolito. Em adição, a geoquímica e a morfologia dos perfis estudados indicam que alguns sistemas solo-saprolitos desenvolveram-se de forma interligada e outros apresentam evidências de que a formação do saprolito pode ter ocorrido após a formação do solo sobrejacente. Durante a evolução do regolito, o solo e o saprolito influenciam processos essenciais ao meio ambiente. No quarto capítulo da tese, descrevem-se as implicações agrícolas e ambientais dos treze perfis descritos no terceiro capítulo. Os resultados sugerem que os processos geoquímicos existentes nos sistemas solo-saprolitos, a exemplo da \"mineral carbonation\", influenciam o fluxo de elementos através do ecossistema circundante e demonstram que os saprolitos possuem importância agrícola e ambiental análoga à dos solos, influenciando processos de relevância agroambientais tais como a dinâmica da água, a retenção e transporte de nutrientes e/ou a retenção e transporte de contaminantes ou poluentes. / The regolith is the mantle of weathering above the rocks. This mantle may consist of three structurally distinct entities denominated sediment, soil and saprolite. All are products of rock weathering. Saprolite is defined as the product of in situ, isovolumetric weathering of the lithotype. Unlike the soils, sediments or rocks, there is no specific science dedicated to the study of saprolite. The saprolihtology does not exist formally. However, it can implicitly be found in scientific papers from around the world. The first chapter of the thesis presents the state of the art of saprolite studies and suggests the consolidation of saprolithology in order to encourage the development of research focused in this entity poorly known. In fact, the processes related to the isovolumetric weathering of rocks are not yet fully understood. In this context, the Pernambuco State in Northeastern Brazil have geomorphological and climatic conditions prone to the study of the saprolite formation and evolution. The second chapter of this thesis demonstrates that the isovolumetric weathering of the thirteen crystalline rocks was more influenced by microenvironmental conditions, such as the water dynamics through the microstructure, than the macro-environmental conditions. Subsequent to isovolumetric weathering, morphological and geochemical differenciation occur during the vertical evolution of regolith. However, it is difficult to differentiate the domains of saprolithogenesis and pedogenesis. The third chapter of the thesis reports the morphological, structural and geochemical evolution of the thirteen profiles formed by soil-saprolite systems derived from the crystalline basement of the Pernambuco State. Anomalies in the weathering measurement indexes showed that the gradual increase in the degree of weathering from the surface horizons towards the subsurface horizons is not the rule for the vertical development of regolito. In addition, the geochemistry and the morphology of the studied profiles indicate that some soil-saprolite systems evolved in an interconnected way and others provide evidence that the formation of saprolite may have occurred after the formation of the overlying soil. During the regolith evolution, soil and saprolite influence key environmental processes. The fourth chapter describes the agricultural and environmental implications of the processes acting in the thirteen profiles described in the third chapter. The results suggest that existing processes in geochemical soil-saprolite systems, such as the mineral carbonation, have influenced the elements flow through the surrounding ecosystem and demonstrate that saprolites have agricultural and environmental importance analogous to soil, influencing processes such as water fluxes, retention and transport of nutrients and/or of contaminants or pollutants.

L'entreprise Juxta produit des résines pour des revêtements transparents de fortes épaisseurs en polyuréthane. Ces revêtements sont fabriqués à partir de deux produits dangereux : les isocyanates et un catalyseur à base de mercure. Pour protéger ses employés et consommateurs, l'entreprise Juxta a lancé un projet de substitution des isocyanates dans les polyuréthanes. Pour ce faire, trois nouvelles voies de synthèse ont été envisagées :La voie cyclocarbonate/amine est la plus novatrice. Dans un premier temps, la réactivité de cyclocarbonates et d'amines modèles a été étudiée ainsi que l'effet de différents catalyseurs. Les meilleurs catalyseurs sont de la famille des thiourées, urées et guanidines. Puis une voie d'accès à des cyclocarbonates incolores a été mise au point. Enfin, une étude a permis de mettre en évidence que les liaisons hydrogènes étaient responsables du faible avancement de la réaction lors de la synthèse de polyhydroxyuréthanes linéaires.La voie époxy/amine a permis de développer une gamme de matériaux transparents avec des Tg allant de 18 à 47°C. Une étude IR a été réalisée, permettant de mieux appréhender le phénomène de carbonatation de l'amine, récurent lors de la synthèse de résines époxys à température ambiante. L'utilisation de prépolymères aminotéléchéliques permet de contourner ce phénomène.La voie acrylate/amine a permis de développer un matériau transparent de basse Tg, -12°C. L'étude de la réactivité des acrylates avec les amines a été réalisée par DSC et RMN. Des tests de formulation ont été effectués dans le but d'augmenter la Tg / Juxta company produces thick transparent polyurethane coatings. These coatings are made from hazardous compounds, isocyanates and a mercury based catalyst. In order to protect its employees and consumers Juxta company wants to get rid of the isocyanates in its formulations. Therefore, three new synthesis pathways have been considered.The carbonate/amine pathway is the more innovative one. First, the reactivity and catalysis of model cyclocarbonates and amines were studied. The thioureas, ureas and guanidines proved to be very efficient catalyst families for the cyclocarbonate aminolysis. Then a synthesis was developed to obtain transparent cyclocarbonates. To conclude, a study conducted on linear polyurethanes demonstrated that hydrogen bondings are responsible for the low conversions observed with this reaction.Transparent materials with Tg ranging from 18°C to 47°C were synthesized using the epoxy/amine pathway. An IR study was performed to better understand the amine carbonation phenomenon. It is a frequent phenomenon when the epoxy resins are synthesized at room temperature. Aminotelechelic prepolymers can be used to circumvent it.A low Tg (-12°C) transparent material was synthesized using acrylate/amine synthesis. The couple reactivity was studied by DSC and NMR. Then several formulations were performed in order to increase the Tg

In this research, two phases of work were conducted. First, an investigation into the durability concerns for precast prestressed concrete piles exposed to marine environments was conducted. The investigation characterized the durability concerns of chemical, biological, and physical deterioration mechanisms. The results of this study were used to develop potential high performance marine concretes (HPMC) that would be capable of 100+ year service lives in marine environments. Extensive durability testing and service life modeling of the HPMC was performed. Chloride ingress resistance was investigated using accelerated and long-term test procedures and the results used to perform service life modeling to predict the time before corrosion initiation. Sulfate resistance characterization was performed using multiple techniques to characterize the physical and chemical behavior of binder compositions containing binary or ternary mixes containing cement and supplementary cementitious materials (SCM's) subjected to a sulfate-laden environment. Accelerated carbonation testing and material characterization led to the finding of relationships in the chemical composition of mix designs and the observed durability and the results used to perform corrosion initiation service life modeling. An investigation into the influence of self-healing of cracked concrete led to fundamental findings on the behavior of chloride ingress for cracked concrete structures in marine environments. The results of this research led to the development of concrete mix designs capable of providing service lives over 100 years in Georgia's marine environments, as well as the advancement of the current state of knowledge on the durability characteristics of ternary mix designs.

Made available in DSpace on 2014-12-17T14:07:10Z (GMT). No. of bitstreams: 1 CarinaGMMB_TESE.pdf: 4060316 bytes, checksum: 4ffd1d674b7bda144d5cd732432d8bfb (MD5) Previous issue date: 2012-12-14 / One of the major challenges faced nowadays by oil companies is the exploration of pre-salt basins. Thick salt layers were formed in remote ages as a consequence of the evaporation of sea water containing high concentrations of NaCl and KCl. Deep reservoirs can be found below salt formations that prevent the outflow of oil, thus improving the success in oil prospection. The slurries used in the cement operations of salt layers must be adequate to the properties of those specific formations. At the same time, their resulting properties are highly affected by the contamination of salt in the fresh state. It is t herefore important to address the effects of the presence of salt in the cement slurries in order to assure that the well sheath is able to fulfill its main role to provide zonal isolation and mechanical stability. In this scenario, the objective of the present thesis work was to evaluate the effect of the presence of NaCl and KCl premixed with cement and 40% silica flour on the behavior of cement slurries. Their effect in the presence of CO2 was also investigated. The rheological behavior of slurries containing NaCl and KCl was evaluated along with their mechanical strength. Thermal and microstructural tests were also carried out. The results revealed that the presence of NaCl and KCl affected the pozzolanic activity of silica flour, reducing the strength of the hardened slurries containing salt. Friedel?s salt was formed as a result of the bonding between free Cl- and tricalcium aluminate. The presence of CO2 also contributed to the degradation of the slurries as a result of a process of carbonation/bicarbonataion / Atualmente, um dos grandes desafios para as empresas petrol?feras ? a explora??o de petr?leo em bacias dominadas por estruturas salinas, mais conhecidas por zonas evapor?ticas. A camada de sal ? formada pela evapora??o da ?gua do mar, cuja composi??o qu?mica inclui altas concentra??es de cloreto de s?dio (NaCl). Reservat?rios profundos s?o encontrados abaixo de espessas camadas de sal que vedam o fluxo de ?leo para fora da rocha, aprisionando hidrocarbonetos e aumentando, assim, a probabilidade de sucesso na prospec??o de ?leo e g?s. Atendendo ?s condi??es de po?o, s?o utilizadas pastas de cimento do tipo Portland para isolar, promover resist?ncia mec?nica ao po?o e impedir a intercomunica??o zonal das forma??es rochosas produtoras. Deste modo, as pastas de cimento devem atender ? natureza dos sais, pois estes se encontram na natureza com distintas caracter?sticas. Assim, este trabalho teve como objetivo avaliar o comportamento da adi??o de sais NaCl e KCl em sistemas de pastas de cimento contendo 40% de s?lica flour e avaliar o comportamento dessas pastas frente a presen?a de CO2. As propriedades foram avaliadas atrav?s de ensaios de reologia, resist?ncia ? compress?o pelo m?todo ultrass?nico (UCA) e resist?ncia mec?nica pelo m?todo destrutivo, bem como com o uso de t?cnicas de caracteriza??o t?rmica (TG/DTG), difra??o de raios X (DRX), microscopia eletr?nica de varredura (MEV) e an?lise de EDS em microanalisadores de sonda eletr?nica (EPMA). Os resultados mostraram que a presen?a do NaCl e KCl, interferem na atividade pozol?nica da s?lica, reduzindo a resist?ncia das pastas quando adicionado altas concentra??es dos sais. Essa interfer?ncia foi comprovada devido a forma??o do sal de Friedel, resultado da liga??o dos cloretos livres ao aluminato tric?lcico, incorporado ?s fases s?lidas do cimento hidratado. Para o estudo da influ?ncia de meios ricos em CO2 em pastas de cimento, foi observada a degrada??o das pastas atrav?s do processo de carbonata??o seguido da bicarbonata??o, resultando na perda da resist?ncia mec?nica