Este trabalho investigou a influência da atmosfera de sinterização sobre as propriedades elétricas de porcelanas aluminosas contendo diferentes concentrações de Fe2O3, sinterizadas em condições oxidantes e redutoras. A influência de tais variáveis sob a microestrutura, fases formadas e as propriedades elétricas foram investigadas com o auxílio de técnicas como difração de raios x, microscopia eletrônica de varredura e por espectroscopia de impedância. Os corpos cerâmicos foram formulados a partir de uma formulação obtida da literatura, considerada aplicável para porcelanas aluminosas de alto desempenho: 30 %p de feldspato, 30 %p de caulim e 40 %p de alumina. As formulações contendo diferentes concentrações de Fe2O3 foram divididas em dois grupos. Um primeiro queimado em ar atmosférico para criar a condição oxidante e um segundo queimado em solução gasosa CO/CO2 para criar uma condição redutora. Para as condições redutoras utilizou-se uma técnica conhecida como “cama de grafite”. As temperaturas de queima praticadas foram 1200, 1250 e 1300 °C. A análise dos corpos cerâmicos após queima indicou que todas as amostras apresentaram mullita e coríndon como fases majoritárias e pequenas frações de quartzo. Hematita e ferro metálico foram observados para as amostras contendo elevada concentração de Fe2O3. Para as condições oxidantes, a adição de Fe2O3 provocou uma diminuição na resistividade das amostras. A maior resistividade elétrica apresentada pela amostra contendo 3 %p de Fe2O3 foi atribuída à elevada presença de mullita. A presença de hematita para as amostras contendo acima de 3%p de Fe2O3 foi considerada como responsável pela diminuição na resistividade elétrica. A adição de Fe2O3 resultou em um aumento na resistividade das amostras sinterizadas em atmosfera oxidante. Esse aumento foi atribuída à elevada quantidade de fase vítrea de baixa condutividade e ao elevado número de poros para formulações contendo > 3%p de Fe2O3. Os resultados permitiram concluir que embora a presença de 3 %p de Fe2O3 seja vista como a concentração máxima aceitável, maiores teores de Fe2O3 podem ser utilizados para a produção de isoladores elétricos de porcelana. / This study investigates the influence of sintering atmosphere on the electrical properties of aluminous porcelains containing different concentrations of Fe2O3, sintered in oxidizing and reducing conditions. The influence of these variables on the microstructure, phase formation and electrical properties were investigated with the aid of techniques such as X-ray diffraction, scanning electron microscopy and impedance spectroscopy. The ceramic bodies were made from a formulation obtained from literature, aluminous porcelains considered applicable to High Performance: feldspar 30 wt%, 30 wt% kaolin and 40 wt% alumina. Formulations containing different concentrations of Fe2O3 were divided into two groups. A first burned in the atmospheric air to create the oxidizing condition and a second solution burned gas CO/CO2 to create a reducing condition. For the reducing conditions employed a technique known as "bed graphite." The firing temperatures were 1200, 1250 and 1300 ° C. The analysis of the ceramic bodies after sintering indicated that all samples showed corundum and mullite as major phases and small fractions of quartz. Hematite and metallic iron were observed for samples containing high concentration of Fe2O3. For oxidizing conditions, the addition of Fe2O3 caused a decrease in the resistivity of the samples. The higher electrical resistivity presented by the sample containing 3 wt% Fe2O3 was attributed to the high presence of mullite. The presence of hematite for samples containing up to 3 wt% Fe2O3 was considered responsible for the decrease in electrical resistivity. The addition of Fe2O3 resulted in an improvement in resistivity of the sample sintered in oxidizing atmosphere. This improvement is attributed to the high amount of glassy phase of low conductivity and high number of pores for formulations containing> 3 wt% Fe2O3. The results showed that although the presence of 3 wt% Fe2O3 is seen as the maximum acceptable concentration, higher concentrations of Fe2O3 can be used for the production of electrical porcelain insulators.

Este trabalho investigou a influência da atmosfera de sinterização sobre as propriedades elétricas de porcelanas aluminosas contendo diferentes concentrações de Fe2O3, sinterizadas em condições oxidantes e redutoras. A influência de tais variáveis sob a microestrutura, fases formadas e as propriedades elétricas foram investigadas com o auxílio de técnicas como difração de raios x, microscopia eletrônica de varredura e por espectroscopia de impedância. Os corpos cerâmicos foram formulados a partir de uma formulação obtida da literatura, considerada aplicável para porcelanas aluminosas de alto desempenho: 30 %p de feldspato, 30 %p de caulim e 40 %p de alumina. As formulações contendo diferentes concentrações de Fe2O3 foram divididas em dois grupos. Um primeiro queimado em ar atmosférico para criar a condição oxidante e um segundo queimado em solução gasosa CO/CO2 para criar uma condição redutora. Para as condições redutoras utilizou-se uma técnica conhecida como “cama de grafite”. As temperaturas de queima praticadas foram 1200, 1250 e 1300 °C. A análise dos corpos cerâmicos após queima indicou que todas as amostras apresentaram mullita e coríndon como fases majoritárias e pequenas frações de quartzo. Hematita e ferro metálico foram observados para as amostras contendo elevada concentração de Fe2O3. Para as condições oxidantes, a adição de Fe2O3 provocou uma diminuição na resistividade das amostras. A maior resistividade elétrica apresentada pela amostra contendo 3 %p de Fe2O3 foi atribuída à elevada presença de mullita. A presença de hematita para as amostras contendo acima de 3%p de Fe2O3 foi considerada como responsável pela diminuição na resistividade elétrica. A adição de Fe2O3 resultou em um aumento na resistividade das amostras sinterizadas em atmosfera oxidante. Esse aumento foi atribuída à elevada quantidade de fase vítrea de baixa condutividade e ao elevado número de poros para formulações contendo > 3%p de Fe2O3. Os resultados permitiram concluir que embora a presença de 3 %p de Fe2O3 seja vista como a concentração máxima aceitável, maiores teores de Fe2O3 podem ser utilizados para a produção de isoladores elétricos de porcelana. / This study investigates the influence of sintering atmosphere on the electrical properties of aluminous porcelains containing different concentrations of Fe2O3, sintered in oxidizing and reducing conditions. The influence of these variables on the microstructure, phase formation and electrical properties were investigated with the aid of techniques such as X-ray diffraction, scanning electron microscopy and impedance spectroscopy. The ceramic bodies were made from a formulation obtained from literature, aluminous porcelains considered applicable to High Performance: feldspar 30 wt%, 30 wt% kaolin and 40 wt% alumina. Formulations containing different concentrations of Fe2O3 were divided into two groups. A first burned in the atmospheric air to create the oxidizing condition and a second solution burned gas CO/CO2 to create a reducing condition. For the reducing conditions employed a technique known as "bed graphite." The firing temperatures were 1200, 1250 and 1300 ° C. The analysis of the ceramic bodies after sintering indicated that all samples showed corundum and mullite as major phases and small fractions of quartz. Hematite and metallic iron were observed for samples containing high concentration of Fe2O3. For oxidizing conditions, the addition of Fe2O3 caused a decrease in the resistivity of the samples. The higher electrical resistivity presented by the sample containing 3 wt% Fe2O3 was attributed to the high presence of mullite. The presence of hematite for samples containing up to 3 wt% Fe2O3 was considered responsible for the decrease in electrical resistivity. The addition of Fe2O3 resulted in an improvement in resistivity of the sample sintered in oxidizing atmosphere. This improvement is attributed to the high amount of glassy phase of low conductivity and high number of pores for formulations containing> 3 wt% Fe2O3. The results showed that although the presence of 3 wt% Fe2O3 is seen as the maximum acceptable concentration, higher concentrations of Fe2O3 can be used for the production of electrical porcelain insulators.

Submitted by Carla Vanessa de Sousa Coelho (carla.vsc1@gmail.com) on 2017-04-20T00:15:41Z No. of bitstreams: 1 Dissertação Final - Carla Vanessa de Sousa Coelho.pdf: 6604506 bytes, checksum: 562e1e39ade39113613afe9bf2981de5 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-25T16:20:11Z (GMT) No. of bitstreams: 1 coelho_cvs_me_rcla.pdf: 6604506 bytes, checksum: 562e1e39ade39113613afe9bf2981de5 (MD5) / Made available in DSpace on 2017-04-25T16:20:11Z (GMT). No. of bitstreams: 1 coelho_cvs_me_rcla.pdf: 6604506 bytes, checksum: 562e1e39ade39113613afe9bf2981de5 (MD5) Previous issue date: 2017-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Observações de campo, petrografia, geoquímica e mineralogia em dois perfis de alteração de solo dos arenitos provenientes do Membro Serra da Galga, Formação Marília, foram utilizados para avaliar a possível relação genética entre os materiais lateríticos e os solos enriquecidos com argilas aluminosas (argilas refratárias). O estudo focou um sistema Latossolo-Gleissolo presente na superfície da chapada sedimentar. O afloramento do Latossolo, com crosta ferruginosa, situa-se na borda da chapada e o Gleissolo, onde estão concentradas as argilas aluminosas, está localizado na depressão topográfica hidromórfica. As fácies petrográficas mostram que a couraça ferruginosa é autóctone, formada no nível saprolítico do arenito. O desmantelamento atual deste horizonte está associado com a desferruginização parcial em conseqüência ao aumento da umidade. A estrutura pisolítica é reconhecida tanto no perfil do Latossolo quando do Gleissolo, após a desferruginização. A associação caulinita e gibbsita predomina em todas as profundidades dos dois perfis, porém a caulinita é mais expressiva nas maiores profundidades e a gibbsita nas camadas superficiais. A desferruginização é o processo que acompanha a elevação do nível freático, seja formando horizontes manchados na base do Latossolo ou formando horizontes brancos no Gleissolo nos quais se concentram o alumínio. O enriquecimento de alumínio está associado com a dessilicificação, possivelmente relacionado com a diminuição do pH e a desestabilização da caulinita. Quartzo, raros minerais de turmalina, cianita, zircão e rutilo compõem a fase dos minerais resistentes ao intemperismo químico. A goethita é o óxido de ferro predominante, resultado de meio hidratado. O modelado plano da chapada, que corresponde à Superfície Sul-Americana descrita por King (1956), sob condições climáticas adequadas e prolongadas, favoreceu a formação de cobertura encouraçada ferruginosa. Após o término da deposição sedimentar, no Paleoceno inferior (aproximadamente 65 milhões de anos AP), a superfície foi truncada por longos períodos de erosão que aplainaram o relevo. Atualmente, o clima é tropical com forte sazonalidade e aumento da umidade. Esta nova condição hídrica, de saturação, somada às condições de estabilidade tectônica e vegetação esparsa exerce influência na lixiviação e a perda ferro no horizonte de argila aluminosa. Os resultados sugerem que é possível a formação de material aluminoso a partir de uma crosta ferruginosa, propondo assim uma hipótese autóctone para o desenvolvimento das argilas aluminosas. / Field observation, petrography, geochemistry and mineralogy in two weathered soil profiles of the sandstones from Member Serra da Galga, Marilia Formation, were used to evaluate the possible genetic relation between the lateritic material and the soils enriched in aluminous clays (refractory clays). The study focus was an Oxisol-Gleysol system present in the surface of the sedimentary plateau. The Oxisol outcrop, with ferruginous duricrust, is situated on the edge of the plateau and the Gleysol, where the aluminous clay is concentrated, is located in the hydromorphic topographic depression. The petrographical facies show that the ferruginous duricrust is authochthonous, formed in the saprolitic level of the sandstone. The current dismantling of this horizon is associated with the partial deferruginization due to humidity increase. The pisolitic structure is recognized both in the Oxysol profile and Gleysol, after deferruginization. The kaolinite and gibbsite association prevails in all depth of both profiles, albeit kaolinite is more significant in deeper depths and gibbsite in the superficial layers. Deferruginization is a process that accompanies groundwater level rise, might develop mottled horizons at the Oxysol base or forming white horizons at the Gleysol in which the aluminum is concentrated. The aluminum enrichment is associated with the dessilicification, possibly related with decrease in pH and the kaolinite destabilization. Quartz, rare tourmaline, kyanite, zircon and rutile minerals make up the phase of minerals resistant to chemical weathering. Goethite is the dominant iron oxide, outcome of a hydrated environment. The flat shape of the plateau, which corresponds to the South American Surface described by King (1956), under appropriate and prolonged weather conditions, favored the formation of the hard ferruginous coverage. After the end of sedimentary deposition, in early Paleocene (approximately 65 million years BP), the surface was truncated by long erosion periods that flattened the relief. Currently the weather is tropical with strong seasonality and humidity increase. This new hydrological condition, saturated, combined with stable tectonic conditions and sparse vegetation exerts influence in leaching and loss of iron in the aluminous clay horizon. The results suggests that is possible the formation of a aluminous material from a ferruginous duricrust, proposing an autochthonous hypothesis for the development of the aluminous clays.

Este trabalho investigou a influência da atmosfera de sinterização sobre as propriedades elétricas de porcelanas aluminosas contendo diferentes concentrações de Fe2O3, sinterizadas em condições oxidantes e redutoras. A influência de tais variáveis sob a microestrutura, fases formadas e as propriedades elétricas foram investigadas com o auxílio de técnicas como difração de raios x, microscopia eletrônica de varredura e por espectroscopia de impedância. Os corpos cerâmicos foram formulados a partir de uma formulação obtida da literatura, considerada aplicável para porcelanas aluminosas de alto desempenho: 30 %p de feldspato, 30 %p de caulim e 40 %p de alumina. As formulações contendo diferentes concentrações de Fe2O3 foram divididas em dois grupos. Um primeiro queimado em ar atmosférico para criar a condição oxidante e um segundo queimado em solução gasosa CO/CO2 para criar uma condição redutora. Para as condições redutoras utilizou-se uma técnica conhecida como “cama de grafite”. As temperaturas de queima praticadas foram 1200, 1250 e 1300 °C. A análise dos corpos cerâmicos após queima indicou que todas as amostras apresentaram mullita e coríndon como fases majoritárias e pequenas frações de quartzo. Hematita e ferro metálico foram observados para as amostras contendo elevada concentração de Fe2O3. Para as condições oxidantes, a adição de Fe2O3 provocou uma diminuição na resistividade das amostras. A maior resistividade elétrica apresentada pela amostra contendo 3 %p de Fe2O3 foi atribuída à elevada presença de mullita. A presença de hematita para as amostras contendo acima de 3%p de Fe2O3 foi considerada como responsável pela diminuição na resistividade elétrica. A adição de Fe2O3 resultou em um aumento na resistividade das amostras sinterizadas em atmosfera oxidante. Esse aumento foi atribuída à elevada quantidade de fase vítrea de baixa condutividade e ao elevado número de poros para formulações contendo > 3%p de Fe2O3. Os resultados permitiram concluir que embora a presença de 3 %p de Fe2O3 seja vista como a concentração máxima aceitável, maiores teores de Fe2O3 podem ser utilizados para a produção de isoladores elétricos de porcelana. / This study investigates the influence of sintering atmosphere on the electrical properties of aluminous porcelains containing different concentrations of Fe2O3, sintered in oxidizing and reducing conditions. The influence of these variables on the microstructure, phase formation and electrical properties were investigated with the aid of techniques such as X-ray diffraction, scanning electron microscopy and impedance spectroscopy. The ceramic bodies were made from a formulation obtained from literature, aluminous porcelains considered applicable to High Performance: feldspar 30 wt%, 30 wt% kaolin and 40 wt% alumina. Formulations containing different concentrations of Fe2O3 were divided into two groups. A first burned in the atmospheric air to create the oxidizing condition and a second solution burned gas CO/CO2 to create a reducing condition. For the reducing conditions employed a technique known as "bed graphite." The firing temperatures were 1200, 1250 and 1300 ° C. The analysis of the ceramic bodies after sintering indicated that all samples showed corundum and mullite as major phases and small fractions of quartz. Hematite and metallic iron were observed for samples containing high concentration of Fe2O3. For oxidizing conditions, the addition of Fe2O3 caused a decrease in the resistivity of the samples. The higher electrical resistivity presented by the sample containing 3 wt% Fe2O3 was attributed to the high presence of mullite. The presence of hematite for samples containing up to 3 wt% Fe2O3 was considered responsible for the decrease in electrical resistivity. The addition of Fe2O3 resulted in an improvement in resistivity of the sample sintered in oxidizing atmosphere. This improvement is attributed to the high amount of glassy phase of low conductivity and high number of pores for formulations containing> 3 wt% Fe2O3. The results showed that although the presence of 3 wt% Fe2O3 is seen as the maximum acceptable concentration, higher concentrations of Fe2O3 can be used for the production of electrical porcelain insulators.

This thesis deals with refractory concrete binding system based on aluminous cement and phosphoric acid. The prepared refractory concretes were fired at 1 000 °C. Various effects on compressive strength of refractory concrete were studied. The influence of aluminous cement content and phosphoric acid content, the influence of various admixtures, the influence of plasticizers and the influence of time and method of sample storage were studied. Simultaneous thermogravimetry and differential thermal analysis of the basic unfired sample were performed. Finally, selected refractory concretes were fired at 110, 200, 400, 600, 800, 900, 1 000 and 1 100 °C. The compressive strength of these samples was measured and powder X ray diffraction analysis was performed. The compressive strength of refractory concretes under intermediate temperatures (800–1 100 °C) was most increased in samples with metakaolin and gray microsilica.

The diploma thesis is focused on study of diagnostic methods used for reinforced concrete structure with a practical example of a survey on the subject of the original memorial Bata in Zlin, today's House of Art. The theoretical part of the thesis describes the general methodology of the survey with the distribution methods for testing materials and structures, and displays the evaluation according to ČSN ISO 1382 Also deals with the required properties and used by diagnostic methods for concrete and steel. In the practical part of the surveyed, which is supposed to show the methodology of the survey to the evaluation process involving the setting apart of strength and classification of concrete and chemical analysis, which should show whether the concrete is not based on aluminous cement.

Les liants ettringitiques dont la composition est formée principalement par du ciment d’aluminate de calcium et par du sulfate de calcium, sont très utilisés dans le cadre des mortiers techniques pour des applications telles que les mortiers de ragréage, les chapes autonivelante, les mortiers de réparation…. en raison de leurs propriétés de durcissement rapide et de résistance initiale élevée. Néanmoins, en fonction de la quantité des matières premières utilisées dans la composition et de leur nature, ces liants peuvent présenter à jeune âge ainsi qu’à long terme, des comportements différents. En particulier et dans le cadre de ce travail, l’influence de la nature et du dosage en sulfate de calcium sur l’hydratation des mortiers ettringitiques comme le début de prise, le changement de l’état liquide à l’état solide, les variations dimensionnelles, la résistance et le vieillissement à long terme (jusqu’à 330 jours) pour différentes conditions de conservations ont été déterminées. Ces caractéristiques ont été évaluées selon différentes techniques expérimentales de rhéologie, de mesure des variations volumiques, de calorimétrie isotherme, de spectroscopie infrarouge, de porosimétrie par intrusion de mercure, de diffraction des rayons X et thermogravimétrie. / The ettringite binder whose composition is mainly formed by the calcium aluminate cement and calcium sulfate, are widely used in mortars for technical applications such as patching mortars, the self -leveling screeds, repair mortars etc… thanks to their fast hardening ability and high early strength. However, depending on the amount and types of raw materials used in the composition, the properties of these types of binder have different behaviors at early age and at long-term. And in particular in this work, the influence of the nature and dosage of calcium sulfate on the consequences of ettringite mortars hydration as the beginning of setting time, the change from the liquid state to the solid state, dimensional change, the resistance, porosity, the progress of hydration and ageing until 330 days at different conservation conditions were determined. These characteristics were assessed by different experimental techniques such as rheology, chemical shrinkage, autogenous shrinkage, isothermal calorimetry, infrared spectroscopy, mercury intrusion porosimetry, X-ray diffraction, Thermogravimetric analysis.

In this diploma thesis is accomplished description of existing condition of decorating linear tractive unit. Analysis of safety requirements for linear tractive unit is also accomplished. Eligible construction concept of frame of electromechanical linear tractive unit is chosen. Selection and calculation of ball screw and nut is made also with draft of its eligible support . Choose of eligible engine and clutch for gearing of engine torque from engine to the ball screw is done too. Further is designed eligible concept of gearing of the rotary motion of ball screw to straight motion of bottom pulley block, which now interacting with upper firm pulley block provides lifting of tensile rod with coulisse.

Afin de renforcer et de protéger les structures du Génie Civil vis-à-vis des incendies, un programme de recherche a été entrepris sur le développement d'un nouveau matériau composite TRC. Le composite TRC est généralement constitué de deux composants, le renfort textile et la matrice cimentaire. Les nouveaux composites du projet sont formulés d'une matrice phosphatique ou alumineuse avec des renforts textiles continus utilisant le verre, le carbone ou des hybrides. L'objectif de ce travail est d'examiner et de développer un TRC satisfaisant les critères de performances thermomécaniques. Le premier niveau de conception est de définir une méthodologie de caractérisation permettant d'identifier les caractéristiques thermomécaniques et les propriétés physico-chimiques des TRC à haute température. Plusieurs régimes de chargement thermique et mécanique couplé ainsi que des analyses thermiques ont été appliqués et pris en compte pour les différentes formulations de TRC. Dans une première partie expérimentale, l'effet du refroidissement et de la nature de la matrice sur le comportement thermomécanique de TRC a été étudié. La deuxième partie des essais explore le comportement thermomécanique et thermo-physico-chimique de deux familles de TRC. La première famille était formée d'une matrice phosphatique et des fibres de verre E. Cette partie concerne l'adhérence qui peut être développée au niveau de l'interface fibre-matrice par deux géométries différentes de textile verre E. L'efficacité du renfort est améliorée ensuite par une pré-imprégnation par une résine époxy. La deuxième famille de composite traite le renforcement d'une matrice alumineuse par des grilles de carbone. Cette famille a subi plusieurs modifications. Un chargement de la matrice par de l'alumine et de verre micronique n'a pas été suffisant pour améliorer le comportement du TRC. Une nouvelle grille de carbone a été ensuite utilisée et des couches de fibres discontinues de verre Mat AR ont été insérées dans la matrice. Ces couches de Mat AR créaient une bonne isolation thermique mais présentaient un problème de délaminage. Enfin l'ajout des fibres de polypropylène au sein d'un mortier alumineux à granulométrie étagée présentait des résultats satisfaisants. Après la recherche et la validation du TRC le plus performant, la fonction de " bouclier thermique " des matériaux isolants a été traitée afin d'améliorer la stabilité thermomécanique des TRC / In order to strengthen and protect civil engineering structures from fires, a research program was undertaken for the development of new TRC composite materials. The TRC composite generally consists of two components, the textile reinforcement and the cement matrix. The new composites of the project are formulated with an inorganic phosphate cement or an aluminous matrix with continuous textile reinforcements using glass, carbon or hybrids. The purpose of this work is to examine and develop TRC that meets the thermomechanical performance criteria. The first level of design is to define a characterization methodology, which identifies the thermomechanical characteristics and physicochemical properties of TRC subjected to high temperature. Several coupled thermal and mechanical loading regimes as well as thermal analyses were applied and taken into account for different TRC formulations. In a first experimental part, the nature of the matrix and the cooling effect on the thermomechanical behaviour of TRC were studied. The second part of the experimental work explores the thermomechanical and thermo-physico-chemical behaviour of two families of TRC. The first family of TRC was formed of a phosphate cement and E-glass textile. It examines the bond that can be developed through the fibre-matrix interface by two different geometries of textile. The effectiveness of the reinforcement is then improved by a pre-impregnation by a resin epoxy. The second family of TRC deals with the reinforcement of an aluminous matrix by carbon grids. This family has undergone several changes. Filling of the matrix with alumina and micron glass was not sufficient to improve the behaviour of TRC. A new carbon grid was then used and layers of Mat AR glass fibres were inserted into the matrix. These layers of Mat AR created good thermal insulation but presented a delamination problem. Finally, the addition of polypropylene fibres in an aluminous mortar with graded granulometry showed satisfactory results. After the search and validation of the most efficient TRC, the "heat shield" function of insulating materials was processed to improve the thermomechanical stability of TRC

Les sulfates de calcium sont des matériaux économiques et écologiques. Pourtant leur utilisation dans le domaine de la construction est assez limitée du fait de leur sensibilité à l’eau. La capacité des ciments alumineux (CAC) à diminuer la sensibilité à l’eau des sulfates de calcium ainsi que les mécanismes d’insensibilisation ont été étudiés. L’insensibilisation à l’eau des sulfates de calcium a été réalisée par ajout de faibles quantités de ciment alumineux (≤ 30%). Quatre sulfates de calcium de nature différente : gypse, hémi-hydrate α et β, anhydrite synthétique ont été étudiés. L’étude des mécanismes d’insensibilisation à l’eau des sulfates de calcium par ajout du ciment Fondu, menée à différentes analyses de la microstructure : IR, DRX, ATD-TG, MEB, a mis en évidence deux approches : la formation de l’ettringite insoluble et la formation du gel d’AH3 qui colle les grains de sulfate de calcium soluble. La nature des phases cristallochimiques du ciment alumineux a des influences sur les caractéristiques mécaniques, la sensibilité à l’eau ainsi que la durabilité des mélanges [sulfate de calcium / CAC]. L’étude des mélanges [anhydrite synthétique / laitier / CAC] offrent des perspectives intéressantes notamment concernant le développement des liants à faible empreinte CO2. / Calcium sulphate materials are economical and ecological. But their use in the construction is quite limited because of their sensibility to water. The capacity of aluminate cement (CAC) to decrease the water sensibility of calcium sulphate and the mechanisms of insensibilisation were investigated. Waterproofing of gypsum base materials was carried out by addition of small amounts of aluminate cement (≤ 30%). Different nature of calcium sulphates : gypsum, hemihydrate α and β, synthetic anhydrite was studied. The study of mechanisms of insensibilisation to water of calcium sulphate by adding cement Fondu, with different analysis of microstructure : IR, DRX, ATD-TG, MEB, revealed two approaches : formation of ettringite insoluble and formation of gel AH3 that stick soluble grains of calcium sulphate. The nature of phases of aluminate cement has influences on the mechanical properties, sensibility to water and durability of mixtures [calcium sulphate / CAC]. The studies of mixtures [synthetic anhydrite / slag / CAC] offer interesting perspectives for the development of binders with low imprint CO2.