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Daher, Suzanne. "Optimisation de la formulation d'un béton de chanvre : effet des interactions physico-chimiques entre les particules végétales et le liant". Electronic Thesis or Diss., Amiens, 2022. http://www.theses.fr/2022AMIE0041.
Pełny tekst źródłaHemp concrete is one of the most popular bio-based building materials in France. It is often used as a filling and / or insulation material, in an eco-construction system. Given its high porosity, this concrete has particularly advantageous thermal and hygric performance. However, the lighter this hemp concrete, the higher its level of thermal insulation, while its mechanical properties decrease. This is why it is necessary to optimize its formulation, in order to obtain the best compromise between its mechanical, hygric and thermal performance, depending on the field of use (carrier and / or insulator). The first optimization approach considered consists in varying the rate of plant aggregates in the composition of the concrete, but also the nature and quantity of binder used. The objective of this thesis is to study the mechanical, thermal and hygric properties of a hemp concrete according to its formulation. In this thesis, we are interested in the feasibility of lightweight building materials based on hemp particles and a lime-based binder, which present good mechanical performances. The main objective is to overcome the migration process of free Ca2+ to the lumen of hemp particles that are responsible for their degradation and which, consequently, induce the loss of mechanical performance of the final composite material. To achieve this, a fraction of the base binder is replaced by metakaolin. First, we studied the influence of different percentages of metakaolin on the carbonation of two lime-based control mortars: NHL5 lime and Tradical PF70 pre-formulated lime. Then, we measured their mechanical resistances in compression and flexion in order to define an optimal formulation. Thus, the finished composite materials are tested for different volume percentages (2v and 3v) of hemp particles. The results of the characterization of the physico-mechanical properties of the specimens are presented and argued. A close relationship between the metakaolin content and the physico-mechanical properties of the hemp concrete has been observed, due to the additional hydration products derived from pozzolanic reaction mechanism. The MEB and EDX analyses have shown the enhancement of hemp particles-binder Interfacial Zone Transition, while the pozzolanic reaction leads to reduce the migration process of free Ca2+ to lumen of vegetable particles thus reducing their mineralization. Then, we compared the hygro-thermal performances of hemp concretes formulated with respectively 2 volumes and 3 volumes of plant particles for one volume of binder, without or with 20% metakaolin, the optimal percentage defined previously. This study is particularly useful to establish the adequate proportions of admixtures to be used in concretes intended for renovation works or new constructions. Generally speaking, and depending on the formulation, we obtain a material that is a good or even excellent regulator of ambient humidity, with interesting thermal performances for the insulation of buildings. This characterization work completes the many works already carried out on biobased concrete with different types of plants, and should make it possible to feed the databases essential for the simulation of the behavior of a wall or of the envelope of a building under different climates and guarantee the comfort of the occupants
Fontaine, Florian. "Composites à matrice carbone-oxyde et carbone-nitrure : thermodynamique de l'élaboration et son impact sur les propriétés physico-chimiques, thermiques et mécaniques des composites". Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14217/document.
Pełny tekst źródłaCarbon/carbon composites exhibit excellent mechanical and thermal properties at high temperature that make them espe-cially suitable for ablation or friction pieces. Their sensitivity toward oxidation above 400°C has lead to the will of doping them with refractory ceramics that are nonoxidizable or with a high oxidation temperature. The sol-gel process allowed to introduce 1 % in volume of titanium or aluminum oxide or nitride in the matrix. Nitrides are obtained by carbothermal nitridation of the oxide films. Two types of sols were used: the “standard” ones and those with extra sucrose. Sucrose is added to prevent pyrocarbon consumption during the nitridation. Furthermore, it was shown that it has an impact on the nitridation rate. Charged composites are then densified by Chemical Vapor Infiltration, which induces phases transforma-tions that were predicted by thermodynamics: titanium nitride films are partially carburized (formation of titanium carbonitride) and titanium dioxide films are reduced (formation of titanium oxycarbide). Aluminum-based films are more stable and don’t undergo any transformation. Thermal diffusivity of the as-synthesized composites is not much modified by the addition of these ceramics while the tensile and compressive strength are slightly increased. By the way, composites are hardened. Their oxidation kinetics is slowed down. Aluminum-rich composites exhibit a weight loss divided by two compared to the C/C reference. All those properties are directly, or not, linked to the composition of the sols, in particular to their sucrose content. Indeed, it was shown that sucrose-containing sols rather jellify on the surface of the composite, thus preventing the diffusion of precursor gases to the heart of the pieces. The final porosity is then modified. The porosity has an important impact on the compressive strength, thermal diffusivity and oxidation kinetics of the synthesized composites
Bohnke, Isabelle. "Etude expérimentale et théorique des traitements thermiques du bois. Caractérisation physico-mécanique des bois traités". Paris, ENMP, 1993. http://tel.archives-ouvertes.fr/tel-00844044.
Pełny tekst źródłaBasrour, Skandar. "Contribution à l'étude des propriétés physico-chimiques et électroniques des alliages amorphes de SiGe:H déposés par PECVD". Grenoble 1, 1990. http://www.theses.fr/1990GRE10072.
Pełny tekst źródłaKhay, Ismail. "Etude physico-chimique des interfaces chaux/chanvre/argile : Impact sur la rhéologie des mortiers et sur les propriétés mécaniques, thermiques et hydriques du matériau composite". Limoges, 2012. http://aurore.unilim.fr/theses/nxfile/default/03feab96-e977-420f-b23c-f2c8dec95df3/blobholder:0/2012LIMO4055.pdf.
Pełny tekst źródłaUnderstanding the different physical and chemical phenomena involved during the formulation and shaping processes for a composite material made of a mineral matrix and cellulose fibers, leads to a better optimization of the elaboration and the final consolidation, and also to establish the correlations between the microstructures and the physical properties of the composites. The rheological behavior of studied mortar depends on the pH of medium, the nature and the specific surface area of clay minerals. When calcined clay mineral is present, it provides a pozzolanic effect to the mixture and participates in the stabilization of the composite material. Adding fibers to mineral matrix modifies the fragile character of the mineral matrix to a nonlinear endommageable behavior, which is characteristic of a composite material. A treatment of fibers with sodium hydroxide allows to individualize microfibrils: it increases the fibers roughness, indicating a reduced interface between the fibers and the matrix. However, these microfibrils are very sensitive to water. Addition of hemp fibers decreases the thermal conductivity of the composite. These cellulosic fibers present significant hygroscopic properties, resulting in a change of water absorption by capillarity. So, these composite materials are resistant to freeze / thaw cycles
Sani, Rababe. "Étude des transformations microstructurales de mélanges argile/Combustibles Solides de Récupération (CSR) lors de la cuisson : relations entre propriétés physico-chimiques, mécaniques et thermiques". Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0005/document.
Pełny tekst źródłaThe valorization of co-products rich in organic and inorganic materials as additives in formulations based on clay matrix can improve both the mechanical and thermal performances of ceramic materials as well as the energy balance of the manufacturing processes of these products. This study focused on the incorporation of Solid Recovered Fuels (SRF) into the clay ceramics for civil engineering in close collaboration with TERREAL as part of the ANR funded LabCom RESPECTc project. Firstly, two SRF were selected and used as additives to improve the properties of ceramic materials from to clay mixture deposits named ML and MC from TERREAL. The influence of the nature, the amount of SRF, the grain size of SRF and the nature of clay matrix on the physico-chemical, mechanical and thermal properties of the clay/SRF mixtures were studied between 30°C and 1100°C. In all cases, the addition of SRF into the clay mixture (ML or MC) has enhanced the insulating nature of the ceramic materials by reducing their thermal conductivity. The addition of SRF has also improved the mechanical properties of the ceramic materials, depending on the nature and the amount of SRF added, the rate and the nature (shape, size and distribution) of the porosity created. The study demonstrated that interactions between clay minerals and inorganic elements of SRF have a significant effect on mechanical and thermal properties. The results showed that the addition of 4 wt.% of SRF15-1 containing an ash content of 65.7 wt.% into clay matrix ML led to increase the mechanical strength of the material based on the clay matrix ML of the order of 32%. Then, a kinetic model of thermal sintering based on the dimensional variations of ceramic materials between 650°C and 1000°C was developed from thermomechanical analysis (TMA) of the clay mixtures (with or without SRF). The main objective is to better understand the mechanism of the thermal sintering involved. The model developed showed a good adequacy with the experimental data. The results showed that the thermal sintering step of these mixtures is carried out by the presence of a liquid phase and that the addition of SRF has accelerated the densification of ceramic materials. This has led to decrease the usual firing temperature of ceramic materials, allowing a significant energy savings. Finally, an environmental assessment was carried out during the firing of clay/SRF mixtures. This study was particularly focused on the contribution of SRF to the energy balance and impact of critical gas emissions such as CO2, CO and HCl. The results showed that CO2 and CO emissions during firing of clay/SRF mixtures increased due to the thermal decomposition of the organic matter of SRF and that less than 50 wt.% of chlorine was converted to HCl (18-31 ppm). The energy balance showed that the addition of SRF into the ML matrix compensates for a significant part of the natural gas usually used as fuel during firing of these ceramic materials. This was reflected by a thermal energy saving and reduction of CO2 emissions from the decarbonatation of the clay matrix
Bohnke, Isabelle. "Étude expérimentale et théorique des traitements thermiques du bois. Caractérisation physico-mécanique des bois traités". Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 1993. http://tel.archives-ouvertes.fr/tel-00844044.
Pełny tekst źródłaSani, Rababe. "Étude des transformations microstructurales de mélanges argile/Combustibles Solides de Récupération (CSR) lors de la cuisson : relations entre propriétés physico-chimiques, mécaniques et thermiques". Electronic Thesis or Diss., Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0005.
Pełny tekst źródłaThe valorization of co-products rich in organic and inorganic materials as additives in formulations based on clay matrix can improve both the mechanical and thermal performances of ceramic materials as well as the energy balance of the manufacturing processes of these products. This study focused on the incorporation of Solid Recovered Fuels (SRF) into the clay ceramics for civil engineering in close collaboration with TERREAL as part of the ANR funded LabCom RESPECTc project. Firstly, two SRF were selected and used as additives to improve the properties of ceramic materials from to clay mixture deposits named ML and MC from TERREAL. The influence of the nature, the amount of SRF, the grain size of SRF and the nature of clay matrix on the physico-chemical, mechanical and thermal properties of the clay/SRF mixtures were studied between 30°C and 1100°C. In all cases, the addition of SRF into the clay mixture (ML or MC) has enhanced the insulating nature of the ceramic materials by reducing their thermal conductivity. The addition of SRF has also improved the mechanical properties of the ceramic materials, depending on the nature and the amount of SRF added, the rate and the nature (shape, size and distribution) of the porosity created. The study demonstrated that interactions between clay minerals and inorganic elements of SRF have a significant effect on mechanical and thermal properties. The results showed that the addition of 4 wt.% of SRF15-1 containing an ash content of 65.7 wt.% into clay matrix ML led to increase the mechanical strength of the material based on the clay matrix ML of the order of 32%. Then, a kinetic model of thermal sintering based on the dimensional variations of ceramic materials between 650°C and 1000°C was developed from thermomechanical analysis (TMA) of the clay mixtures (with or without SRF). The main objective is to better understand the mechanism of the thermal sintering involved. The model developed showed a good adequacy with the experimental data. The results showed that the thermal sintering step of these mixtures is carried out by the presence of a liquid phase and that the addition of SRF has accelerated the densification of ceramic materials. This has led to decrease the usual firing temperature of ceramic materials, allowing a significant energy savings. Finally, an environmental assessment was carried out during the firing of clay/SRF mixtures. This study was particularly focused on the contribution of SRF to the energy balance and impact of critical gas emissions such as CO2, CO and HCl. The results showed that CO2 and CO emissions during firing of clay/SRF mixtures increased due to the thermal decomposition of the organic matter of SRF and that less than 50 wt.% of chlorine was converted to HCl (18-31 ppm). The energy balance showed that the addition of SRF into the ML matrix compensates for a significant part of the natural gas usually used as fuel during firing of these ceramic materials. This was reflected by a thermal energy saving and reduction of CO2 emissions from the decarbonatation of the clay matrix
Pan, Jing. "Effet de la température et de l'agitation sur les propriétés rhéologiques des bétons fluides à rhéologie adaptée". Thèse, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/7567.
Pełny tekst źródłaAbstract : The local climate, the transport of agitated concrete after manufacturing but before being cast strongly influence the properties of the fresh and hard concrete. It’s important to keep the stability and workability of the self-consolidating concrete (SCC) because of its special characteristics. Compare to the normal concrete, the properties of SCC are generally more sensitive to the temperature and the transport. Therefore it’s necessary to understand the effects of the temperature and the agitation on the performance of the SCC in order to predict the consequences of climate change (temperature) and transport (time and speed of agitation), and then to give the better precautions with a good performance-cost report. In this study, the concrete mortar equivalent (CEM) method is used to quickly analyze the influences of the temperature and the agitation on the rheological, calorimetric and mechanical properties of the SCCs. Five temperatures (8, 15, 22, 29 and 36°C) and two agitation speed (6 and 18 tr/min) are varied in CEMs. And then, some compositions (type of adjuvant and supplementary cementing material) are chosen to be valued with the temperature (8-36°C) and the agitation (2 and 6 tr/min) in SCCs for the building without air-entraining admixture (AEA) and semi-flowable SCC for infrastructure with AEA. The initial slump flow of CEM and SCC is fixed, but the demand superplasticizer, the temperature and the agitation were varied. The results show that there are the effects of temperature and agitation on the effectiveness of admixture, the slump flow, the air content, the rheological, calorimetric and mechanical properties of CEM and SCC. A mathematical equation is proposed to predict the performance of SCC at different temperatures for the SP and AEA requirement, the maximum of heat flow and the compressive strength at one day by these same properties of SCC at 22°C and by the temperature. Finally, a good linear correlation is found between CEM and SCC for these properties.
Thai, Khac Chien. "Etude de l'endommagement de l'interface acier-béton à l'aide de techniques non-destructives : Comportement sous sollicitations mécaniques, thermiques et physico-chimiques". Thesis, Rennes, INSA, 2013. http://www.theses.fr/2013ISAR0012/document.
Pełny tekst źródłaReinforced concrete combines the good tensile strength of steel with the high compressive strength of concrete. However, this association is of real interest if there is a good adhesion at the interface of the two components (concrete and reinforcement). However, accidental or environmental attack may alter the adhesion and make it impossibleto transfer forces between the two components. The aim of this dissertation is to study the properties of the steel concrete interface and to characterize its damage due to mechanical, thermal, and the physicochemical attacks. The main demands included in this study concern the effect of high temperatures, the effect of carbonation, the effect of alternating freeze / thaw and the effect of corrosion. In this study, we used different non-destructive techniques for the material characterization and we have developed original devices for simultaneous measurements of the pull-out resistance and for evaluation of discontinuities. Among the influencing parameters of adhesion, we examined the effect of the nature of the steel bars (smooth bar or deformed bar), the effect of their diameter and of the embedment length. The results highlight the respective interventions of the physicochemical bonding, the mechanical friction and the effect of the concrete strength in thefailure mode of reinforced concrete specimens. The different phases of interface degradation have been identified
Marc, Teodor paul. "Conception et réalisation de structures routières à hautes performances". Thesis, Artois, 2011. http://www.theses.fr/2011ARTO0214/document.
Pełny tekst źródłaThe doctoral thesis analyses certain factors of influence that, through large temperature variations, frequently have a negative impact upon road pavements, especially the bituminous layers, with a view to determine the thermal-physical properties (thermal conductivity, specific heat, diffusive thermal, thermal effusion and emissivity) and to design and realize asphalt layers with better thermo-physical, and physical and mechanical characteristics.Practically, the studies highlighted in the thesis focus mostly on determining the thermal characteristics of asphalt mixtures, characteristics which help to combat the influence factors resulting from environmental conditions to which road structures are subject continuously road in the construction and repair stages, as well as during their service life. Due to being aware of temperature distribution in each bituminous layer of the road structure, the stresses occurring from variations of temperature can be controlled. The daily and seasonal fluctuations of air temperature, the intensity of solar radiation, the materials that make up the road structure layers by their geometry and surface conditions are some of the most important factors that significantly endanger the stability of the road structure.Positive contributions have been made on improving the thermal characteristics through designing and realizing asphalt mixtures in the composition of which, in addition to basic materials, flying ash was used as partial or total replacement for filler. This helps to obtain higher thermo-physical properties that have a favorable effect on physical and mechanical characteristics.Based on experimental results, some interesting and in the same time extremely valuable conclusions have been formulated opening a range of opportunities for further research in the field of road infrastructures
El, Fgaier Faycal. "Conception, production et qualification des briques en terre cuite et en terre crue". Thesis, Ecole centrale de Lille, 2013. http://www.theses.fr/2013ECLI0023/document.
Pełny tekst źródłaNowadays, the reduction of energy consumption in buildings industry represents a major issue in industrialized countries’ policies. In France, the building sector consumes about 43% of final energy and accounts for nearly a quarter of the national emissions of greenhouse gas emissions [ADEME]. It is considered as a key factor to overcome the environmental challenges we have to face.In front of these significant challenges, the thermal regulations requirements were seriously intensified during the last 40 years until the notification of the thermal regulation 2012. This latter enable the construction of low energy buildings (BBC) whose consumption is equivalent to 50 kWh/m² per year on average. This new regulation provides a strong incentive for innovation of materials, products and envelope systems. Under these conditions, improving hygrothermal performance of building materials will allow a substantial economic and environmental benefits. This work was conducted in this context. It aims to study and improve the performance of the company Briqueteries du Nord (BdN) products. It is divided in two main axis: the first consists on studying the thermal inertia and hygroscopic capacity of unfired clay bricks. However, the second axis aims to develop possible solutions for improving the thermal resistance of fired clay bricks. This research was conducted in the laboratory of the Ecole Centrale de Lille with close collaboration with the University of Artois and the BdN company
Bour, Yves. "Matériaux composites à fibres courtes : Relation entre facteur d'orientation et propriétés mécaniques et thermiques". Metz, 1999. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1999/Bour.Yves.SMZ9906.pdf.
Pełny tekst źródłaThe behavior of short fibers composite materials depends strongly of the orientation of the fibers. Using magnetic fields, anisotropic composite materials have been elaborated which contained up to 20 vol% of carbon fibers. One aim was to gain a better understanding of the process of orientation in the magnetic field. A model has been formulated to describe the movement of a single fiber which is exposed to a static and an oscillating magnetic field. Other parameters such as viscosity of the liquid polymer, temperature and fiber length were examined as well. The degree of anisotropy of the materials is measured by microscopy coupled to an optical imaging system, this work leading to define a procedure of filtering the image in order to obtain precisely the fiber orientation distribution (function). As well as the thermal conductivity was measured which is related to the three-dimensional orientation. The results from optical and thermal measurements correlate well, but the theoretical models to interpret the thermal conductivity are not yet reliable enough to allow the degree of orientation to be reduced from the measurements. Regarding the mechanical properties the increase of the YOUNG's modulus was measured and correlated with the fiber orientation distribution. Between the mechanical models tested some are found to agree well with the experiments
MALOU, ZAHIR. "Etude de l'optimisation des proprietes mecaniques et thermiques des materiaux poreux de type betons cellulaires". Cergy-Pontoise, 1996. http://www.theses.fr/1996CERG0013.
Pełny tekst źródłaPerez-Perez, Maria-Cristina. "Structure et propriétés mécaniques et de transfert des films comestibles à base de caséinate de sodium". Vandoeuvre-les-Nancy, INPL, 2001. http://docnum.univ-lorraine.fr/public/INPL_T_2001_PEREZ_PEREZ_M_C.pdf.
Pełny tekst źródłaAdlani, Ahmed El. "Contribution à l'étude des transformations physico-chimiques de bitumes français et américains". Lille 1, 1993. http://www.theses.fr/1993LIL10129.
Pełny tekst źródłaBourret, Julie. "Élaboration de céramiques alvéolaires à base de kaolin : propriétés thermiques et mécaniques". Limoges, 2012. https://aurore.unilim.fr/theses/nxfile/default/feab8bd8-27be-4c21-839a-aaaa32034cba/blobholder:0/2012LIMO4058.pdf.
Pełny tekst źródłaCandidate materials for thermal insulation combine a solid phase of low thermal conductivity (<1 W. M⁻¹. K⁻¹) with a high pore volume fraction. This work concerns the preparation of ceramic foams exhibiting such characteristics using kaolin clay as the starting material. Processing involves a surfactant to stabilize the foam while remaining low cost and environmentally friendly. The properties of a clay-based material are sensitive to the orientation of the clay particles and, with thermal treatment, mineralogical transformations. Measurements of thermal conductivity and Young's modulus were made on textured kaolonite/muscovite samples obtained by extrusion, uniaxial or isostatic pressing and cut in different directions. An initial study revealed anisotropy at the macroscopic scale up to a factor of 3 related to the forming conditions and the amount of muscovite. However, with thermal treatment, this factor is progressively removed by transformations such as dehydroxylation and formation of mullite. In the last part, the pore volume fraction (Vp) was varied in the kaolin based foam by modifying the incorporated clay amount in the starting mixture. After thermal treatment at 1100̊ C, measurements of the thermal conductivity revealed a decrease from 0. 23 W. M⁻¹. K⁻¹ at Vp=0. 57 to 0. 054 W. M⁻¹. K⁻¹ at Vp=0. 95 in close agreement to predictions by the Hashin-Shtrikman upper bound, a cubic pore model and numerical simulation. The effective Young's modulus, obtained from mechanical compression tests, also decreases with pore volume fraction as described by Ashby's relation. However, the mechanical strengh was sufficient for handling even the more porous kaolin based foams
Mohaine, Siyimane. "Etude des propriétés thermiques et mécaniques des bétons isolants structurels incorporant des cénosphères". Thesis, Ecole centrale de Nantes, 2018. http://www.theses.fr/2018ECDN0030/document.
Pełny tekst źródłaIn the field of building thermal insulation, regulatory (RT2012) and standards (NF BPE: Béton à Propriétés Thermiques, September 2016) evolutions are encouraging the use of insulating structural concrete (BIS). The control of their thermal conductivity is essential. It is possible, in addition to using lightweight aggregates, to modify the composition of the cement paste by using hollow inclusions (fly ash cenospheres) to bring an additional thermal insulating potential. In a context of improved workability, to these properties is added the criterion of self-compacting concrete. The validation of these new formulas required the characterization of materials at different scales (from inclusion scale to building scale) by implementing experimental and numerical approaches. Their properties at fresh and hardened state were analyzed. The measured thermal conductivities place these new concretes in the Category of Structural Insulating Concrete in the sense of the new standard. The developed numerical model allowed approaching the experimental measurements correctly. The effect of cenospheres’ incorporation into cement paste on several durability indicators was also characterized
Betene, Ebanda Fabien. "Etude des propriétés mécaniques et thermiques du plâtre renforcé de fibres végétales tropicales". Thesis, Clermont-Ferrand 2, 2012. http://www.theses.fr/2012CLF22298/document.
Pełny tekst źródłaThe plaster is a material of high availability and very known for its qualities : it is favourable to the protection of the environment, quite malleable, of low density, its functional properties are remarkable (firewall, thermal insulation, regulator of the hygroscopy of enclosures), decorative, ... What justifies the interest attached to this material for constructions. Its great alarming brittleness is at the origin of the research tasks in the whole world for its strengthening. The glass fibers and sisal are the more used reinforcements to this day. The strengthening by plant fibers is more and more researched. The microstructure of the plaster is porous ; that promotes its heat insulation character. The textures implemented so far are limited to porosities ranging between 30 and 55%. The reduction of cost of this material for a wide use is still possible and desired. Two levers are exploited in this work, in particular a lightening of the plaster weight to increase the proportion of air voids and a reinforcement of the mechanical resistance with locally produced fibers. The objective of this work is to evaluate the mechanical, thermal and hygrometrical characteristics of a material made up of harden plaster, with high porosity, strengthened by a new plant fiber : the Rhecktophyllum Camerunense (RC), a fiber of humid equatorial forests. The sisal fiber, of known use for the strengthening of the plaster, serves as a reference for comparison purposes. A serie of experiments is conducted to this effect. A physicochemical characterization of constituents is performed. Mechanical tests of tensile and of bending are performed on the constituents and the resulting plaster/fiber composite materials. The kinetic adsorption of moisture by the constituents is followed. The thermal behaviour of plaster and plaster/fiber is also measured. The fibers used, sisal and RC are with high rates of cellulose (between 49 and 78.8% ), the fiber of RC is tubular with 35.5 % of porosity. The plaster is dissolved in demineralized water to a mass ratio W/P equals to 1 from the powder of semihydrate β. Its crystalline microstructure is composed of gypsum crystals in the form of needles tangled with the empty intercristallins. As far as the mechanical behavior is concerne, the result reveals that the plaster is weak, its Young’s modulus in tensile is 1.72 GPa, its tensile strength is 0.86 MPa and its elongation at break is 1.16 %. In three points bending test, its modulus of elasticity is 0.64 GPa and its constraint at break is 0.13 MPa. The sisal fiber is stiff and fragile. Its Young’s modulus is between 9 and 21 GPa, it admits an elongation at break of 3 to 7 %. On the other side, the fiber of RC is quite ductile : the means of Young’s module is 7 GPa and the elongation at break is 24.2 %. The adhesion of the plaster on the fiber surface is low : it adheres more on the sisal than on the RC. The sisal strengthened better the plaster with a sensitive increase of the Young’s modulus of 42.5 %, against 16.3 % for the RC. But the RC fiber gives rather high elastic ductility. The fibers of RC deliver maximum capacity in tensile to the plaster when they are woven into unidirectional. They offer high capacity in bending when they are uniformly distributed inside the volume according to the longitudinal direction of the structure. (...)
Imbert, Claire. "Matériaux à propriétés mécaniques et thermiques améliorées sous pression hydrostatique en utilisation aquatique". Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20019.
Pełny tekst źródłaMaterials nowadays used for thermal insulation in aquatic environment under hydrostatic pressure are either rubber flexible foams or rigid foams, especially syntactic foams, depending on depth. These flexible materials were analyzed through classical mechanical and thermal tests. However, methods and results were adapted to the final usage of the product, particularly to the aquatic environment at the surface and under depth. Relationships between structures and properties characteristics were studied to define appropriate properties within relevant criteria. Moreover, to underline thermal properties under hydrostatic pressure, a testing instrument has been developed: an innovating hyperbaric test chamber, dedicated to under water pressure thermal resistance and thickness measurements, from 0 to 50 m depth. Strengths and weak points of these classical materials have been clearly established. Results analysis lead to a new concept of composite material for the defined usage. This innovating material, a syntactic foam, has been developed. By varying the particle type added to a thermoplastic elastomer matrix, the cellular structure has been refined in order to obtain a similar behaviour in aquatic environment, at the surface like in depth. This material has been tested, parallel to its industrial production, to identify relationships between structures and properties
Ezbakhe, Hassan. "Caractéristiques thermiques et mécaniques de matériaux poreux utilisés comme isolants simples ou porteurs". Lyon 1, 1986. http://www.theses.fr/1986LYO10024.
Pełny tekst źródłaTchofo, Dinda Patrice. "Étude d'un réseau bidimensionnel à maille hexagonale à deux sites dans un substrat double-quadratique : diagramme de phase, structure et dynamique des parois, effets de taille finie". Dijon, 1991. http://www.theses.fr/1991DIJOS061.
Pełny tekst źródłaAussedat, Yahia Eve. "Comportement et endommagement du composite tisse Carbone/PMR15 soumis à des chargements mécaniques et thermiques". Paris, ENMP, 1997. http://www.theses.fr/1997ENMP0748.
Pełny tekst źródłaDevaux, Alexandre. "Etude de l'influence des traitements thermomécaniques et thermiques sur la microstructure et la tenue en fluage de l'alliage 718". Paris, ENMP, 2007. http://www.theses.fr/2007ENMP1477.
Pełny tekst źródłaThe aim of this study is to improve the creep properties of Alloy 718 used in turbine discs, without affecting the tensile and fatigue properties obtained with the standard thermomechanical treatment. In this context, an optimized two-stage solution heat treatment has been developed which partly dissolves the intergranular phase without causing the formation of coarse grains which impair fatigue performance. The higher volume fraction of ’’ precipitates improves the yield strength and creep properties over a wide temperature range, and fatigue properties are preserved by the fine-grained microstructure. The study of the direct aged thermomechanical treatment evidenced a creep behavior relatively different from those observed with other thermomechanical treatments, which suggests that different creep mechanisms are at play in the various conditions covered in this study. The different effects on the studied microstructures under greater and lesser stress and temperature variations confirm the presence of these creep mechanisms. This study also focuses on the kinetics of precipitation of the ’’ hardening phase. The study of the influence of the aging stages on ’’ phase precipitation and on the mechanical properties revealed that there are optimum precipitate sizes. This work also enabled us to analyze the creep behavior of Alloy 718 at high temperature by modeling, on the one hand, the influence of microstructural parameters on the minimum secondary creep rate and, on the other hand, the influence of precipitate coarsening during creep testing
Chabi, Edem. "Étude de la formulation et des propriétés mécaniques et thermiques du béton de balles de riz". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0232/document.
Pełny tekst źródłaEveryone agrees today that human activities significantly affect the climate of the planet. The construction sector is one of the main contributors to this situation as it is the largest energy consumer and the second largest CO2 emitter in the world. It is therefore important to build eco-friendly buildings, which consume little energy and emit less greenhouse gases throughout their life cycle. The present study is then integrated into a general problem of development of innovative building materials with reduced environmental impact. We propose to use the rice husk as a vegetable aggregate in a cementitious matrix. The objective of the work is to propose a method for the mix design of concretes based on plant aggregates and to study the mechanical and thermal behavior of rice husk concrete. Setting tests on pure cement paste formulated with water resulting from the infusion of the rice husk showed that these aggregates had no inhibiting effect on the setting of the cement. To confirm this hypothesis, a chemical analysis of the rice husk was carried out and the results showed that the extractable ratio of rice husks is almost zero, unlike other plant aggregates such as hemp and wood. The proposed formulation method consists in determining the packing density of the plant skeleton for a given method of implementation and then in proportioning the binder paste which will occupy the residual intergranular pore volume. The paste is consisted of the binder, the effective water, the possible additions and admixture, and trapped air and/or entrained air. For a given volume of air (and additions), the quantities of cement and effective water are then adjusted to achieve the targeted performances, based on the law of Féret. However, for this type of concrete, the large volume of entrained air also depends on the quantity of cement and water present in the mixture, the intensity of the mixing and the casting mode. A model describing the volume of residual air was then calibrated from tests carried out with the components of the concrete that it is desired to manufacture. Finally, the problem of formulation is solved by using a numerical optimization module. In order to validate the model, the method for the mix design was applied to five samples with a target resistance of 0.5; 1; 2; 4 and 8 MPa. The performances obtained are quite similar to those targeted. In addition, it has been observed that the preservation mode of the specimens has a significant influence on the mechanical strength of the material. Indeed, a cure in desiccation condition can reduce the mechanical resistances up to 60%. The best resistances obtained were observed on the specimens preserved at 95 % RH. Measurements of thermal conductivity have shown that rice husk concrete is a very good alternative to more conventional systems in terms of thermal insulation. The average value of the thermal conductivity of the rice husk concrete varies depending on the binder dosage between 0.070 W/(m.K) and 0.171 W/(m.K). The evolution of the thermal conductivity as a function of the density and the cement dosage is linear
Franbourg, Alain. "Influence d'un traitement à l'état fondu sur la structure cristalline et les propriétés mécaniques du poly(oxymethylène) et du poly(éther éther cétone) : relations : mise en oeuvre par injection/structure/propriétés". Lille 1, 1990. http://www.theses.fr/1990LIL10091.
Pełny tekst źródłaCapsal, Jean-Fabien. "Elaboration et analyse des propriétés physiques de nanocomposites hybrides ferroélectriques". Toulouse 3, 2008. http://thesesups.ups-tlse.fr/835/.
Pełny tekst źródłaThe piezoelectric activity of a hybrid ferroelectric nanocomposite, i. E. Polyamide 11/ Barium Titanate (BT), has been investigated for different loadings of BT particles. The BT volume fraction (phi) was ranging from 0. 024 to 0. 4 with a particle size of 50 nm, 100 nm, 300 nm and 700 nm. The influence of polarization mode on the piezoelectric behaviour has been studied. The magnitude of the poling field used in this study is in the same order of magnitude of the one used for bulk BT i. E. Significantly lower than for piezoelectric polymers. The optimum piezoelectric coefficient is reached when the amorphous phase of the polymeric matrix is in the liquid state i. E. ; for a polarization temperature higher than the glass transition and for time constant allowing macromolecular mobility. The composite piezoelectric activity decreases for particles size lower than 300 nm due to the loss of the tetragonal phase. The nanotexture of these particles has been investigated by TEM and HRTEM. A core shell structure has been observed. An increase of the longitudinal piezoelectric strain coefficient d33 with the raising of BT volume fraction was shown. Contrary to inorganic piezoelectric ceramics, the dielectric permittivity of hybrid composites remains moderate although the piezoelectric voltage coefficient of composites is bigger than ceramics
Cérézo, Véronique. "Propriétés mécaniques, thermiques et acoustiques d'un matériau à base de particules végétales : approche expérimentale et modélisation théorique". Lyon, INSA, 2005. http://theses.insa-lyon.fr/publication/2005ISAL0037/these.pdf.
Pełny tekst źródłaThis thesis deals with the measurement of physical properties (mechanical, thermal, acoustical) of various formulations of concrete containing vegetable particles. Such material is made up with hemp shives mixed with lime binders. Shives are very porous considering the ratio of capillaries. That fact explains that particles are lightweight, sensible to water and they can be highly strained. The ductile binder is a mixed between hydraulic and aerated lime with sometimes a volume of sand. Depending on the binder proportion, three microstructures of concrete are determined. Moreover, this material presents a microscopic porosity (shives) and a macroscopic porosity. These networks are connected. Vegetable concrete presents a ductile behavior. . The maximum stress and the Young modulus are limited as compare to other building materials but the bearable level of strain is rhigh. A theoretical model made with self-consistent method allows to calculate the Young modulus as a function of the mixture proportion and the compactness level. A comparison with experimental measurements shows a good accuracy of the results. Then, the dry thermal conductivity of vegetable concrete is studied. Considering its high sensibility to water, the level of sorption and the impact on thermal conductivity are evaluated. A self-consistent method leads to a model of dry and wet conductivity taking into account the physical properties (proportions, compactness) and the hygrometry. Lastly, the sound absorption of vegetable concrete is measured. The values are high. This first step in the study of the acoustical properties shows a behavior, which can be compared to materials with a double porosity
Bouillonnec, Jonathan. "Elaboration et étude des propriétés mécaniques et thermiques de matériaux constitués de nanotubes de carbone verticalement alignés". Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30228/document.
Pełny tekst źródłaVertically aligned carbon nanotube carpets are potential candidates for applications such as interconnections or thermal interface materials (TIMs). This research work deals with the synthesis of aligned carbon nanotube carpets from the aerosol assisted chemical vapour deposition (CVD) technique, with the elaboration of nanocomposites made of different grades of epoxy matrix infiltrated within these carpets, as well as the study of both longitudinal and transverse mechanical and thermal properties of dry carpets themselves and 1D-nanocomposites separately. The synthesis conditions notably enable to vary characteristics of the differents carpets such as their thickness, their density, the mean external diameter of the carbon nanotubes (CNT), the intertube space and the CNT volume fraction, whereas their crystalline structure can be modified with a high temperature thermal treatment. The main goal of this work is to prove and quantify the effect of some of the characteristics of the carbon nanotubes carpets on both mechanical and thermal properties of the different kinds of CNT carpets and resulting composite materials. The two impregnation methods used, liquid way and infusion, lead to dense CNT carpets with a preserved alignment of the CNT and an homogeneous distribution of these latest within the epoxy system. The CNT volume content is evidenced as the key-parameter exacerbating the mechanical and thermal properties mainly in the longitudinal direction compared with the alignment axis of the CNTs. Moreover the mechanical and thermal conduction properties of the CNT carpets and the 1D-nanocomposites are clearly increased when the crystalline structure of the CNT is improved. The significant increasing of the properties brought by the vertically aligned CNT within these anisotropic 1D-nanocomposites compared with the only organic matrixes is promising and opens new pathways aiming to meet the latest specifications related to multifunctionnality in fields such as aeronautics and aerospace
Comair, Fadi Georges. "Etude des propriétés thermiques et mécaniques des matériaux de construction : application à l'habitat du Moyen-Orient". Lyon 1, 1989. http://www.theses.fr/1989LYO10077.
Pełny tekst źródłaLallam, Abdelaziz. "Corrélations entre les propriétés thermomécaniques de films diélectriques plastiques et les caractéristiques de composants passifs". Lyon 1, 1985. http://www.theses.fr/1985LYO19054.
Pełny tekst źródłaVerhaeghe, Benjamin. "Allègement de céramiques pour les arts de la table : Influence de la porosité sur les caractéristiques mécaniques et thermiques". Valenciennes, 2010. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/1b47986d-2f67-4418-beb9-e4762561eded.
Pełny tekst źródłaIn this study, porous ceramics are developed and mechanically and thermally characterized. The ceramic matrix is based on a silicoaluminate material then after densified by sintering. The nature of the ceramic material and sintering cycle is unique through all this work. Porosity is obtained by adding to the ceramic paste various organic porous agents calibrated in sizes and shapes. Total porosity rate is between 8 and 30%. Several preparation routes are tested allowing the control of the porosity quality. Heterogeneous porosity is obtained by mixing spray dried siliocaluminate powder with pore-forming agent. The obtained porosities are mainly distributed around the spray dried agglomerates. A relatively homogeneous porosity is provided by an innovative process: A particular porogen agent is introduced within the slurry before spray-drying and leads to specific microstructure consisting in pores (10μm) localized inside the aggregates, while a small amount of porosity remains between them. The mechanical properties (compression, bending, toughness) and thermal properties (thermal diffusivity) are determined and analyzed in regards to porous phases qualities. Meanwhile, various finite element modeling are developed to describe the impact of porosity on the mechanical and thermal properties. Several models of porosity are chosen as close as the experimentally realized porosities. The experimental mechanical and thermal characteristics are compared with modeling results
Nyemeck, André Parfait. "Modélisation de la lubrification mixte et du comportement thermique des garnitures mécaniques". Poitiers, 2011. http://nuxeo.edel.univ-poitiers.fr/nuxeo/site/esupversions/2ece3128-ba75-4399-ac23-1f1d5f66069b.
Pełny tekst źródłaMechanical seals are sealing components used in rotating shafts. They are basically a set of two rings (the rotor and the stator), separated by a lubricant film that must be impervious. The optimum operation is obtained by minimizing both leakage and wear. This corresponds to a film thickness of approximately one micrometer and to a mixed lubrication regime. The literature review justified the choice of a multiscale approach to model a mixed lubrication process. A part of this literature allowed identifying the thermal models to use. A model of a mixed lubrication in mechanical seals based on a multiscale approach is presented. This uses numerical surface roughness and consists in dividing the studied area into sub-domains. The Reynolds equation, which takes into account the fluid cavitation is solved by mean of finite volumes method, at fine scale of the sub-domains, as the hertzian contact asperities. The macroscale is introduced to connect the boundaries conditions of the sub-domains. Then, the macroscale pressure distribution is obtained insuring the mass conservation law. The model also takes into account, at the macroscale step, the Thermo-Elasto-Hydro-Dynamic (TEHD) behaviour in mechanical seals. The discretization of heat and elasticity equations is performed using the finite element method for axisymmetric geometry. The multiscale model is first validated by comparing in to a deterministic model, and then to the TEHD model previously developed at the Pprime laboratory. The influence of the parameters characterizing the mechanical seal behaviour is analyzed through the parametric study. In this study, the different lubrication regimes are identified. The lubricant film thickness is controlled by the roughness or by the thermoelastic deformation of the faces
Gomez, Jean-Paul. "Caractérisation mécanique de composites à matrice d'alliages d'aluminium et renforts particulaires SiC ou Al2O3 (influence des traitements thermiques,études des contraintes résiduelles)". Toulouse, INPT, 1996. http://www.theses.fr/1996INPT032G.
Pełny tekst źródłaNguyen, Thi Thuy Quynh. "Identification des propriétés morphologiques et hygrothermiques hétérogènes de nouveaux composites hautes performances soumis à des cycles de vieillissement thermo-hygro-mécaniques". Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2013. http://tel.archives-ouvertes.fr/tel-00978753.
Pełny tekst źródłaDiascorn, Noémie. "Élaboration et caractérisation d'aérogels superisolants thermiques hybrides à base de silice et de polyuréthane". Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0079/document.
Pełny tekst źródłaAerogels are light and mesoporous materials that appear very promising in terms of thermal insulation. They could play a great part in the future in the reduction of thermal losses through building and appliances envelopes. In this context, the goal of this thesis work is the development of a material combining a very low thermal conductivity and mechanical properties that are compatible with a use in this application sector, via an organic-inorganic hybridization process between a superinsulating - but fragile - silica aerogel, and a very insulating polyurethane aerogel with higher resistance to mechanical stress. In the first part, high performance silica and polyurethane aerogels have each been synthetized via a sol-gel route in mild conditions and in a reaction medium mainly consisting in acetonitrile, then dried in supercritical CO2, and characterized in terms of structure, morphology, texture, thermal conductivity and uniaxial compression. A work on the polyurethane aerogel formulation led to improved thermo-mechanical compromise (thermal conductivity 0.018 W.m-1.K-1, elastic modulus 7.8 MPa) . The mineral and organic matrixes were then coupled, at first in the form of composites (0.018 W.m-1.K-1, 6.1 MPa) based on a dry granular silica aerogel bead. An hybridization process was implemented between the silica and polyurethane phases, that included two successive steps of functionalization of the silica matrix (co-condensation followed by surface grafting and controlled growth of a secondary organic network). The obtained hybrid study was initiated via SEM and XPS analysis and showed a good cohesion at the interface between the polyurethane and the modified silica matrixes
Bouajila, Jalloul. "Etudes physico-chimiques et analyses thermiques de précurseurs de polycondensation obtenus par polymérisation à l'état fondu". Lyon 1, 2002. http://www.theses.fr/2002LYO10092.
Pełny tekst źródłaTriki, Abdelhafid. "Relation entre la démixtion et les propriétés mécaniques d'alliages Fe-Cr concentrés". Grenoble INPG, 1990. http://www.theses.fr/1990INPG0055.
Pełny tekst źródłaObeid, Hassan. "Durabilité de composites à matrice thermoplastique sous chargement hygro-mécanique : étude multi-physique et multi-échelle des relations microstructure-propriétés-états mécaniques". Thesis, Nantes, 2016. http://www.theses.fr/2016NANT4044/document.
Pełny tekst źródłaDue to their excellent specific properties, composite materials with organic matrix are increasingly used in transport industry. During their lifetime, these materials can be subjected to aggressive hygroscopic environments. The moisture especially induces the plasticization of the polymer network, which affects its mechanical behavior, as well as dimensional changes occurring during the diffusion process. The purpose of this work is to experimentally characterize the hygro-mechanical behavior of the studied materials during aging under relative humidity conditions. Numerical analysis methods are implemented in order to identify the evolution of material properties during the transient stage of the process. Among these quantities, the present work consists in characterizing the hygroscopic expansion coefficient and the tensile modulus. It will be established that, in order to appropriately reproduce the experimental, it is necessary to develop a multi-physics and multi-scale approach accounting for the local swelling experienced by the polymer during the transient stage of the moisture diffusion process, as well as the decreasing of the elastic modulus. Moreover, some of the proposed hygromechanical models have been extended to the stochastic framework in order to take into account the experimental uncertainties. The proposed models are implemented in the finite element software Abaqus® enabling to perform numerical simulations leading to predictions of the moisture fields and the internal mechanical states. The proposed approach has been validated with the experimental data and several numerical studies involving neat polyamide resin and composites are proposed
Rajhi, Ramzi. "Calcul des structures en thermo-élasto-plasticité cyclique, fiabilité et sensibilité aux paramètres matériaux". INSA de Rouen, 2005. http://www.theses.fr/2005ISAM0002.
Pełny tekst źródłaGomiero, Philippe. "Microstructure et propriétés mécaniques de l'alliage Al-Li-Cu-Mg(Zr) (2091)". Grenoble INPG, 1990. http://www.theses.fr/1990INPG0129.
Pełny tekst źródłaKarami, Elham. "Effet de traitements thermiques modérés et de revêtement sur les propriétés vibratoires des bois d’Epicéa et de Mûrier". Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT340/document.
Pełny tekst źródłaWood is commonly used for making musical instruments. During the process it is often subjected to treatments, that either modify its volume or its surface properties. Two species used for for string instruments were studied, representative of different cultures: Spruce (Picea abies Karst.) used in Europe and White Mulberry (Morus alba L.) used in Iran. For each of them the effect of thermal treatment at moderate temperature (<150°C) and of coating on various physical and mechanical properties was studied. The main results are as follows. In contrast to Spruce, Morus has a very low degree of mechanical anisotropy. For both species, thermal treatment induces a strong decrease in damping, especially in R direction for Spruce, and equilibrium moisture content, without marked degradation as indicated by the very small weight loss. However, after reconditioning at high humidity, a significant part of the changes is recovered. The application of a solvent-based varnish on Morus induces a continuous stiffening, while a very strong increase in damping after application is followed, after about 2 months, by a return to values close to those of untreated wood. For Spruce, siccative oil based varnish was applied and several parameters of the process were tested. In this case, the kinetics of property stabilisation are very slow and significant changes were still observable after 5 months
Pinault, Mathieu. "Synthèse de nanotubes alignés par CVD d'aérosols : mécanismes de croissance et propriétés physico-chimiques". Paris 11, 2005. http://www.theses.fr/2005PA112109.
Pełny tekst źródłaGuinard, Caroline. "Influence des propriétés morphologiques et mécaniques des barrières thermiques sur la fissuration interfaciale induite par perçage laser impulsionnel". Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEM068/document.
Pełny tekst źródłaMany aircraft engines parts such as combustion chambers are drilled with numerous cooling holes. These holes, generally performed by a high power laser machine can induce damages in the part materials. On thermal barrier coatings systems, cracking can lead to spalling of the coating occurs at the ceramic / bond-coat layer interface during laser drilling. This thesis presents elements of understanding of the interfacial crack formation end propagation phenomena. In this purpose, a specific protocol was used, consisting of interrupted drilling process. Moreover, in order to understand the influence of the bond coat and the ceramic / bond coat interface on cracking, a wide range of samples with specific morphological and mechanical properties were selected. With this in mind, the bond coat was modified by varying spraying parameters, spraying process and also by post treatments on the bond coat. The link between these interfaces and the associated damages due to laser drilling are presented through 2D and 3D observations, destructive and non-destructive, as well as the study of residual stress modification before and after laser drilling for several thermal barrier coatings systems. For further reducing the interfacial crack, several drilling strategies are considered through the laser peak power variation between the different laser pulses needed to drill through the multi-layer material. The results offer interesting perspectives for improving crack resistance of aeronautical engines parts
Rault, François. "Mise en oeuvre et propriétés mécaniques, thermiques et de tenue au feu de filaments à base de polypropylène chargé en nanoparticules". Valenciennes, 2008. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/fdf2aa0d-1453-4fee-8b94-d1e493d57372.
Pełny tekst źródłaThe french textile industry meets stiff competition. The firms try to differentiate themselves by improving or adding new properties to their products. The cost remaining a major concern, PP, polymer with an interesting compromise cost / ownership, is therefore widely used. Different ways exist to functionalize this polymer. One of them is to add fillers. However, the size and rate of particles commonly added to achieve satisfactory properties cause difficulties during the melt spinning process. Due to their characteristics (size and filler rate), nanoparticles offer an interesting alternative to explore. Blends PP / Clay were prepared with a twin-screw extruder before being spun. A strong decrease in the elongation properties of filaments in the presence of clay, probably due to its low exfoliation, brings us to consider the preparation of ternary blends (PP / PA-6 / Clay). However, it was not possible to spin these blends for a filler rate higher than 1 wt% due to their specific morphologies. Filaments of PP filled with clay and graphite and filaments of PP filled with based manganese nanoparticles have also been produced to assess their mechanical and thermal properties. Under air, thermal stability of PP has been improved with all tested fillers. And finally, the filaments made were used to produce knitted fabrics, whose fire properties have been studied with a cone calorimeter
Rogier, Robert. "Matériaux composites à matrice d'aluminophosphate de calcium et à renforcement d'inclusions métalliques biocompatibles : étude des propriétés thermiques, élastiques et mécaniques". Montpellier 2, 1989. http://www.theses.fr/1989MON20202.
Pełny tekst źródłaNigay, Pierre-Marie. "Etude des transformations microstructurales de mélanges argile/biomasse lors de la cuisson et relations avec les propriétés mécaniques et thermiques". Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2015. http://www.theses.fr/2015EMAC0001/document.
Pełny tekst źródłaWaste and biomass valorization appears, on a way of research and advances, as a relevant answer in the challenge offered to the clay bricks industry and housing field. Incorporations of agricultural wastes into clayey ceramic bodies accorded, along those investigations, raw material and energy savings, since improving the mechanical and thermal properties on the basis of every building material. Biomass incorporations amongst argillaceous mixtures induce a porosity formation through the firing process under a release, on a range of temperatures going from 200 to 400°C, of the material spaces previously filled by the organic particles. The porous cavities assume the sizes as well as shapes of the biomass particles and provide a microstructure control affording a functional properties command. The agricultural wastes including thin particles fade out into the clayey bodies and provide, through a median pore size reduction, an improvement of the mechanical strength up to 40%. Crops residues showing fibrous particles induce on the other hand an increase of microstructure and porous network anisotropy, leading to a tremendous improvement of nearly 40% in the insulation behavior. The biomass combustion provides a calorific contribution as well, to the industrial process of firing, surrounding 35% of the usual fuel requirements and supplies an eventual cost of agricultural wastes. Biomass incorporation into clayey ceramic appears as a success on economical, environmental and technical terms, according to the material purpose offering an improvement of the functional performances, and energy purpose assuming a diminution of gas consumptions or a reduction of carbon dioxide release
Begag, Redouane. "Synthèse et propriétés physico-chimiques des carbogels de silice préparés par la méthode sol-gel (en catalyse acide) à partir de polyéthoxydisiloxane". Lyon 1, 1996. http://www.theses.fr/1996LYO10284.
Pełny tekst źródłaTraore, Karfa. "Frittage à basse température d'une argile kaolinique du Burkina Faso : Transformations thermiques et réorganisations structurales". Limoges, 2003. http://aurore.unilim.fr/theses/nxfile/default/390248c6-d1fd-43fc-b69a-a4110e0be600/blobholder:0/2003LIMO0004.pdf.
Pełny tekst źródłaThis work describes the thermal transformation and the sintering process at low temperature (1100°C) of ceramic compositions based on a selected kaolinitic clay from Burkina Faso. It is a very representative clay among those used in this country for the traditional manufacturing of pottery and brick wares or roof tiles. This clay was used as it or mixed with calcite to improve the properties the fired products. The chemical and mineralogical compositions of the clay were analysed as the structural characteristics of the kaolinitic phase, which include all the iron impurity in octahedral sites. The study of thermal transformations of the clay reveals typical thermal transformations very similar to that of a low crystallized kaolinite mineral. Thermal transformations and sintering processes were studied in more details to identify and quantify the mechanism involved, but for the dilatometry characterizations, the intrinsic material behaviour must be separated from the experimental results. We also study the clay-calcite mixes because they proved to increase the mechanical strength of products sintered at low temperature. Since 950°C, these mixes become recrystallized through a reaction- sintering mechanism, which follows a particular crystallization path : metakaolinite-gehlenite-anorthite. These crystallized phases are under the form of small nodules embedded in a silico-aluminate matrix, which is porous and weakly structurally organized. The crystallographic study of the transformation path of phases revealed specific structural transformations with preferential mutual orientations of cristallographic directions and the maintain of calcium atom positions. The mechanical strength of the sintered materials is controlled by the very heterogeneous character of the microstructure. In general, a three dimensional network of anorthite particles are partially interconnected in the matrix phase. The occurence and repartition of connections influence the mechanical properties, together with the porosity of the matrix phase
Villiéras, Frédéric. "Étude des modifications des propriétés du talc et de la chlorite par traitement thermique". Vandoeuvre-les-Nancy, INPL, 1993. http://docnum.univ-lorraine.fr/public/INPL_T_1993_VILLIERAS_F.pdf.
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