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Les ouvrages d’assainissement en maçonnerie de meulière construits au 19ème siècle à Paris ont une forme ovoïdale et sont soumis à des sollicitations agressives qui ont largement augmenté depuis le début du 20ème siècle. Si la majorité de ces ouvrages continuent à fonctionner, leur état général se dégrade inexorablement. Comme la reconstruction n’est pas toujours possible pour des raisons de coût et d’impact social, la réhabilitation est la solution adoptée par de nombreux maîtres d’ouvrages. La thèse est une partie du projet RESAME qui a pour but de réduire les coûts de réhabilitation, d’améliorer la durabilité des réparations et de diminuer le temps d’intervention sur le site. L’objectif principal de la thèse est de mettre au point de nouvelles méthodes de restructuration plus économiques que les méthodes usuellement utilisées. Après avoir présenté les ouvrages d’assainissement et leurs types de dégradations. Les techniques d’auscultation et de réhabilitation sont données. Une synthèse bibliographique de l’application des matériaux composites sur des structures en maçonnerie est détaillée en première partie. Du fait de la géométrie et des matériaux, des voutes ont été substitué aux ovoïdes pour nos essais présentés en seconde partie. Deux procédés ont été mis au point au cours de la thèse : un chemisage mince par mortier fibré de 3 cm et un renforcement par collage de matériaux composites (Lamelles et tissus). Vingt voûtes ont subi un chargement jusqu’à la rupture. Le but de l’ensemble des essais est de déterminer les mécanismes de ruine, les charges de la première fissuration et les charges à la rupture. Un gain important est alors constaté pour les méthodes de renforcement. Les résultats obtenus sont présentés et discutés. / In 19th century, Sewerage systems constructed in Paris were egg-shaped and made of masonry. Collectors are subjected to aggressive loads which have largely increased since the early 20th century. Even, if the majority of structures are still in service, their general condition deteriorates inexorably, and as the reconstruction is not always possible for reasons of cost and social impact, rehabilitation is the solution adopted by many clients. The thesis is a part of the project RESAME designed to reduce rehabilitation costs, improve the durability of repairs and reduce response times on the site. The main objective of this thesis is to develop new methods of restructuring. After introducing sewerage systems and their types of damage, auscultation techniques and rehabilitation will be presented. A bibliographical survey of the application of composite materials on planes and curved structures masonry is detailed in first time. Because of the complexity of geometry and materials, the vaults were substituted by the ovoid for our tests presented in the second half. Two methods are developed in this thesis: a thin layer of fiber reinforced mortar (FRM) by 3 cm and reinforcement by composite materials. Twenty vaults have been loading up to failure. The purpose of the tests is to determine the failure mechanisms, the first cracking loads and breaking loads. An important gain is then observed as well as a delay in cracking for every reinforcement method. The results are presented and discussed. These two processes will be applicable on several projects soon.

L’objectif de cette thèse est d’explorer de nouvelles technologies permettant de faciliter l’intégration des isolateurs dans les chaînes radiofréquences de satellites. Ces composants sont utilisés pour contrôler l’adaptation des amplificateurs dans les sections d’entrée et de sortie des équipements RF bas niveaux. Nous proposons deux voies de réalisation de ces isolateurs. Une première voie basée sur l’utilisation de matériaux ferricomposites est étudiée pour concevoir des composants en bande Ku. Une deuxième voie, basée sur l’utilisation d’hexaferrites de strontium et de baryum préorientés, a été étudiée pour concevoir des composants auto-polarisés (sans aimants) en bandes Q et Ka. / The goal of this PhD thesis is to explore new technologies that make possible to improve the integration of isolators in radiofrequency chain of satellites. These components are especially used to control matching of amplifiers.We propose two ways of producing these isolators. At first, ferricomposite materials are studied to design low-cost isolators at Kuband.Then, we studied pre-oriented strontium or barium hexaferrites to design self-biased components (without magnets) for Q and Ka band frequencies.

[pt] Nesta dissertação foram desenvolvidos elementos estruturais passíveis de industrialização, utilizando o bambu como matéria prima principal, dando prosseguimento às pesquisas desenvolvidas pelo grupo de Materiais e Tecnologias Não Convencionais nesta Instituição, desde o final da década de 1970. Foram elaborados nós em bambu laminado contraplacado e ponteiras em material compósito polimérico, manufaturado com resíduo particulado proveniente da laminação do bambu Dendrocalamus giganteus. Foram ainda estudados colmos da espécie Phyllostachys aurea reforçados por toda a sua extensão com sisal trefilado embebido em poliéster. Estes componentes são destinados fundamentalmente à construção de treliças espaciais, retilíneas ou arqueadas, do tipo grelha em múltiplas camadas, aliando sustentabilidade e variabilidade formal para projetos de coberturas. Mediante pequenas adaptações, estes elementos podem ainda encontrar uso em outros tipos de estrutura como domos geodésicos, tensegritys e treliças planas, de caráter temporário ou permanente. A partir da análise experimental de materiais e componentes e de dados obtidos em literatura específica estudaram-se, os esforços solicitantes e deslocamentos desenvolvidos em diferentes geometrias de estruturas, via modelagem em programa comercial de elementos finitos, obtendo-se vãos livres de até 12m e áreas cobertas sobre 4 apoios com capitéis de até 324 metros quadrados com vão livre de 9m e balanços de 4,5m, elaboradas utilizando estes elementos. Os procedimentos desenvolvidos foram satisfatórios, permitindo a execução de elementos passíveis de industrialização e estocagem, de aplicação versátil e com acabamento variado, favorecendo a convencionalização do uso do bambu como material de construção. / [en] The research on non conventional materials and technologies has been carried out at the Civil Engineering Department of PUC-Rio since 1979, in order to stimulate its use in civil construction, reducing the pollution and the energy consumption provoked by industrialized materials such as steel and cement. To disseminate the application of the non-conventional materials and technologies (NOCMAT) in a very large scale, it is necessary to develop industrial methods to process them, ensuring high production with quality and durability. As a continuation of this line of research, the present study is concerned with the development of structural elements designed for space structures, using bamboo as the main material. For this purpose the bamboo Dendrocalamus giganteus, has been selected to prepare laminated composite for the joints. In turn, using its plaining residuals as an addition to a polyester matrix composite. This was molded as a conical capped connection designed and produced to provide safe links between the joints and the bar of the space truss elements. For the latter the Phyllostachys aurea bamboo transversally reinforced with a polyester treated sisal string along its entire length. These components were used to assemble plain or arched multiple layers space structures, binding sustainability and formal freedom to roof structures design. The load-displacement for different structural geometries were evaluated, using a commercial FEM software, based on the experimental data from this work and the available literature, presented 12m maximum free spans and 324 square meters covered area supported by four columns. The developed procedures were satisfactory, allowing the production of industrial processed elements, easy storage, different finishing and versatile application.

Depuis les débuts de l’aéronautique, le feu fut l’un des premiers risques identifiés. Cependant, ce dernier est encore aujourd’hui la source d’accidents, souvent fatals, faute d’issue lorsqu’il intervient en vol. Dans le même temps, le besoin de réduire la masse des aéronefs actuels, pour limiter les coûts de fonctionnement, a rendu l’utilisation des matériaux composites, particulièrement réactifs au feu, indispensables. Afin de valider la performance au feu de ces matériaux, il est donc nécessaire de certifier leurs performances lorsqu’ils sont soumis au feu. Or ces essais représentent un coût non-négligeable pendant les phases de développement. L’utilisation des simulations numériques semble donc être une bonne alternative afin de limiter le nombre d’essais. Néanmoins ces dernières nécessitent un certain nombre de paramètres d’entrée et une bonne connaissance des phénomènes de dégradation. Ainsi dans ce travail, la dégradation thermique de deux matériaux composite est étudiée, le thermoplastique carbone-PEKK et le thermodurcissable carbone-phénolique. Les propriétés thermiques et cinétiques, indispensables pour la modélisation numérique du comportement au feu des matériaux, sont dans un premier temps caractérisées à petite échelle (ATG/DSC, DIL, diffusivité par méthode flash). Par la suite, ces propriétés sont utilisées dans le modèle de pyrolyse qui est validé à moyenne échelle, à l’aide de mesures de dégradation au cône calorimètre. Enfin, des essais de résistance au feu sont réalisés afin de valider les simulations numériques à grande échelle à l’aide du brûleur NexGen de la plateforme expérimental feux VESTA. De plus, les produits de pyrolyse sont évalués au cours de la dégradation (Py-GC-MS) pour déterminer les limites inférieures d’inflammabilité en fonction de la température et ainsi proposer une classification des matériaux étudiés. / Since the beginning of aeronautics, fire has been one of the first identified risks. However, the latter is still today the source of accidents, often fatal, lack of outcome when it intervenes in flight. At the same time, the need to reduce the mass of current aircraft, to limit operating costs, has made the use of composite materials, particularly fire-resistant, essential. In order to validate the fire performance of these materials, it is therefore necessary to certify their performance when subjected to fire. These tests represent a non-negligible cost during the development phases. The use of numerical simulations seems to be a good alternative in order to limit the number of trials. Nevertheless, the latter require a certain number of input parameters and a good knowledge of degradation phenomena. Thus in this work, the thermal degradation of two composite materials is studied, the thermoplastic carbon-PEKK and the thermosetting carbon-phenolic. The thermal and kinetic properties are first characterized on a small scale (ATG / DSC, DIL, diffusivity by flash method). Subsequently, these properties are used in the pyrolysis model that is validated on a medium scale using calorimeter cone degradation measurements. Finally, fire resistance tests are carried out using the NexGen burner of the experimental VESTA fire platform. In addition, the pyrolysis products are then evaluated during the degradation (Py-GC-MS) to determine the lower flammability limits and thus propose a classification of the materials studied.

Depuis une dizaine d’années, les matériaux composites sont de plus en plus utilisés dans de nombreuses applications, et en particulier dans l'aéronautique grâce à leurs excellentes propriétés mécaniques et leur faible densité. Ainsi les derniers modèles d'Airbus (A350) et de Boeing (B787) utilisent plus de 50% en masse de composites, principalement des polymères renforcés de fibres de carbone (CFRP). Toutefois, l'augmentation de l'utilisation des CFRP soulève des préoccupations environnementales quant à leur fin de vie à travers l'élimination des déchets, la consommation de ressources non renouvelables ainsi que la nécessité de recycler les déchets CFRP. Dans ces travaux de thèse, un modèle générique est développé afin de proposer une gestion optimale des déchets de CFRP aéronautiques en prenant en compte simultanément des objectifs économiques et environnementaux. Ainsi, dans un premier temps une approche systémique suivant les lignes directrices d’une approche par Analyse de Cycle de Vie est effectuée afin de modéliser les impacts environnementaux des procédés de recyclage des CFRP, avec une attention toute particulière sur l’impact de réchauffement climatique. Ensuite, toute la chaîne logistique du recyclage des déchets CFRP est modélisée en partant des sites de démantèlement des avions jusqu’à la réutilisation des fibres recyclées vers d’autres applications possibles. Une stratégie d’optimisation multi-objectif de programmation mathématique, d’-contrainte et de technique lexicographique est développé mettent également en jeu des techniques d’aide à la décision appropriées (M-TOPSIS, PROMETHEE-GAIA). Différentes configurations de chaînes logistiques de déchet CFRP sont ainsi proposées et plusieurs scénarios sont étudiés et optimisés de façon à prendre en compte les sites de recyclage déjà existants dans une vision mono-période ainsi que déploiement de nouveaux sites selon une approche multipériode. Le cas de la France sert d’illustration à la démarche et les configurations proposées pour implanter de nouveaux sites de façon optimale traitant une fibre recyclée facilement valorisable pour des applications ciblées sont analysées et discutées minimisant le coût ou maximisant le profit pour un critère économique et minimisant un critère environnemental basé sur le potentiel de réchauffement climatique. / Composites have been increasingly used in different applications in the last decade, especially in aerospace due to their high strength and lightweight characteristics. Indeed, the latest models of Airbus (A350) and Boeing (B787) have employed more than 50 wt% of composites, mainly Carbon Fibre Reinforced Polymers (CFRP). Yet, the increased use of CFRP has raised the environmental concerns about their end-of-life related to waste disposal, consumption of non-renewable resources for manufacturing and the need to recycle CFRP wastes. In this study, a generic model is developed in order to propose an optimal management of aerospace CFRP wastes taking into account economic and environmental objectives. Firstly, a life-cycle systemic approach is used to model the environmental impacts of CFRP recycling processes focusing on Global Warming Potential (GWP) following the guidelines of Life Cycle Assessment (LCA). The whole supply chain for recycling CFRP pathways is then modelled from aircraft dismantling sites to the reuse of recycled fibres in various applications. A multi-objective optimisation strategy based on mathematical programming, -constraint and lexicographic methods with appropriate decisionmaking techniques (M-TOPSIS, PROMETHEE-GAIA) has been developed to determine CFRP waste supply chain configurations. Various scenarios have been studied in order to take account the potential of existing recycling sites in a mono-period visions as well as the deployment of new sites in a multi-period approach considering the case study of France for illustration purpose. The solutions obtained from optimisation process allow developing optimal strategies for the implementation of CFRP recovery with recycled fibres (of acceptable quality) for the targeted substitution use while minimising cost /maximising profit for an economic criterion and minimising an environmental impact based on GWP.

Made available in DSpace on 2014-12-17T14:57:51Z (GMT). No. of bitstreams: 1 ElmoTLCF_TESE.pdf: 5043931 bytes, checksum: 055ef9454dc04669cebfe47f8a31509b (MD5) Previous issue date: 2011-07-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The process of recycling has been stimulated by the markets for several reasons, mainly on economical and environmental. Several products have been developed from recycled materials that already exist as well as several residues have been studied in different forms of applications. The greater majority of the applications for thermal insulation in the domestic, commercial and industrial systems have been elaborated in the temperature ranges between low to medium reaching up to 180oC. Many materials such as glass wool, rock wool, polystyrene are being used which are aggressive to the environment. Such materials in spite of the effectiveness in the retention of heat flow, they cost more and when discarded take several years to be absorbed by the nature. This way, in order to adapt to a world politics concerning the preservation of the environment, the present study was intended to develop a material composed of natural/biodegradable materials and industrial residues. The development of such a product in the form of a composite material based on tyre scrapes and latex for thermal insulation is presented in this research work. Thermal and physical properties of the tire scrapes as well as latex were studied in order to use them as raw materials for the manufacture of the intended composite to be applied as a thermal insulator in hot and cold systems varying between 0?C and 200oC, respectively. Composite blankets were manufactured manually, in weight proportions of 1:1 (50:50%); 1:2 (33:67%) and 2:1 (67:33%) (tire scrapes: latex) respectively. Physical, mechanical and thermal properties of the composites were analyzed to obtain data about the viability of using the composite as a thermal insulator. The analyses carried out were based on standards ABNT, ASTM and UL. The maximum temperature obtained for the composite as a thermal insulator was 200?C, which meets the range of applications that could be used as a thermal insulator in domestic as well as industrial purposes. The experimental results prove that the composite can be used as a thermal insulator on heated or cooled surface / A reciclagem tem sido muito estimulada pelo mercado. J? existem v?rios produtos que s?o produzidos com materiais reciclados e v?rios res?duos t?m sido estudados nas mais diversas formas de aplica??es. A grande maioria das aplica??es de isolamento t?rmico em sistemas dom?sticos, comerciais e industriais na faixa de baixas e m?dias temperaturas (at? 180?C), utilizam materiais agressivos ? natureza tais como: l? de vidro, l? de rocha, poliuretano, poliestireno. Tais materiais, apesar da efic?cia na reten??o do fluxo de calor, t?m custo elevado e quando descartados demoram anos para serem absorvidos pela natureza. Dessa forma, tentando adequar-se a uma pol?tica mundial acerca da preserva??o do meio ambiente, foi realizado um estudo com o intuito de desenvolver um isolante t?rmico composto de materiais naturais/biodegrad?veis e rejeitos industriais. Com isso, esta pesquisa apresenta o desenvolvimento de um material comp?sito a base de raspas de pneu e l?tex para isolamento t?rmico. Para isso, analisou-se as propriedades t?rmicas e f?sicas da raspa de pneu e do l?tex visando a utiliza??o como mat?ria-prima para fabrica??o do comp?sito a ser aplicado como isolante t?rmico em sistemas quentes (at? 200?C) e frios (0?C). Atrav?s de processos manuais, foram fabricadas mantas do comp?sito nas propor??es em peso de 1:1 (50:50%); 1:2 (33:67%) e 2:1 (67:33%) (raspa de pneu : l?tex) respectivamente. Foram analisadas propriedades f?sicas e t?rmicas dos comp?sitos com intuito de obter dados sobre a viabilidade de uso como isolante t?rmico. As an?lises foram fundamentadas em normas ABNT, ASTM e UL. O limite de temperatura de trabalho obtido para o comp?sito foi de 200?C, que se encontra na faixa de aplica??es que abrangem desde o uso domestico at? o industrial. Os resultados obtidos experimentalmente comprovaram que o comp?sito, pode ser utilizado para fins de isolamento t?rmico tanto em superf?cies aquecidas como resfriadas

Les matériaux composites ont connu ces dernières années une forte croissance, croissance aujourd'hui renforcée par les nouvelles normes européenne visant à diminuer les émissions CO2 d'ici 2020. La réalisation de pièces complexes peut poser de nombreuses problématiques de fabrication comme la formation de zones sèches, ou la création de distorsions géométriques. Les origines de ces problématiques sont souvent liées à un manque de connaissance et de maîtrise des phases d'imprégnation des renforts et de cuisson du matériau. L'amélioration de la robustesse des procédés nécessite d'avoir une connaissance fine des phénomènes physiques qui ont lieu lors de l'élaboration. Dans cette perspective, les procédés d'élaboration de matériaux composites ont été étudiés à travers la mise en place d'un démonstrateur de laboratoire dans le cadre du projet LCM Smart. Ce pilote d'injection a permis de valider des solutions d'instrumentation, à partir de capteurs innovants (OFS) développés en partenariat avec le laboratoire d'optique Hubert Curien.L'application de cette instrumentation dans le cadre du suivi du procédé RTM a démontré les capacités des OFS pour le suivi des caractéristiques physiques de la pièce (le front d'écoulement, la température, les déformations résiduelles et le degré de cuisson). La comparaison des caractéristiques mesurées avec des simulations numériques effectuées en collaboration avec ESI, a montré une bonne corrélation.Enfin, l'instrumentation a permis de mettre en évidence l’intérêt d’un outillage composite en HexTool pour la réduction des contraintes résiduelles liées à l'interaction outil/pièce. / A significant growth in production and consumption of composite materials can be seen recently; growth reinforced by the new European standards, aimed at reducing CO2 emissions by the year 2020.The producing of complex parts can cause many difficulties for manufacturing because of their geometries and / or their constituents (using of various materials). For example, dry zones or geometric distortion formation. The origins of these difficulties are often related to a lack of knowledge and control of the reinforcement's impregnation phases and material curing.Improving the robustness of the processes demands a detailed knowledge of physical phenomena that occur during the producing. For this, we studied the composite materials production through the implementation of a laboratory demonstrator in the project LCM Smart. This pilot injection was used to validate instrumentation solutions, from innovative sensors (OFS) developed in partnership with the optical laboratory Hubert Curien. The application of this instrumentation in the context of RTM process monitoring in the development of simple parts has demonstrated the capabilities of OFS to control physical characteristics of the part (the flow front, temperature, residual strain and curing degree). The comparison of the measured characteristics with numerical simulations carried out in collaboration with ESI showed a good correlation.Finally, instrumentation has demonstrated the capacity of composite tool made by HexTool to minimize the residual stresses due to the tool/part interaction.

The epoxy resin has a widespread use in the manufacture of polymer composites to obtain various elements of structural engineering. The overall objective of this research is to evaluate the effect of reinforcing fabric architecture fiber-based Kevlar 49 and glass S on the mechanical performance of composites with epoxy matrix. It was observed that the mechanical performance of the epoxy resin and the composite, after natural aging and in seawater at a temperature of 70 ° C. Three architectures are designed for the production of tissue related to the structural reinforcement of the composite element: only aramid (Kevlar 49), and hybrid Kevlar 49 and glass S; varying the type of yarn and intertwining of the composition (fiber content in percentage) in each frame. The composite plates were made by hand casting process with epoxy matrix reinforced with woven fabrics of Kevlar fiber and Kevlar hybrid/glass, according to an innovative architecture. The mechanical properties of the composites were determined by tensile, bending and impact carried out in parallel and perpendicular to the warp direction. We used scanning electron microscopy to observe the reinforcement and matrix fractures after the mechanical tests. The composites with hybrid structure of Kevlar/glass on reinforcing fabric showed the best results with respect to the specific strength and impact energy. / A resina epóxi possui uma ampla utilização na fabricação de compósitos poliméricos, para obtenção de diversos elementos da engenharia estrutural. O objetivo geral desta Tese é avaliar o efeito da configuração do tecido de reforço à base de fibras de Kevlar 49 e vidro S no desempenho mecânico de compósitos com matriz epoxídica. Observou-se o desempenho mecânico da resina epóxi e do compósito, após envelhecimento natural ao ar livre e na água do mar sob temperatura de 70 ºC. Foram concebidas três configurações para produção do tecido referentes ao elemento de reforço estrutural do compósito: apenas em aramida (Kevlar 49), e híbrido de Kevlar 49 e fibra de vidro S; variando-se o tipo de entrelaçamento dos fios e composição (teor de fibra em percentual) em cada estrutura. Foram fabricadas placas do compósito pelo processo de moldagem manual com matriz epoxídica, reforçadas por tecidos planos em fibra de Kevlar, e híbrido Kevlar/vidro, de acordo com uma configuração inovadora. As propriedades mecânicas dos compósitos foram determinadas por ensaios de tração, flexão e impacto, realizados nas direções paralela e perpendicular ao urdume. Utilizou-se a microscopia eletrônica de varredura para observar as fraturas do reforço e matriz após os ensaios mecânicos. Os compósitos com estrutura híbrida de Kevlar/vidro no tecido de reforço apresentaram os melhores resultados com relação à resistência mecânica específica, bem como energia de impacto.

Ce travail porte sur l'étude du comportement mécanique d'une console courte en béton armé renforcée par collage de tissus en fibres de carbone et en particulier sur l'influence du nombre de couches de tissus en fibres de carbone, du type du renforcement, de l'orientation des tissus composites, du type de tissus en fibres de carbone. Les résultats montrent que la performance de la console n‘augmente pas linéairement en fonction de l'épaisseur de la plaque composite. Il existe une épaisseur optimale de tissus en fibres de carbone. Dans le cas du renforcement sur les deux faces du béton, il existe un nombre de couches optimales. Dans le cas du renforcement par bandage, l'épaisseur de matériaux composites plus intéressants est de trois couches. Par contre, la résistance de la console renforcée dépend fortement de la surface renforcée. Les résultats montrent également que le comportement d'une console renforcée peut être présenté en trois phases: la phase élastique globale, la phase de la propagation de fissures et la phase de l'ouverture des fissures diagonales. Le renforcement de la console permet d'augmenter considérablement la résistance ultime de 20 à 82% et la rigidité de la console. Les ruptures des consoles renforcées peuvent être résumées en cinq modes. En se basant sur les résultats obtenus et les modèles existants, la résistance ultime de la console renforcée et non renforcée a été estimée et analysée. Un modèle basant sur lа théorie de l'endommagement a été développé dans ce travail. L'effet de fatigue sur le comportement et sur la résistance ultime de la console courte renforcée a été également étudié dans ce travail. / This study deals with mechanical behaviour of strengthening reinforced concrete corbel by bonding carbon fibre sheet and in particular the influence of the number of layers of carbon fiber fabric, the type of strengthening, the orientation of the composite fabric and the type of carbon fiber fabrics .The results show that the performance of the corbel does not increase linearly with the thickness of the composite plate. There is an optimum thickness of the carbon fiber fabrics. In the case of strengthening on both sides of the concrete, there are an optimum number of layers. In the case of fully wrapped strengthening, the most interesting thickness of the composite is three layers. However, the resistance of the strengthening reinforced concrete corbel depends strongly on the bonded surface.The results also show that the behavior of strengthening corbel can be presented in three phases: the overall elastic phase, the phase of crack propagation and the phase of the opening of diagonal cracks. Strengthening the corbel can significantly increase the ultimate strength from 20% to 82 % and the stiffness of the corbel. The failure of the strengthening corbel can be summarized in five modes.Based on the results obtained and the existing models, the ultimate strength of the strengthening corbel or without strengthening, was estimated and analyzed. A model based on damage theory has been developed in this work. The effect of fatigue on the behavior and ultimate strength of the reinforced concrete corbel has also been studied.