Tesi sul tema "Ciment – Propriétés physico-chimiques"
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Yapi, Amoncou Fidel. "Etude de la corrosion des armatures dans les mortiers composes : Influence du milieu de conservation : Apport de la chronopotentiométrie". Lyon, INSA, 1991. http://www.theses.fr/1991ISAL0075.
One of the most important damages of reinforced concrete constructions is the corrosion of steel reinforcement ; this last is aggravated by the presence of aggressive agents: acids, chlorides… Our research concern the study of corrosion possibility of steel reinforcement in motars made with different types of binders. We used artificial protland cement (CPA 55) as reference and the others binders are mixture of 70% CPA55 and 30 % of artificial pouzzolanic materials mainly calcined clay, fly ash, metakaolin, and slag. The specimens are cured in water or in solution containing 5% of MgCl 2 in order to study the influence of chlorides. Two methods are used to study the corrosion: voltamperometrical and chronopotentiometrical methods. In order to interpret electrochemical results, the evolution of microstructure is studied with physico chemical methods (ATD,IR, porosimetry. ) Chronopotentiometrical method give better informations with regard to steel corrosion in mortar. In solution containing MgC12, only the binder with 30% of metakaolin don't depassivate the reinforcement
Platel, David. "Impact de l'architecture macromoléculaire des polymères sur les propriétés physico-chimiques des coulis de ciment". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2005. http://pastel.archives-ouvertes.fr/pastel-00001497.
Le, Rouzic Mathieu. "Étude des propriétés physico-chimiques et mécaniques des matériaux cimentaires à base d’oxyde de magnésium". Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1082/document.
Magnesium phosphate cements are the most representative cements of the activated-by-acid cements family. Despite the fact that they are known since the early 20th century, their use in civil engineering is fairly limited. These materials are used for road repairs where the fast compressive strength development is an advantage. Recently they have also been used in wastes stabilization/solidification (S/S), especially with wastes incompatible with Portland cement. The challenges of the use of these cements are related to the nature of their formation reaction: fast, very exothermic, with a very short setting time (only a few minutes).The bonding phase, k-struvite (MgKPO4.6H2O), is obtained from magnesium oxide mixed in water with monopotassium phosphate (KH2PO4).MgO + KH2PO4 + 5H2O MgKPO4.6H2OThe setting mechanisms are still poorly known and various theories, involving or not secondary product formation, have been suggested. Our researches have aimed to understand the setting mechanisms, as well as the influence of the formulation parameters on the properties of the magnesium phosphate cement. Results show that the formation of k-struvite involved a precipitation-dissolution reaction of an intermediate product, the newberyite (MgHPO4.3H2O). Formation reactions of these two products are controlled by the supersaturation rate and the pH of the solution. The study highlights the strong effect of water on the properties of fresh cement paste. With a low mass ratio e/c in comparison of Portland cement (ratio e/c between 0,1 and 0,25), a slight modification of the ratio (0,02) leads to a segregation and a surface heterogeneity of the cement paste. Among the formulation parameters, the molar ratio MgO/KH2PO4 (Mg/P) seems the most important parameter. Indeed, it impacts most of the properties of the magnesium phosphate cement (compressive strength, setting time, reaction heat, paste fluidity …). Low Mg/P ratios lead to poor water resistance, to crystals formation inside the microstructure that can be seen on the surface of the sample (an efflorescence appearance), and to important swelling of the paste, leading to the cracking of the samples. After the parametric study, a magnesium phosphate cement paste has been defined. Dimensional changes and chemical shrinkage measurement were conducted to understand the mechanisms involved in this swelling phenomenon. In support, microstructural analyses (SEM, XRD, TGA) and leaching tests complete the experimental campaign. The results confirm the influence of a low Mg/P ratio on cement swelling and water resistance. Finally, a study on various additions to the paste has been conducted, with the purpose of improving the cement paste performances. It shows that the addition of an inert filler (siliceous sand or fly ashes) has a retarding effect and reduced the reaction heat
Sedan, David. "Etude des interactions physico-chimiques aux interfaces fibres de chanvre/ciment : influence sur les propriétés mécaniques du composite". Limoges, 2007. http://aurore.unilim.fr/theses/nxfile/default/84a25f18-1c55-4565-bd8f-a95fa2e7ea73/blobholder:0/2007LIMO4055.pdf.
The use of hemp fibres in a cement material gives interesting properties to composites. The understanding of the interactions between the fibres and the cement matrix is essential to study mechanical behaviour of such composites. Hemp fibres, by a high content of pectins, fix calcium Ca2+ and hydroxyle OH- ions on their surface. A lack of hydroxyle and calcium ions is observed in the interstitial phase, which implies an inhibition of calcium silicate hydrates (CSH) responsible for the delay in setting time. Chemical attack of the fibres surface by an alkaline and calcium rich media, as cement paste, degrades hemicelluloses contained in the fibres and seems to roughen the surface. Quantities of sugars or uronic acids released by the fibres are too little to have an effect on the chemical properties of the solutions. Calcium ions fixation on hemp fibres surface implies a strong adhesion between them and cement matrix. So, an improvement of the mechanical properties of the composite is observed. The fibres network in composites permits an increase of the flexural strength associated to a rise of the displacement to rupture. Such composites could be consequently interesting in building applications
Guillon, Emmanuel. "Durabilité des matériaux cimentaires : modélisation de l'influence des équilibres physico-chimiques sur la microstructure et les propriétés mécaniques résiduelles". Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2004. http://tel.archives-ouvertes.fr/tel-00133395.
Serraj, Siham. "Mise au point et études mécaniques et physicochimiques d'un ciment hydrolique phosphocalcique à usage orthopédique et odontologique". Montpellier 1, 1999. http://www.theses.fr/1999MON13504.
Hadj-Aissa, Aurélie. "Corrélations entre les propriétés physico-chimiques et l’efficacité photocatalytique d’un matériau cimentaire enrichi en TiO2". Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10056.
More than half of the world population is exposed to urban air pollution which poses problems for the environment and human health. To reduce the background of the pollution in cities, an innovative cementitious material has been developed and used to degrade pollutants thanks to its photocatalytic properties induced by the addition of TiO2. This work was focused on the correlation between physicochemical properties and the photocatalytic efficiency of a mortar enriched with TiO2 during the degradation of two volatile organic compounds (VOCs), formaldehyde and toluene as well as a mixture of nitrogen oxides (NOx). The occurence rate of of titanium dioxide on the surface, the relative percentage of titanium and the absorptance of UV photons by TiO2, respectively, were determined by Raman spectroscopy, scanning electron microscopy coupled with X-ray analysis and UV-visible diffuse refectance spectroscopy. Proportionality between these three variables has been demonstrated. The photocatalytic efficiency of TiO2-rich cementitious materials has been demonstrated for the degradation of the 2 VOCs and also for NOx. The photocatalytic efficiency is related to the presence of TiO2 on the surface and the ability of TiO2 to absorb UV photons. The cement matrix can also, in the dark, reduced significantly the concentration of formaldehyde. The study of the influence of materials and environmental parameters showed the importance of the TiO2 content, the luminous flux and relative humidity on the photocatalytic properties of the mortar and allowed to contribute to a better understanding of the reactions occurring during the degradation of pollutants by a photocatalytic cementitious material
Tadier, Solène. "Étude des propriétés physico-chimiques et biologiques de ciments biomédicaux à base de carbonate de calcium : apport du procédé de co-broyage". Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT045H/document.
Implantation of bone substitute materials using minimally invasive surgical techniques requires specific properties for the material including resorbability, injectability and adequate radio-opacity. The control of such properties of the material is of prime importance to meet a surgeon's requirements. In this context, this study deals with two different mineral cements: the first one is only composed of calcium carbonate phases and the second one is a mixture of equal amount of calcium phosphate and calcium carbonate phases. An original methodology involving complementary analytical techniques was implemented to thoroughly investigate the grinding mechanism of separated or mixed reactive powders constituting the solid phase and its effects on cement reactivity and properties. We show that co-grinding the solid phase decreases the mean size of the particles and favours both a homogeneous mixing and good contact between the components, leading to a decrease in the setting time. We also set two original protocols designed to evaluate paste injectability and phase separation during paste extrusion. Co-grinding leads to synergistic positive effects on cement injectability and radio-opacity. It allows maintaining a low and constant load during the extrusion of paste, which composition remains constant. Moreover, the cement's mechanical properties can be enhanced by lowering the L/S ratio because of the lower plastic limit. To be able to follow in situ the injection of the bone cement using X-ray radiography, strontium has been introduced as a contrast agent in the cement composition. Two different routes have been investigated: SrCO3 has been added to the solid phase or SrCl2 has been dissolved in the liquid phase. We show that co-grinding process permits to homogenise strontium distribution in the cement allowing us to optimise the minimum amount of strontium to add into the cement paste to reach the radio-opacity required by ISO 9917-1 standard. Moreover, adding SrCl2 in the liquid phase makes the cement paste more viscous and diminishes its injectability. Release tests performed on Sr-loaded cements show a sustained release of strontium at 37°C and pH 7.4. Finally, in-vitro cell tests have shown the excellent behaviour of osteoprogenitor cells, especially on cements including SrCO3. The last part of this work deals with the study of the crystallization of aragonite CaCO3 in the presence of phosphate ions, naturally present in biological fluids, to better understand the setting ability of calcium carbonate cements in-vivo. Using the constant composition crystal growth technique, we show that the presence of phosphate ions, even in very low amount (concentration < 0.5 µM) diminishes both the nucleation and the crystal growth rates of aragonite. This work contributes to the optimization of the properties of calcium carbonate-based cements and a better understanding and control of their behaviours during implantation and their evolution in-vivo. From a fundamental point of view, this multidisciplinary work performed in model conditions in-vitro and completed by preliminary in-vivo experiments have underlined the interest in combining these two approaches to identify and understand the phenomena and the chemical reactions involved during the setting of biomedical cements
Tlaiji, Tala. "Développement et caractérisation du comportement thermomécanique des matériaux composites TRC". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1116/document.
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
Auriol, Mélodie. "Influence des interactions physico-chimiques entre particules et composés organiques sur la stabilité de mousses minérales". Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0241/document.
Cement-based mineral foams are solid porous materials and presentvery interesting insulating properties. Such materials are used in the constructionsector in order to reduce the energy consumption of houses. However, theproduction of these materials can be difficult because of the kinetic competitionbetween foam stability and cement setting. Cement-based mineral foams areextremely complex materials because of the number of components and all theirinteractions. The objective of our study is to get insight into the interactions betweenmineral and organic compounds and to understand their role in the stabilizingmechanisms. Our strategy was to study a model system, sufficiently close the realone to be representative, and sufficiently simple to identify the contribution of thedifferent components. We used as a foaming agent a surfactant exhibiting acharacteristic peak in UV-visible spectroscopy in order to determine its function andposition in the complex system. We first worked on unfoamed slurries, then westudied thin liquid films and the foamed materials
Chadfeau, Calypso. "Caractérisations multiéchelles de surfaces cimentaires de parement en fonction de différentes surfaces coffrantes". Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAD005.
The objective of this work is to study the interaction between cement and different types of formwork surfaces by analysing the surface condition of the raw cement paste 24 hours old and that of formwork surfaces at different scales as well as their demoulding performance. Surface characterisation procedures combining interferometry, SEM + EDS, Raman spectroscopy and AFM Peak Force are developed. These multiscale characterisations allow the demonstration of the impact of the physico-chemical properties of formwork surfaces on cementitious surfaces at different scales and the analysis of their influence on adhesion to formwork. The effect of surface geometry and surface energy of formwork surfaces on the morphological, chemical and mechanical characteristics of cement surfaces is analysed, from millimetre to nanometre, with a discussion on the possible characterisation of cement phases more or less hydrated
Li, Mengya. "Caractérisation expérimentale et modélisation du panneau composite bois-ciment". Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0302.
Lightweight concretes made from wood fibres and Portland cement paste are a new alternative for the reduction of the environmental impact of buildings. They are used in sustainable constructions as secondary elements for their thermal, hydric and mechanical performance. However, the generalisation of their use is not possible without resolving certain scientific obstacles related to their characterisation. Hence the aim of the present work, which is to contribute towards their characterisation through experimentation and numerical simulation. The Young's modulus and tensile strength were measured through flexural and compression tests. A numerical model has also been developed to predict the behaviour of specimens under bending test as well as their structural response when used as permanent formwork. In particular, the model helps to choose the optimum parameters for a better design of the formwork system. The study of the hygrothermal behaviour of the wood-cement material was carried out using both experimental work and simulation. The equations of coupled heat and moisture transfers for a porous medium have been implemented in the Comsol Multiphysics® software. The developed model has been applied and validated on several dynamic responses resulting from hygro-thermal tests carried out in the laboratory. The obtained physico-thermal properties of the wood-cement composite material were then incorporated into the Abaqus code via a Umatht user subroutine to simulate its high temperature behavior. The temperature profiles are evaluated and compared with the charring tests performed using a radiant panel on samples exposed to a uniform heat flux of 6kW/m². The simulations show that the developed model is able to predict the temperature profiles, the area and the depth of the charred layer during fire exposure
Chabrat, Nicolas. "Impact des conditions environnementales sur le comportement à long terme de sols traités". Electronic Thesis or Diss., Université de Lorraine, 2024. http://www.theses.fr/2024LORR0004.
Lime and/or cement stabilization is a common solution for improving the mechanical performance of fine soils. Treatment limits the shrinkage and swelling effect of clayey soils. However, while numerous laboratory studies have been carried out on treated materials, little is known about the in situ performance of such stabilised materials several years after construction, and very few studies are available, especially in the case of stabilised expansive soils. As a result, existing methods and procedures are generally unable to assess the alteration caused by the environmental conditions of a treated soil. This thesis addresses these issues by studying an experimental embankment at Héricourt (France). Built in 2010 as a part of the ANR TerDOUEST project, this embankment was built with a highly plastic clayey soil. The clay was treated with lime and/or cement upon construction. An initial assessment of the state of the backfill was carried out 11 years after construction of the structure, with horizontal and vertical corings. The hydromechanical characterisation of the treated clay was carried out with multiple oedometer tests. The compressibility of the material sampled by horizontal coring was determined, making it possible to assess changes in the mechanical behaviour of the treated soil as a function of its proximity to the edge of the embankment. The results showed that the materials located in the internal part of the embankment have a mechanical behaviour similar to that of the soil treated in the laboratory after a 180-day curing time at constant moisture content. On the other hand, a gradual deterioration of the mechanical properties of the material was observed as it approached the outer part of the embankment. The mechanical properties of the materials taken from the outer part were equivalent to those of the untreated soil. The microstructure (mercury intrusion porosimetry, scanning electron microscopy), chemical composition (thermogravimetric analysis, X-ray fluorescence) and mineralogical composition (X-ray diffraction) of the treated soil were studied in order to understand the environmental conditions responsible for the deterioration observed at the edges. Leaching from the treatment was identified as being partly responsible for the decrease in mechanical performance measured at the edge of the structure. Mineralogical transformations, such as the formation of calcite in the first few metres of the backfill, also highlighted an alteration of the hydromechanical behaviour through carbonation of the cement phases. The role of wetting and drying periods in the mechanical weathering of the treated soil was also studied. Specimens from the inner part of the structure were subjected to wetting and drying cycles of various suctions ranging from 0 to 95 MPa. The results showed that drying and wetting cycles have a major impact on the long-term performance of treated soils above a certain suction amplitude. The degradation process is mainly a consequence of cement bond failure rather than other physico-chemical processes such as calcium leaching or carbonation. This study allowed a mechanical quantification of the weathering of treated clay taken from an experimental structure. Leaching and carbonation during treatment were identified as being responsible for the deterioration in mechanical performance in the external part of the structure. The study of the treated material subjected to hydric cycles allowed to quantify their impact on mechanical behaviour, while determining the mechanisms by which the effects of the treatment were altered
Amar, Mouhamadou Al Amine. "Traitement des sédiments de dragage pour une valorisation dans les matrices cimentaires". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10154/document.
In France, construction sector annual needings for granular materials are close to 400 million tonnes, of which 96% are natural origin. Therefore it becames highly necessary to find alternatives solutions, in particular by valorisation of industrial by-products (IBP) such as dredging sediments. Marine sediments are designated as a secondary raw material in this study. However, the latter may present some levels of pollution, with the presence of organic matter (5% to 30%), relatively high water content (50% to 200%) and a fairly fine granulometry (≤ 300 µm). Currently, research target to use them as a supplementary mineral addition in concrete after efficient methods of treatment that improve some physico-chemical properties. The aim of this this study is to establish a profitable methodology for the use of sediments in cementitious matrix. We first lead a bibliographical review on this subject. At the experimental level, a physico-chemical characterization was carried out, determining the major parameters to be considered, the effects of the treatment on material properties, the likely impact of the presence of sediments in the cementitious matrix, and an experimental methodology to quantify these various effects. The cementitious materials formulated will be analysed and characterized at four scales: physico-chemical, mechanical, durability and the environmental impact. An analysis of the mechanical results makes possible to assess the activity of this material and to implement adapted formulation laws
Li, Mengya. "Caractérisation expérimentale et modélisation du panneau composite bois-ciment". Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0302/document.
Lightweight concretes made from wood fibres and Portland cement paste are a new alternative for the reduction of the environmental impact of buildings. They are used in sustainable constructions as secondary elements for their thermal, hydric and mechanical performance. However, the generalisation of their use is not possible without resolving certain scientific obstacles related to their characterisation. Hence the aim of the present work, which is to contribute towards their characterisation through experimentation and numerical simulation. The Young's modulus and tensile strength were measured through flexural and compression tests. A numerical model has also been developed to predict the behaviour of specimens under bending test as well as their structural response when used as permanent formwork. In particular, the model helps to choose the optimum parameters for a better design of the formwork system. The study of the hygrothermal behaviour of the wood-cement material was carried out using both experimental work and simulation. The equations of coupled heat and moisture transfers for a porous medium have been implemented in the Comsol Multiphysics® software. The developed model has been applied and validated on several dynamic responses resulting from hygro-thermal tests carried out in the laboratory. The obtained physico-thermal properties of the wood-cement composite material were then incorporated into the Abaqus code via a Umatht user subroutine to simulate its high temperature behavior. The temperature profiles are evaluated and compared with the charring tests performed using a radiant panel on samples exposed to a uniform heat flux of 6kW/m². The simulations show that the developed model is able to predict the temperature profiles, the area and the depth of the charred layer during fire exposure
Wassermann, Alice. "Quantification multi-échelles de la dégradation d’un sable traité soumis à des cycles hydriques". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0085.
Soil treatment, especially with hydraulic binders or lime, is a widespread technique to improve the mechanical characteristics of poor-quality soils. After their construction, engineering structures are subjected to environmental solicitations that can potentially alter the effects of the treatment, and thus lead to the degradation of the performance of the treated soil. In this context, the objective of this thesis was to study the impact of the accumulation of hydric cycles on the mechanical behaviour of a cement-treated sand. A multi-scale and multi-physics methodology was set up to understand and quantify the degradation of the macroscopic mechanical behavior of cement-treated sands during drying/wetting cycles.Short-term mechanical characterization of the sand was performed by conducting a triaxial testing campaign. The bonding ratio, η_bondmax, defined according to the stress-dilatancy theory, was introduced to assess the mobilization and the degradation of cementitious bonds during the triaxial tests. In order to characterize the durability of the treated sand, the impact of two types of hydric cycles of different intensity was evaluated. Following the cycles, triaxial tests were performed constituting a database of 130 test results. The bonding ratio monitoring allowed to explicitly quantify the degradation of the cemented specimens as a function of the type and number of cycles. The main effect of the hydric cycles is to alter the cementitious bonds and subsequently to decrease the mechanical performances. This alteration depends on the cement content but also on the intensity of the cycles. Type I cycles lead to a more important degradation than type II cycles. The kinetics of the alteration as well as its extent depend on the cement content.The investigation of the processes occurring at the microscopic scale after 24 cycles of the two types via microscopic observations (SEM and TEM) and physicochemical analyses (XRD and GTA) has highlighted intense mineralogical transformations including carbonation of the cementitious phases to various degrees depending on the intensity of the cycle as well as the formation of ettringite needles in the pore-space. However, in terms of macromechanical behaviour, a stabilization of mechanical performance after a moderate decrease (-20 to -30% of the deviatoric stress) was observed after 12 hydric cycles. This approach has shown that relating mineralogical transformations to durability is not sufficient. It is necessary to evaluate the contribution of each phase to the strength since intense mineralogical transformations are not necessarily associated with strong degradation of the treated soils.A constitutive law to model the observed deviatoric behaviour of treated sand was proposed by combining the Hardening Soil Model for the pre-peak hardening and an inverse sigmoid function for the post-peak softening. This approach showed a satisfactory accuracy to simulate the behaviour and in particular the softening of treated soils under relatively high confining pressures. Under low confining pressures an exponentially decreasing function was however more suitable. In addition, parameters optimization determined the most appropriate values for 5 model parameters (ψ, Rf, m, λ, and ecrit) as a function of cement content. The modeling permitted to complete the experimental study and broughtsome reflexions on the way to simulate the post-peak behaviour.This study allowed a mechanical quantification from macroscopic observations coupled with a physicochemical quantification of the various processes occurring during hydric cycles. A conceptual framework allowing to take into account the effect of cementing in the behaviour of treated soils was proposed
Houget, Véronique. "Etude des caractéristiques mécaniques et physico-chimiques de composites ciments-fibres organiques". Lyon, INSA, 1992. http://www.theses.fr/1992ISAL0065.
This work deals with the study of the mechanical properties of organic fibres reinforced cementitious composites and the microstructural analysis of fibres-rnatrix interfaces. Seven fibres were chosen : polyamide, polyacrylonitrile, polyester, polypropylene, polyvinylalcohol, polyaramid and carbon. The reinforcement ratios varied from 0. 35 to 6% by weight. The results obtained from the study of some continuous fibres reinforced cementitious composites show a certain adhesion fibres and matrix witch can be assessed from "reinforced concrete" modelling. When short fibres are used, the portlandite is the main hydrate at fibre-matrix interface. It reacts with polyester fibres and leads to a brittle composite with time. In other cases, it prevents fibres from slipping and reduces the composite ductility (polyvinylalcohol, polyacrylonitrile). For polyamide and polypropylene fibres, the ductility is preserved. With polyaramid and carbon, brittle composites are obtained
Verron, Heloïse. "Étude expérimentale des interactions matériau cimento-bentonitique / argilite / fer et acier (MREA/COx/Fe ou acier) à 90°C en conditions de stockage géologique profond des déchets radioactifs (CIGEO)". Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0205.
In the current concept of radioactive waste deep geological disposal planned by Andra (CIGEO project), waste containers are stored into disposal cells drilled into the Callovo-Oxfordian claystone (COx) and encircled by a carbon steel liner. COx and in particular its pyrites, can be oxidized during the drilling of cells. Thanks to an original experimental set-up, involving several pyrite/mineral mixtures and a reactor coupled to a micro gas chromatograph, it is demonstrated, based on the measured O2 consumption that at 100°C in presence of calcite, less than 50% of the pyrite is oxidized. This oxidation induces a transient acidic plume and consequently the corrosion of the steel liner. Andra has developed and patented a low-pH (9
Lahbabi, Mohammed. "Contribution à la physico-chimie de matériaux calciques : Réactivité des gypses résiduaires et leur intérêt dans l'élaboration de nouveaux ciments sulfatés, structure et magnétisme dans les ferrites de calcium CaFe3O5 et CaFe4O6". Nancy 1, 1989. http://www.theses.fr/1989NAN10516.