Afin de conditionner les déchets technologiques issus du démantèlement de l’Atelier de Vitrification de Marcoule au Commissariat à l’Energie Atomique et aux énergies alternatives (CEA), leur blocage dans une matrice cimentaire est envisagé. Dans ce contexte, l’effet des rayonnements ionisants issus des déchets nucléaires sur la matrice de confinement doit être examiné afin de garantir d’une part l’intégrité du colis, et d’autre part une production de gaz de radiolyse limitée. Ce travail de thèse s’intéresse au comportement sous irradiation gamma et électronique de trois types de matériaux cimentaires aux constituants différents et se focalise sur la production de gaz de radiolyse et sur l’évaluation de la résistance physique à travers l’observation des modifications structurales. Le sujet est traité par une double approche à la fois sur pâte de ciment et sur phases modèles, c’est-à-dire sur les hydrates constitutifs des pâtes de ciment synthétisés indépendamment. Il apparaît clairement que l’eau porale ainsi que les hydrates constitutifs contribuent à la production d’hydrogène radiolytique, avec une forte variation selon la nature des matériaux cimentaires. Ainsi, les ciments à base d’aluminates de calcium et les ciments phospho-magnésiens présentent un intérêt notable par rapport aux ciments silico-calciques usuels quant à la production d’hydrogène. Aux très fortes doses (plusieurs GGy) la résistance structurale sous irradiation électronique a été évaluée par diffraction de rayons X. Les hydrates constitutifs des trois familles de ciment étudiées présentent une bonne résistance structurale. Malgré la présence de variations dimensionnelles et microstructurales, ils ne s’amorphisent pas sous irradiation, ce qui s’avère positif en vue de l’application industrielle envisagée. / In order to treat the technological waste arising from the dismantling of the Marcoule Vitrification facility of the French Atomic Energy Commission (CEA), conditioning in a cement matrix is being put forward. Within this context, the impact of ionizing radiation produced by the nuclear waste on the confinement matrix ought to be investigated in order to ensure both the integrity of the package and the limitation of the radiolytic gas production. This thesis investigates the behavior of three types of cement compounds with distinct constituents under gamma and electronic radiation. This study deals with both the radiolytic gas production and the physical resistance of the materials using a structural modification examination. A double and complementary approach is used treating cement pastes and synthetic cement compounds together. It clearly appears that the pore water and the hydrates themselves both contribute to the radiolytic hydrogen production, with a significant variation depending on the nature of the materials. As far as radiolysis is concerned, calcium aluminate-based cements and magnesium phosphate cements are of considerable interest in comparison with the usual calcium silicate cements. At very high doses (GGy range), the structural resistance under electron irradiation was evaluated by X-ray diffraction. The constituent hydrates of the three cement types studied exhibit a good structural resistance. Despite the presence of dimensional variations at the unit cell scale as well as microstructural evolution, no amorphization is observed under irradiation, which is an interesting result with respect to the intended industrial application.

FBC-ashes, as a waste product of a relatively new technology of combustion, so-called fluidized bed combustion, cannot be used for building materials production in contrast to fly-ashes. Problem rests in their chemical as well as their mineralogical composition. Thought it can be admitted that FBC-ash may be used for preparation of the hydraulic binder with a similar chemical and mineralogical composition, but only in a certain limit of concentration. The first part of this thesis was focused on the potentialities of fluid fly ashes utilization as hydraulic bonding material in preparation of dry mortar mixtures and the second part of works was engaged in research development of burned hydraulic binder of FBC ash. The thesis explores the conjunction between parameters of burning mode and hydraulic binder characteristics.

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Betong är ett material som används dagligen och finns i allt från skyskrapor och tunnlar till skulpturer och möbler. Tryckhållfastheten är en av betongens viktigaste egenskaper och med en konstant utvecklande bransch där det byggs mer och mer är det avgörande att betongen som används håller. Normhållfastheten hos cement kontrolleras regelbundet och visar i vissa fall variationer utanför cementens normala spann. Cementillverkare upptäcker dessa avsteg genom att granska varje leverans som produceras samt genom egna produktkontroller på fabriken. Vid upptäckta felmarginaler finns krav på att berörda kunder i branschen måste informeras för att exempelvis få en möjlighet till att kunna korrigera recept inför betongblandningen. Vid en lägre normhållfasthet i cement skapas generellt en lägre hållfasthet i betong och för att justera avvikelsen ökar betongtillverkare mängden cement i recepten för att kunna leverera en produkt med utlovad hållfasthet till kund. Slutresultatet kommer att hjälpa betongtillverkare att förutse hur betongen kan påverkas av en variation i cementens hållfasthet och vara ett hjälpmedel för hur receptet ska hanteras för att täcka upp eventuella variationer så att kunderna inte påverkas i lika stor grad. Arbetet innefattar tre betongrecept med separata vct som testas med cementen Anläggningscement Slite i en grov-, mellan- och finmald version. Gjutningen sker i Cementa Research laboratorium i Liljeholmen och sammanlagt utförs 18 gjutningar med 22 liter betong per gjutning. Totalt gjuts 216 kuber som sedan trycktestas vid 7 respektive 28 dygn i samma lokal. Data har sedan sammanställts för att kunna jämföras mot cementens normhållfasthet som har testats i Cementas lab i Slite. Arbetet har utförts åt Cementa AB och Thomas Concrete Group AB för att kontrollera sambandet mellan normhållfastheten i cement och den färdiga betongens hållfasthet. Sambandet är av stor vikt i den dagliga produktionen och är något som efterfrågats under lång tid. Resultatet från gjutningarna visar att det finns ett samband till en viss grad men på grund av komplikationer under gjutningarna har vissa värden inte blivit som förväntat. / Concrete is one of the world's most important building materials and is used in everything from skyscrapers, tunnels to sculptures and furniture. The strength of concrete is important and with a constantly developing industry where more and more is being built, it is vital that the concrete that is used holds. The work is performed on behalf of Cementa AB and Thomas Concrete Group AB to investigate the relation between the strength of cement and the strength of the concrete. The relation is of great importance in daily production and is something that has been requested for a long time. The standard strength of cement is checked regularly and shows in some cases deviations outside the normal range of the cement. Cementa detects these deviations by controlling shipped cement and by the product controls at the factory. If margins of error are discovered, there are requirements for those involved in the industry that they must inform the customers in order for them to correct their concrete mixes accordingly. At a lower standard strength in cement, a lower strength in concrete is generally created and to correct the deviation, the affected amount of cement in the recipe increases in order to be able to deliver a promised product to the customer. The end result will help concrete manufacturers predict how the concrete can be affected by a deviation of the strength of the cement and be a tool for how the recipe should be handled to cover any deviations so that customers are not affected to the same extent. The work includes three concrete recipes with separate w/c-ratios that were tested with the cement CEM I 42,5 N SR3 MH/LA in a coarse, medium and finely milled version. The casting took place in Cementa Research's laboratory in Liljeholmen and in summary, 18 castings were performed with 22 liters of concrete per casting. A total of 216 cubes were cast and then pressure tested at 7 and 28 days. The data has then been compiled to be able to be compared with the cement's standard strength that has been tested in Cementa's lab in Slite.

No / The presence of free water in mortars destined for silo or bagged storage can lead to the degradation of the binder phase. Such water may be present as a result of using wet, as-delivered sand or as a consequence of prior processes such as de-activation of Roman cement. Thus, water must be removed from the system prior to storage. Part 1 of this paper describes the control of a technique by which quicklime is added to the wet system which principally dries it by both slaking the quicklime and evaporation as a consequence of the exothermic slaking reaction. Two examples of mortars are presented in which excess water is removed from the system by the inclusion of quicklime. In the first, the water is present in the as-delivered sand and the binder is a combination of the slaked lime and ggbs. In the second, the water remains after pre-hydration of a Roman cement which is a process to retard its rapid setting characteristics. It is shown that optimally dried mortars are not subject to degradation following storage of both mortar types. (C) 2015 Elsevier Ltd. All rights reserved.

Les mélanges de ciment sulfoalumineux et de ciment Portland sont des liants hydrauliques innovants permettant de moduler les propriétés des bétons, telles que la vitesse de montée en résistance ou la stabilité dimensionnelle. Les performances du liant peuvent ainsi être ajustées pour de nombreuses applications. Au-delà de cet avantage, les émissions de dioxyde de carbone liées à la production du ciment sulfoalumineux sont significativement réduites comparées à celles du ciment Portland traditionnellement utilisé. La diversité des propriétés de ces liants résulte de la variété des mélanges pouvant être réalisés à partir des deux constituants de base. Chaque mélange présente alors une cinétique d'hydratation et des propriétés qui lui sont propres. Par exemple, certains liants sont expansifs mais présentent une montée en résistance progressive, tandis que d'autres sont stables dimensionnellement alors que leur résistance stagne après quelques jours d'hydratation. L'identification et le contrôle des paramètres à l'origine de ces comportements sont donc nécessaires pour garantir des propriétés spécifiques à un usage donné : chape, mortier de réparation, élément préfabriqué, etc. C'est l'objectif de cette étude qui s'attache à déterminer la cinétique, la minéralogie et les propriétés associées à l'hydratation de trois mélanges contenant 85 %, 70 % et 40 % de ciment Portland. Les essais entrepris ont aussi permis d'aboutir à une modélisation thermodynamique des mécanismes d'hydratation. L'impact de la composition du ciment Portland est également étudié. Enfin, il est montré que l'anhydrite et la chaux sont deux leviers qui modifient radicalement le processus d'hydratation et permettent ainsi d'adapter les propriétés d'un mélange aux exigences de son utilisation / Blends of ordinary Portland cement and sulfoaluminate cement are innovative hydraulic binders allowing control of concrete properties such as hardening speed or dimensional stability for specific applications. Moreover, carbon dioxide emissions linked to sulfoaluminate cement are significantly reduced compared to ordinary Portland cement. The binder properties can be adjusted due to the diversity of blends conceivable with these two constituents. Each blend has its own hydration kinetic and properties. For example, some blends are expansive and the hardening is progressive whereas other mixtures are dimensionally stable but their strength stagnates after few days. Identification and control of the parameters responsible of these comportments are necessary in order to guaranty specific properties for each application: screed, repairing mortar, etc. This is the aim of this study which described the hydration kinetic, the properties and composition of three blends containing 85 %, 70 % and 40 % of Portland cement. These experiments are completed by thermodynamic modeling of the hydration mechanisms. The effect of the Portland cement composition has also been tested. Finally, it's shown that anhydrite and calcium hydroxide are two key parameters which modify radically the hydration process and allow the properties adjustment required for the blend used

O cimento ósseo, utilizado para a fixação de componentes protéticos nas cirurgias de substituição articular, mais resistente às forças de compressão do que às forças de tração, tem suas propriedades mecânicas alteradas por vários fatores entre esses a formulação comercial e o método de preparação empregado. É o objetivo deste trabalho avaliar comparativamente as propriedades mecânicas à compressão de duas formulações comerciais de cimento ósseo preparadas manualmente e a vácuo, segundo as instruções do fabricante. Um conjunto de moldagem confeccionado em aço inoxidável permitiu preparar 48 corpos de prova para cada grupo experimental, totalizando 192 corpos de prova, que foram testados na Máquina Universal de Ensaios, tendo as especificações baseadas nas normas ISO 5833 e ASTM F451-86. A elaboração do diagrama tensão x deformação de cada grupo experimental analisou as propriedades mecânicas do cimento ósseo quanto ao módulo de elasticidade, tensão e deformação no limite de proporcionalidade, entre grupos de mesma formulação comercial e entre os grupos com mesmo método de mistura. Analisados estatisticamente pelo método de Variança de Kruskal-Wallis (p ≤0,001) e pelo método de Dunn's (p ≤0,05). Quanto ao módulo de elasticidade, o grupo 2M foi o que apresentou maior módulo, 1563 MPa, valor estatisticamente significante (p ≤ 0,05) em relação aos grupos 1M, 1V e 2V. Para a tensão no limite de proporcionalidade os grupos 1M (39,40 MPa) e 2V (39,65 MPa) foram os maiores valores de tensão no limite de proporcionalidade, não havendo diferença estatisticamente significante entre eles, mas essas diferenças foram significativas quando comparadas aos grupos 1V e 2M. A deformação no limite de proporcionalidade de maior valor percentual foi para o grupo 1M, 3,36%, sendo esta diferença estatisticamente significante quando comparado ao grupo 2M. Os testes de resistência à compressão do cimento nacionalizado e importado, preparados manualmente e a vácuo, mostraram não haver diferença importante entre os dois tipos de cimento ósseo, nem entre as duas formas de misturá-los. / The bone cement used for the fixation of the prosthetic components in the surgeries of joint replacement, more resistant to the compression than to the traction, has its mechanical properties altered by several factors among those the commercial formulation and preparation employee's method. It is the objective of this work to evaluate the mechanical properties to the compression of the two commercial formulas of bone cement manually prepared and using vacuum, according to the manufacturer's instructions. A molding set was made in stainless steel and it allowed for the preparation of 48 bodies of proof for each experimental group, adding up to 192 proof bodies total which were tested in the Universal Rehearsal Machine, with the specifications based on the ISO 5833 and the ASTM F451-86 regulations. The elaboration of the diagram "tension vs. deformation" of each of the experimental group analyzed the mechanical properties of the bone cement in relation to the elasticity module, tension and deformation on the proportional limit among the groups with the same commercial formula and among the groups with the same mixture method. Analyzed statistically, by Kruskal-Wallis's method of the variation (p ≤0.001) and by the Dunn’s method (p ≤0.05). Regarding the elasticity, the group 2M was the one with the highest module, 1563 MPa, a statistically significant value (p ≤0.05) in relation to the groups 1M, 1V and 2V to the tension at the limit of the proportionality, there is no significant differences among them, but these differences were relevant when compared to groups 1V and 2M. The deformation at the limit of the proportionality of the highest percentage was to group 1M, 3.36%, being this the relevant statistical difference when compared to group 2M. The resistance tests to the compression of the national and international cement prepared manually and by vacuum show that there is no important difference between the two kind of bone cement, and neither between the two ways of mixing them.

The specific objectives of this research were to quantify the effects of certain environmental factors on the relative strength loss of soil-cement subjected to compaction delay and to develop a numerical tool that can be easily used by engineers and contractors for determining a maximum compaction delay time for a given project. These objectives were addressed through extensive laboratory work and statistical analyses. The laboratory work involved testing an aggregate base material and a subgrade soil, each treated with two levels of cement. Environmental factors included in the experimentation were wind speed, temperature, and relative humidity, and three levels of each were evaluated in combination with varying compaction delay times. The primary response variables in this research were relative compaction and relative strength. The findings indicate that relative strength is sensitive to variability among the selected independent variables within the ranges investigated in this research, while relative compaction is not. Inferring relative strength from relative compaction is therefore not a reliable approach on soil-cement projects. Consistent with theory, higher wind speed, higher air temperature, lower relative humidity, and higher compaction delay time generally result in lower relative strength. With the nomographs developed in this research, the maximum delay time permitted for compaction of either a base or subgrade material similar to those tested in this research can be determined. Knowing in advance how much time is available for working the soil-cement will help contractors schedule their activities more appropriately and ultimately produce higher quality roads. When acceptable compaction delays are not obtainable due to adverse environmental conditions, a contractor may consider using set retarder, mixing at water contents above OMC, or constructing at night as possible solutions for achieving target relative strength values.

In well cementing, the cement slurry is exposed to the conditions far different than those of ordinary Portland cement (PC) used in construction. After placement, hardened cement paste should preserve integrity and provide zonal isolation through the life of the well. American Petroleum Institute (API) Class G cement is the most common cement type used in various well conditions. Class G cement has a high degree of sulfate resistance which makes it more stable than PC when subjected to the compulsive well conditions. Ground granulated blast furnace slag (GGBFS) blended cement has a long history of use in the construction industry, but is not extensively used in well cementing applications. This study presents an experimental program to investigate the applicability of CEM I and GGBFS blended cement pastes in the well cementing industry. Class G cement and blends of CEM I and GGBFS with the proportions (80:20), (60:40), (40:60) and (20:80) are prepared with same water/cement ratio (0.44) as restricted for Class G cement in API Specification 10A to be tested. The cement pastes are cured for ages of 1 day, 7 days and 28 days at 80

In the production of cement, to increase the cement/clinker ratio and decrease CO2 emission, the most important alternative is to produce mineral admixture incorporated cements (CEM II-III-IV-V) instead of portland cement (CEM I). These cements are usually produced by intergrinding the portland cement clinker and the mineral admixtures. However, the difference between grindabilities of the different components of such cements may cause significant effects on the particle size distribution and many other properties. For this reason, separate grinding of additives and clinker may be thought as an alternative. In this study, the effects of intergrinding and separate grinding on the particle size distribution and consequently on the strength of portland composite cements which contained natural pozzolan (trass), granulated blast furnace slag (GBFS) and limestone besides portland cement clinker were studied.