[pt] Nesta tese foi estabelecido um procedimento para análise do processo de perfuração e cimentação de poços em camada de sal que engloba tanto o processo de endurecimento do cimento, quanto a resposta de fluência da camada de sal. O objetivo desta tese é analisar o comportamento geomecânico de fluência (creep) na zona de sal antes, durante e depois da perfuração e em seguida na cimentação do poço. Desta forma, a pesquisa tem como meta a avaliação das tensões e deslocamentos ao redor do poço, através da simulação computacional com ajuda do programa comercial numérico de elementos finitos (ABAQUS), além de sub-rotinas do programa FORTRAN. Com esta análise, pretende-se entender os efeitos geomecânicos de interação da pressão exercida pelo fluido de perfuração e do cimento e do comportamento nas tensões na fronteira sal-cimento e cimento-revestimento, dentre outros, para evitar possíveis intervenções em poços que acarretam perdas econômicas. Foram realizadas diversas simulações, destacando-se: (i) estado de tensões in situ antes da perfuração do poço; (ii) tensões induzidas devido à perfuração e à fluência no sal e (iii) cimentação no poço. Nestas simulações considerou-se um poço de petróleo em 2D no estado de deformação plana. O fluido de perfuração foi simulado como não penetrante. Os resultados obtidos das simulações correspondem aos deslocamentos radiais e tensões radiais e tangenciais. / [en] In this dissertation, an analysis procedure was established for the drilling and casing cementing process in salt wellbores, which encompasses cement hardening as well as salt creep. The objective of this dissertation is to analyze the geomechanical behavior of salt creep before, during and after drilling as well as the wellbore casing cementing process. Thus, the purpose of this study is to evaluate stresses and displacements around the wellbore through computational simulation with the finite element commercial software program Abaqus together with FORTRAN sub-routines. This analysis intends to understand the geomechanical effects of the interaction of the drilling fluid and slurry pressures against the wellbore and the behavior of the stress interactions between the two existing boundaries casing-cement and cement-salt formation; thus avoiding unnecessary workover operations that provoke economical losses. Diverse process simulations were performed including: (i) in situ stresses prior to drilling (ii) induced stresses due to drilling and salt creep and (iii) wellbore cementing. In these simulations, a 2D plane strain wellbore was considered. The drilling fluid was assumed to be non-penetrable with respect to the wellbore formation. Finally, the results were expressed in terms of radial displacement along with radial and tangential stresses.

[pt] O interesse deste trabalho está baseado no estudo da influência das diferentes condições e meios de envelhecimento nas propriedades mecânicas, térmicas, estruturais e químicas do polietileno de alta densidade (PEAD) utilizado para a fabricação das tubulações para o transporte de óleo e gás. Foram fabricados corpos de prova com o formato para o teste de tração tipo V segundo a norma ASTM D638. Para o desenvolvimento deste trabalho os corpos de prova foram submetidos a diferentes tipos de envelhecimento em diferentes meios, a saber: i) radiação UV com uma energia radiante de comprimento de onda de 365 nm e tempos de exposição de 8, 12 e 18 semanas; ii) envelhecimento sob temperatura, os corpos de prova foram imersos em três diferentes tipos de óleo lubrificantes, a 50, 70 e 90 graus celsius em tempos de 2, 3, 4 e 6 meses; iii) envelhecimento sob pressão, onde os corpos de prova foram submetidos a 7, 14 e 17 bar e imersos em água corrente a 50 graus celsius durante 1 e 2 semanas e no óleo padrão BASIC OB 440 a 70 graus celsius durante 1, 2 e 5 semanas. As amostras envelhecidas foram caracterizadas por difração de raios X, espectroscopia infravermelha, espectroscopia RAMAN, calorimetria diferencial de varredura, análise termogravimétrica, ensaio de tração, ensaios de fluência, índice de fluidez, microscopia eletrônica de varredura e microscopia óptica. Os resultados das caracterizações das amostras após envelhecimento foram comparados com os resultados obtidos do PEAD virgem, cujas propriedades foram obtidas usando os mesmos métodos de caracterização. Foi avaliado, ainda, o comportamento viscoelástico do PEAD, mediante a simulação matemática dos modelos viscoelásticos, partindo dos resultados experimentais dos testes de fluência antes e após de envelhecimento. Os resultados obtidos demostraram que comportamento mecânico do PEAD após ser envelhecido foi fortemente influenciado pelas diferentes variáveis, como temperatura, pressão, meio e tempo de exposição. Sendo que a soma de cada efeito gerado por cada parâmetro contribui para a variação do desempenho mecânico do polímero. Qualquer que seja a variável externa imposta ao PEAD, temperatura, tempo, pressão ou meio de exposição, sempre acarretam alterações nas propriedades mecânicas. Porém, dependendo de qual dos parâmetros mencionados anteriormente seja o predominante, o envelhecimento do PEAD será mais ou menos relevante. Da simulação do comportamento sob fluência, o modelo dos 4 parâmetros foi quem apresentou a melhor descrição gráfica e aproximação matemática do comportamento experimental. / [en] The interest of this work was based on the study of the influence of different aging conditions and medium in mechanical, thermal, structural and chemical properties of high-density polyethylene (HDPE) used for the manufacture of line pipes for transporting oil and gas. Prototypes for type-V tensile testing according to ASTM D 638. For development this work, the samples were submitted to different types of aging in different medium, namely: i) UV irradiation with a radiant energy with 365 nm of wavelengths and exposure times of 8, 12 and 18 weeks; ii) For aging under temperature, the samples were immersed in three different types of lubricating oil, to 50, 70 and 90 celsius degree for periods of 2, 3, 4 and 6 months; iii) aging under pressure, where the samples were submitted to 7, 14 and 17 bar and immersed in ordinary water at 50 celsius degree for 1 and 2 weeks and pattern Oil BASIC B 440-70 celsius degree for 1, 2 and 5 weeks. The aged samples was characterized by X-ray diffraction, infrared spectroscopy, Raman spectroscopy, differential scanning calorimetric, thermal gravimetric analysis, tensile and creep tests, melt flow rate, scanning electron microscopy and optical microscopy. The results of the characterization of the samples after aging were compared with the results obtained from virgin HDPE, whose properties were obtained using the same characterization methods. Besides, was evaluated, the viscoelastic behavior of the HDPE, by mathematical simulation of viscoelastic models, based on experimental results of creep tests before and after aging. The results showed that mechanical behavior of HDPE after aging was strongly influenced by different variables, such as temperature, pressure, medium and exposure time. Since the sum of each effect generated by each parameter contributes to the variation of the mechanical performance of the polymer. Whichever the external variable imposed on HDPE - temperature, time, pressure, or exposure medium - always leads to changes in mechanical properties. However, depending on which of the parameters mentioned above is predominant, the aging HDPE will be more or less relevant. Simulating the creep behavior, the four parameters model was the one who presented the best graphic and mathematical description approximation of the experimental behavior.

The present work has been produced as part of an on-going collaboration between the University of Manchester and Amec, with the primary aim of furthering mechanistic understanding of corrosion processes in zirconium alloys out-of-reactor. Zirconium alloys are used as cladding material for nuclear fuel pellets, and correct understanding of the corrosion process in autoclave is essential to predicting material behaviour in-reactor. This EngD thesis is composed of five proposed papers that investigate observations and hypotheses under the theme of mechanical degradation in oxides formed on zirconium alloys in autoclave. First investigations concern observed stress relaxation in zirconium oxide. Finite element analysis is used to capture mechanical aspects of the corrosion process and apply this to stress behaviour determined previously using synchrotron x-ray diffraction. The results indicate that a mechanism other than creep or hydrogen induced lattice strain must be present to account for the observed stress relaxation. One such potential mechanism is crack formation; statistical analysis of scanning electron microscopy images has been used to identify a link between the development of roughness at the metal-oxide interface, crack formation in the oxide and transition points or acceleration in the corrosion kinetics. Parameters such as the median radius of curvature and profile slope (Rdq) have been applied, as these parameters do not require the definition of a periodic wavelength or amplitude. These and other parameters are related to information in literature to indicate that for samples of Zircaloy-4 and ZIRLOTM, which go through transition, the interface roughness changes in a way that would increase localised stress concentrations. The third material is an experimental low tin alloy, which under the same oxidation conditions, and during the same time period, does not appear to go through transition and does not develop an interface roughness in the same way. A critical assessment of finite element analysis applied to oxidising non-planar interfaces shows the significant limitations in the existing mechanism for representing oxidation expansion and stress formation. Autoclave oxidation experiments of artificially roughened samples of Zircaloy-4 were carried out to further understand the impact of out-of-plane stress generation. The results indicate a divergence based on surface roughness after ~86 days oxidation. SEM examination of images in cross section highlighted accelerated oxidation above surface roughness peaks, and an increased crack area in rougher samples. Finally, finite element analysis of the tetragonal to monoclinic phase transformation showed that biaxial compressive stress relaxation, or the tri-axial tensile stress associated with an advancing crack tip, could reduce the transformation strain energy and destabilise the tetragonal phase. The volumetric expansion and shear strain associated with the phase transformation produces stress in the surrounding oxide sufficient to generate nano-scale cracks perpendicular to the metal-oxide interface. This would allow fast ingress routes for oxygen containing species, and therefore acceleration in the corrosion kinetics.

Lors de la construction de structure réalisée en plusieurs phases de bétonnage, les déformations du béton sont restreintes durant son durcissement. Quand le retrait est restreint, des contraintes de traction sont induites dans le matériau et un risque de fissuration est présent. Il est alors nécessaire de modéliser l’évolution des propriétés au jeune âge afin de prédire le comportement de la structure durant le jeune âge du béton. La difficulté réside dans le fait que la modélisation des propriétés du béton doit être basée sur des données expérimentales au jeune âge et que ces données doivent être obtenues automatiquement car le durcissement du béton se produit rapidement pendant les premières heures et les premiers jours. La thèse porte sur l’étude expérimentale et numérique des propriétés au jeune âge des matériaux à base de ciment et plus particulièrement sur le développement des déformations endogènes, le coefficient de dilatation thermique, le module d’élasticité et le fluage propre en compression et en traction. A cet effet, un travail complet a été réalisé à l'ULB et à l’Ifsttar impliquant le développement d'une nouvelle approche avec de nouvelles procédures d'essai et la conception de nouveaux dispositifs d'essai pour générer des données expérimentales depuis la prise du matériau. La méthodologie est basée sur deux méthodes d'essai répété. Pour la caractérisation du comportement viscoélastique d'un béton depuis sa prise, un essai de chargement permanent couplé à un essai avec des chargements répétés de plusieurs minutes est nécessaire. Les déformations endogènes, le coefficient de dilatation thermique et la prise sont caractérisés avec des variations thermiques répétées sur un échantillon de béton. Cette nouvelle approche a été définie sur un béton ordinaire et ensuite étendue sur l’étude de 4 paramètres pertinents : le rapport eau-ciment, l'effet de restriction de l'agrégat sur la pâte de ciment dans le développement des propriétés du béton au jeune âge, la substitution du ciment par des additions minérales et la différence de comportement en traction et en compression. Sur la base de ces résultats expérimentaux, de nouveaux modèles ont été développés pour la caractérisation des propriétés au jeune âge de matériaux cimentaires depuis le temps de prise. Une version adaptée de la modélisation du fluage propre dans le Code modèle 2010 est également proposée / For usual concrete structure built in several phases, concrete deformations are restrained during the hardening process. When shrinkage is restrained, tensile stresses are induced and a cracking risk occurs. Modelling the evolution of an early age set of parameters on concrete is necessary to predict the early age behaviour of concrete structures. The difficulty lies in the fact that the modelling of concrete properties must be based on experimental data at early age and this data must be obtained automatically because the hardening process of the concrete takes place rapidly during the first hours and also the first days. The thesis deals with experimental and numerical study of the early age properties of cement based materials and more specifically the development of the autogenous deformation, the coefficient of thermal expansion, the E-modulus and the basic creep in compression and tension. For this purpose, a comprehensive work was carried out at ULB and Ifsttar involving the development of a new approach with new test procedures and the design of new testing devices to generate experimental data since the setting of the material. The methodology is based on two repeated testing methods. For the characterization of the viscoelastic behaviour of a concrete since setting, a permanent loading coupled to a test with repeated minute-long loadings is needed. Whereas, the autogenous strain, the coefficient of thermal expansion and the setting are characterized with repeated thermal variations on a concrete sample. The new approach was defined on an ordinary concrete and then extended to the study of the following parameters: the water-cement ratio, the restrained effect of aggregate on the cement paste in the development of concrete properties at early age, the substitution of cement by mineral addition and the difference of behaviour in tension and in compression. Based on these experimental results, new models were developed for the characterization of the early age properties of cement based materials since setting time. An adapted version of the Model Code 2010 for the modelling of basic creep is also proposed

Les aciers inoxydables austénitiques sont utilisés dans de nombreuses applications. L'alliage 310S possède des teneurs en chrome et en nickel particulièrement élevées qui lui confèrent une excellente résistance pour les utilisations à hautes températures. Néanmoins, pour des applications combinant cyclage thermique et chargement mécanique, la prédiction de la durée de vie des pièces est délicate. En effet, si de nombreuses données sont disponibles dans la littérature concernant le vieillissement et le fluage isotherme des aciers austénitiques, celles dédiées aux sollicitations couplées sont très rares et s’avèrent insuffisantes pour rendre compte des phénomènes macroscopiques observés industriellement. Une étude a donc été menée pour comprendre les mécanismes mis en jeu. Le vieillissement d’un acier 310S a été exploré pour plusieurs cycles thermiques à 870°C. Les microstructures obtenues ont été caractérisées par différents moyens expérimentaux. L’effet critique du cyclage thermique sur la germination et la croissance des précipités a été quantifié mettant en évidence une accélération de la germination de la phase sigma. D’autre part, des essais mécaniques à 20, 650, 780 et 870°C ont été réalisés sur une large plage de contraintes. Les résultats confirment la forte influence de la modification de la microstructure sur les propriétés élastiques et sur celles en fluage. L’augmentation conjointe du module d’Young, de la limite à rupture et des vitesses de fluage a été observée. La prédiction de la durée de vie de composants subissant des cyclages thermomécaniques doit donc tenir compte de l’évolution de la microstructure. Ces travaux aboutissent donc à une double modélisation qui permet, d’une part, de décrire la cinétique de transformation de phase et, d’autre part, de prédire les vitesses de fluage de l’acier 310S, en isotherme comme en cyclage thermomécanique, dans des conditions représentatives des conditions de service des pièces industrielles. / Austenitic stainless steels are widely used in industrial applications. 310S stainless steel has high chromium and nickel contents, providing a competitive mechanical behavior for high temperature utilizations. Nevertheless, lifetime prediction is difficult to assess under coupled mechanical and thermal solicitations. Many data are available on aging and isothermal creep of austenitic stainless steels, but few consider the coupled effect of multiple solicitations. These data are insufficient to explain industrial macroscopic observations. The aim of this study was thus to explore the involved mechanisms in such a case. 310S stainless steel aging was investigated under various thermal cycling solicitations at 870°C. The obtained microstructures were characterized by numerous experimental means. The effect of thermal cycling on nucleation and growth of sigma phase precipitates was quantified. The results of the present work revealed enhanced sigma phase nucleation in these non-isothermal conditions. In addition, mechanical tests were carried out at 20, 650, 780 and 870°C under a large range of stresses. The results highlight a noticeable influence of microstructural evolution on elastic and creep properties of this alloy. Simultaneous increases of Young modulus, rupture stress and creep rates were evidenced. It was thus evidenced that lifetime prediction of components under thermomechanical cycling must take into account the microstructure change during lifetime. Finally, two models were proposed in order to assess microstructural changes and creep behavior that apply to isothermal and thermomechanical cycling conditions mimicking in service conditions of industrial components.

Corrosion of steel tendons is a major problem for post-tensioned concrete, especially because corrosion of the steel strands is often hard to detect inside grouted ducts. Non-metallic tendons can serve as an alternative material to steel for post-tensioning applications. Carbon fiber reinforced polymer (CFRP), given its higher strength and elastic modulus, as well as excellent durability and fatigue strength, is the most practical option for post-tensioning applications. The primary objective of this research project was to assess the feasibility of the use of innovative carbon fiber reinforced polymer (CFRP) tendons and to develop guidelines for CFRP in post-tensioned bridge applications, including segmental bridges and pier caps. An experimental investigation and a numerical simulation were conducted to compare the performance of a scaled segmental bridge model, post-tensioned with two types of carbon fiber strands and steel strands. The model was tested at different prestress levels and at different loading configurations. While the study confirms feasibility of both types of carbon fiber strands for segmental bridge applications, and their similar serviceability behavior, strands with higher elastic modulus could improve structural performance and minimize displacements beyond service loads. As the second component of the project, a side-by-side comparison of two types of carbon fiber strands against steel strands was conducted in a scaled pier cap model. Two different strand arrangements were used for post-tensioning, with eight and six strands, respectively representing an over-design and a slight under-design relative to the factored demand. The model was tested under service and factored loads. The investigation confirmed the feasibility of using carbon fiber strands in unbonded post-tensioning of pier caps. Considering both serviceability and overload conditions, the general performance of the pier cap model was deemed acceptable using either type of carbon fiber strands and quite comparable to that of steel strands. In another component of this research, creep stress tests were conducted with carbon fiber composite cable (CFCC). The anchorages for all the specimens were prepared using a commercially available expansive grout. Specimens withstood 95% of the guaranteed capacity provided by the manufacturer for a period of five months, without any sign of rupture.

The nanostructure, physical properties and mechanical performance of C-S-H, 1.4 nm tobermorite, jennite, and ettringite were studied. C-S-H of variable stoichiometries was examined as a model system in comparison with that produced in the hydration of Portland cement. The current Master’s thesis is comprised of four research papers designed to improve the current understanding of the nanostructure and engineering properties of C-S-H systems and modified C-S-H systems. Many of the controversial issues in cement science were identified and were addressed in a comprehensive research study, which examined the key features of the C-S-H systems at the nano-structure level. In Chapter 4, each paper presented new evidence for a number of mechanical aspects of C-S-H materials. Numerous advanced analytical tools were used in order to verify the observations made in each section. The major achievements of the current work are mentioned briefly as follows: 1. It was determined that microindentation is a useful method for determining the creep behavior of C-S-H of various stoichiometries, 1.4 tobermorite, jennite, and ettringite. 2. Microindentation parameters i.e. creep modulus, indentation modulus and indentation hardness are porosity dependent. 3. Microindentation creep measurements on C-S-H (C/S = 0.80 and 1.20) demonstrated that creep modulus, indentation modulus, and indentation hardness are all dependent on mass-loss from the 11%RH condition. 4. Evidence was presented that the nanostructural role of interlayer water in C-S-H has a significant influence on the creep process.

Turbine components operate under severe loading conditions and at high and varying temperatures that result in thermal stresses in the presence of temperature gradients created by hot gases and cooling air. Moreover, static and cyclic loads as well as the motion of rotating components create mechanical stresses. The combined effect of complex thermo-mechanical stresses promote nucleation and propagation of cracks that give rise to fatigue and creep failure of the turbine components. Therefore, the relationship between thermo-mechanical stresses, chemical composition, heat treatment, resulting microstructure, operating temperature, material damage, and potential failure modes, i.e. fatigue and/or creep, needs to be well understood and studied. Artificial neural networks are promising candidate tools for such studies. They are fast, flexible, efficient, and accurate tools to model highly non-linear multi-dimensional relationships and reduce the need for experimental work and time-consuming regression analysis. Therefore, separate neural network models for γ’ precipitate strengthened Ni based superalloys have been developed for predicting the γ’ precipitate size, thermal expansion coefficient, fatigue life, and hysteresis energy. The accumulated fatigue damage is then estimated as the product of hysteresis energy and fatigue life. The models for γ’ precipitate size, thermal expansion coefficient, and hysteresis energy converge very well and match experimental data accurately. The fatigue life proved to be the most challenging aspect to predict, and fracture mechanics proved to potentially be a necessary supplement to neural networks. The model for fatigue life converges well, but relatively large errors are observed partly due to the generally large statistical variations inherent to fatigue life. The deformation mechanism map for 1.23Cr-1.2Mo-0.26V rotor steel has been constructed using dislocation glide, grain boundary sliding, and power law creep rate equations. The constructed map is verified with experimental data points and neural network results. Although the existing set of experimental data points for neural network modeling is limited, there is an excellent match with boundaries constructed using rate equations which validates the deformation mechanism map.

L'utilisation croissante de composites biosourcés dans des applications de plus en plus techniques pose le problème de la prédiction de leur vieillissement dans des conditions réelles d'utilisation. En effet l'environnement dans lequel ils évoluent, conjugue généralement des sollicitations de nature thermique, hydrique et mécanique. Le comportement complexe de chaque constituant (fibre et matrice, et même leur interface) et donc du matériau composite dans sa globalité vis-à-vis de ces dégradations restent mal connu.L'objectif de ce travail est d'apporter des éléments de réponse à cette problématique en étudiant, de manière extit{ex situ} et extit{in situ}, le comportement de biocomposites poly(acide lactique) renforcés de fibre de lin soumis à un vieillissement couplé thermo-hydro-mécanique. Pour différents taux de renfort, l'influence de la présence d'eau à différentes températures couplée ou non à des contraintes de fluage a été évaluée.Dans un premier temps, la caractérisation de ces biocomposites dans un environnement thermo-hydrique a permis d'identifier les phénomènes mis en jeu. Plusieurs propriétés physiques, chimiques, thermiques et mécaniques ont été déterminées au cours de la diffusion. Par la suite, les conséquences irréversibles des phénomènes de vieillissement sur ces propriétés ont été évaluées. Dans un troisième temps, l'introduction de sollicitations mécaniques comme facteur supplémentaire de vieillissement a permis d'apprécier les effets du couplage thermo-hydro-mécanique. Enfin un modèle de calcul par éléments finis a été mis au point afin de pouvoir simuler le comportement physique et mécanique des biocomposites dans un environnement thermo-hydrique donné. / The growing demand for bio-based composites intended for high standard applications bring to light the specific problems of aging prediction in real life conditions. The various environment in which these products are likely to be used lead to different kinds of damage (hydric, thermal and mechanical). The complex behavior of each component (fiber, matrix, and even their interface), and thus the behavior of the composite material, are generally poorly understood.The objective of this work is to provide possible answers to these inter-related problems by studying, extit{ex situ} and extit{in situ}, the behavior of PLA/flax biocomposites subjected to a coupled thermo-hydro-mechanical aging. The influence of the presence or the absence of water at different temperatures coupled to a creep stress was assessed for different fiber contents.At first, the characterization of these biocomposites in a thermo-hydric environment allowed to identify the involved phenomena. Several physical, chemical and mechanical properties were determined during diffusion. Then, the irreversible consequences of thermo-hydric aging on these properties were assessed. Thirdly, the subjection of materials to additional mechanical loadings made possible the evaluation of the effects of thermo-hydro-mechanical couplings. Finally, a finite element model was established in order to simulate the physical and mechanical behavior of biocomposites in a given thermo-hydric environment.

L'objet de cette thèse est l’étude du comportement des fissures dans le verre. En particulier, l’évaluationde l’effet à long terme des contraintes en compression, est étudié par des essais de fluage. Le dispositifexpérimental utilisé est une presse triaxiale qui permet de confiner des échantillons cylindriques et de leurappliquer des contraintes axiales, une pression de pore ainsi qu’une variation de température. Un réseaude capteurs fixés sur chaque échantillon permet de mesurer la déformation, les vitesses de propagation desondes élastiques et les émissions acoustiques. Les échantillons de verre fournis pour cette étude sont fabriquéspar le CEA de Marcoule. Nous avons observé que le verre sain présente un comportement élastiquefragileet une grande résistance mécanique. Un réseau de fissures est ensuite introduit par choc thermique.L’étude de la microstructure du réseau initial a révélé que le choc thermique induit des contraintes detension aux bords de l’échantillon qui nucléent les fissures. Le réseau introduit est homogène et présenteune symétrie transverse isotrope. La densité de fissure du réseau peut être mesurée à partir d’images demicroscopie et aussi à partir des mesures de vitesses. L’étude de fluage a mis en évidence la propagationsouscritique des fissures. Un modèle théorique, reliant une loi de propagation des fissures à une descriptionen “wing-crack”, décrit bien le comportement expérimental. Une dernière étude est abordée qui met enévidence le rôle des fluides dans la propagation des fissures. À l’échelle du temps du laboratoire on montrealors que l’eau peut accentuer la propagation des fissures et qu’une corrosion chimique est aussi mesurable. / The purpose of this thesis is the study of crack behavior in glass. In particular, the long term effects ofcompressive stresses are observed through creep tests. The used experimental apparatus is a triaxial celldesigned to investigate the mechanical and physical properties of rocks under conditions of effective pressure,deviatoric stress, pore pressure and temperature. A set of sensors allows to measure radial and axialstrain, elastic wave velocities and acoustic emissions. The original boro-silicate glass samples are producedby the French Atomic Energy Commission (CEA). We observe that original glass has an elastic-brittlebehavior and a high mechanical strength. Then, the studied crack network is introduced with a thermalshock. The microstructural study of the initial crack network reveals that the thermal shock induces tensilestresses at sample edges which nucleate cracks. The network is homogeneous and has a transverseisotropic symmetry. The crack density can be measured from Scanning Electron Microscopy images andcan also be inferred from elastic wave velocities. Creep experiments evidenced the sub-critical crack propagation.A theoretical model, that links a crack propagation law to a “wing-crack” geometry, describesthe experimental behavior. A last point is reported that investigates the fluid role in crack behavior. Weobserve that the crack propagation is enhanced by the presence of a pore fluid. Chemical corrosion canalso be measured at our laboratory scale.