O presente estudo in vitro analisou o efeito de 3 sucos de fruta com baixo pH (suco de cupuaçu, taperebá e laranja), e saliva artificial (controle) sobre materiais restauradores indicados em lesões cervicais não cariosas: resina composta nanoparticulada (Filtek Z350 XT), cimento de ionômero de vidro resino modificado (Vitremer) e um cimento de ionômero de vidro convencional (Fuji II). Os materiais foram avaliados, quantitativamente, quanto à alteração de: peso, rugosidade superficial e microdureza superficial, e qualitativamente, por microscopia eletrônica de varredura (MEV). Foram confeccionados 144 corpos de prova para cada teste quantitativo (n=12) e 45 para o MEV (n=3), de (8mm de diâmetro x 2mm de altura). Os corpos de prova foram preparados, mantidos em saliva artificial por 24 h à 37º C, receberam acabamento em politriz, e em seguida foram realizadas as leituras iniciais. Durante um período de 10 dias consecutivos, os corpos de prova foram submetidos ao desafio erosivo (nos respectivos sucos de frutas) durante 30 minutos três vezes ao dia, totalizando 90 minutos/dia e mantidos em saliva artificial entre os intervalos. Após o período de ciclagem erosiva, foram realizadas as leituras finais. Os resultados obtidos foram submetidos ao teste t, ANOVA e Tukey. As médias de alteração entre os valores de peso finais e iniciais demonstraram diferença significativa (p<0,01) nos materiais estudados e em todos os sucos estudados, com exceção do Vitremer quando imerso no suco de taperebá (p>0,01). As médias de alteração entre os valores de rugosidade superficial final e inicial demonstraram diferença significativa (p<0,01) para todos os materiais estudados em todos os sucos, exceto a Filtek Z350 XT no grupo controle que não apresentou diferença significativa (p>0,01). A comparação entre os valores de microdureza final e inicial demonstrou diferença significativa (p<0,01) na microdureza dos materiais estudados em todos os meios de imersão, inclusive no grupo controle. De um modo geral o suco de taperebá foi o que provocou a maior alteração na superfície dos materiais restauradores quanto ao peso, rugosidade, microdureza e na microscopia eletrônica de varredura. A resina composta Filtek Z350 XT foi o material restaurador que menos sofreu alterações de superfície. Concluiu-se que os sucos das frutas estudados são capazes de alterar os materiais restauradores, sendo que a resina composta foi o material que sofreu menor alteração. / This in vitro study examined the effects of 3 fruit juices with low pH (cupuaçu, taperebá and orange) and artificial saliva (control) upon restorative materials indicated in noncarious cervical lesions: nanoparticle composite resin (Filtek Z350 XT), resin-modified glass ionomer cement (Vitremer) and a glass ionomer cement (Fuji II). The materials were evaluated quantitatively as for alterations in weight, surface roughness and surface microhardness, and qualitatively by scanning electronic microscopy (SEM). 144 specimens were prepared for each quantitative test (n = 12) and 45 for the SEM (n = 3), of (8mm diameter x 2mm height). The specimens were prepared, stored in artificial saliva for 24 hours at 37º C, were finished in a polishing machine, and then the initial readings were performed. During a period of 10 consecutive days, the specimens were subjected to erosive challenge (in the respective juices) for 30 minutes, three times a day, and totaling 90 minutes/day and kept in artificial saliva between intervals. After the erosive cycling period, the final readings were taken. The data were analyzed using t test, ANOVA and Tukey.Test The average alterations between the values of initial and final weight showed significant difference (p < 0.01) in the material studied and all the juices studied, except for Vitremer when immersed in taperebá juice (p > 0.01). The average alterations between the values of initial and final surface roughness showed a significant difference (p < 0.01) for all materials studied in all juices, except for Filtek Z350 XT, in the control group, that showed no significant differences (p > 0.01). The comparison between the values of initial and final microhardness showed a significant difference (p < 0.01) in microhardness of the materials studied in all immersion means, including the control group. In general, taperebá juice was the one that caused the biggest alterations in the surface of restorative materials with respect to weight, roughness, hardness and scanning electronic microscopy. The composite resin Filtek Z350 XT was the restorative material that suffered less surface alterations. It was concluded that the fruit juices studied are capable of altering the restorative materials, and composite resin was the material that has undergone minor changes.

A geração de resíduos sólidos é inerente ao desenvolvimento humano. O concreto armado é um dos materiais mais utilizados pelo homem e tem o cimento Portland como seu principal constituinte, o qual é produzido pela moagem de clínquer e gesso. O clínquer pode ser definido como um mineral artificial, obtido a partir das reações físico-químicas de calcário, argila e corretivos a altas temperaturas, em forno rotativo industrial, mediante a queima de combustíveis fósseis. No início da década de 70 foram realizadas as primeiras experiências de substituição de combustíveis fósseis por resíduos industriais nos Estados Unidos e países europeus, através da técnica denominada co-processamento, resultando na manufatura de um produto ao mesmo tempo em que os resíduos eram eliminados. O co-processamento se baseia na recuperação da energia disponível nos resíduos, substituindo parte daquela fornecida pelos combustíveis tradicionais ou na substituição de matérias-primas por resíduos com características químicas semelhantes àquelas normalmente empregadas na produção do clínquer. No estado de São Paulo as primeiras iniciativas para a utilização de resíduos industriais em fornos de clínquer ocorreram no início da década de 90. A partir de 1997 os órgãos ambientais de alguns estados brasileiros normatizaram procedimentos de licenciamento da atividade que foi, posteriormente, uniformizada por norma em âmbito federal. No ano de 1995 a Companhia de Cimento Ribeirão Grande/SP, Brasil, iniciou os procedimentos visando a substituição parcial dos combustíveis utilizados nos fornos rotativos por uma mistura de resíduos industriais. No período de 1995 a 2002 foram realizadas campanhas de amostragens em chaminés para avaliação das emissões atmosféricas dos dois fornos de produção de clínquer. A análise dos resultados obtidos associada às demais informações disponíveis de monitoramento das características das matérias-primas e combustíveis utilizados, bem como dos produtos finais, clínquer e cimento, não evidenciou alterações significativas nos níveis de emissões atmosféricas, sobretudo de material particulado e óxidos de enxofre, que pudessem ser associadas à utilização dos resíduos. Foram confirmadas as baixas emissões de inorgânicos e evidenciado o papel representado pelos resíduos no aporte dessas substâncias no sistema-forno, concluindo-se que esse aporte pode ser tão ou mais importante pela via da alimentação da farinha, cujos teores estão associados às características das jazidas minerais utilizadas. Foi também confirmada a alta eficiência do sistema-forno na destruição e remoção dos compostos orgânicos perigosos alimentados durante os testes de queima. / The production of industrial residues in inherent to the human development. The cement concrete is one of the most used material, manly the type portland cement, which is constituted by grinding clinker and gypsum together. Clinker can be defined as an artificial mineral obtained by applying physico-chemical reactions, at very high temperatures, to an appropriated mixture of limestone, clay, and some other materials in a rotating industrial kiln wich burns fossil fuels. In the early 1970 decade occurred the first experiences substituting fossil fuels by organic residues in USA and Europe through a technique named co-processing that results the production of certain manufacture while eliminates residues. Co-processing is based in the recovery of thermal energy and/or the mass of some constituents from some residues, with the same chemical characteristics of normal sources of energy, then economizing fuels and mass constituents and making better use of residues, otherwise useless and environmentally polluters. In the state of São Paulo this practice began in early 1990 decade and by 1997 it was started the standardization of the rules for its use in some units of the federation. Later this activity was regulated by nationally approved standard rules. In 1995 the industry Companhia de Cimento Ribeirão Grande (CCRG), a cement plant located in the city of Ribeirão Grande, São Paulo state, Brazil, started procedures searching the partial substitution of the normal fuels by a mixture of industrial residues in its two rotating kilns. The gaseous emissions from the chimneys of these two clinker kilns were studied from 1995 to 2002 about the use of residues as part of the fuel. Analyses of the final results associated with other informations concerning to the quality of raw minerals, fuels and products did not show significant alterations in atmospheric emissions, mainly for particulate material and sulfur oxides, related with the use of residues. The emissions of inorganic continued to be low and not significantly altered by the presence of residues. It was possible to conclude that the alterations in inorganic emissions depend more from the quality of the raw minerals feed in the kilns, which is more difficult to control, than from the presence of residues being burn with the fuel. It was shown a high efficiency in the destruction of dangerous organic compounds feed in the cement kilns, under test conditions.

Orientador: Michael McDonald Hall / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas / O exemplar do AEL pertence a Coleção CPDS / Made available in DSpace on 2018-08-04T03:26:54Z (GMT). No. of bitstreams: 1 Chaves_MarceloAntonio_M.pdf: 6305404 bytes, checksum: e3f6fa0bc74689f8cb5eaf07e7e5c282 (MD5) Previous issue date: 2005 / Resumo: A primeira grande fábrica de cimento do país, inaugurada em 1926, no bairro de Perus, em São Paulo, determina o recorte temático desta dissertação. As circunstâncias de sua instalação, a articulação com outros empreendimentos ¿ indústria de cal e transporte ferroviário -, a produção de uma mercadoria fundamental para a expansão urbana ¿ o cimento - e o singular processo de produção/trabalho da fábrica, introduzem a escrita. Entretanto, o enfoque privilegiado e articulador deste trabalho é a reflexão sobre os diversos aspectos da vida dos trabalhadores da fábrica e das pedreiras, onde o momento da produção e da reprodução da força de trabalho se confundem. Meu trabalho é fundamentado, principalmente, em fontes documentais primárias, destacando-se a exposição, cruzamento e análise de dados extraídos de 1500 fichas de trabalhadores. Assim, procuro identificar as condições de vida e de trabalho das primeiras gerações de trabalhadores da fábrica de cimento, entre os anos de 1925 e 1947: migração e imigração, nacionais e estrangeiros, negros e brancos, grau de instrução, salários, estabilidade no emprego, acidentes de trabalho, entre outros. Além de expor inúmeros dados empíricos que revelam mais detalhes daquele rico período da história do Brasil, nesta pesquisa, tem destaque também a conflituosa e ambígua trajetória de criação do primeiro sindicato dos trabalhadores, em 1933, buscando, através dela, problematizar e ilustrar a não menos ambígua e complexa história dos primeiros momentos de instalação do sindicalismo oficial no Brasil / Abstract: The first great cement factory of Brazil, inaugurated in 1926 in the neighbourhood of Perus, in São Paulo, determines the thematic focus of this dissertation. The circumstances of its construction, its articulation with other enterprises ¿ limestone industry and railroad transport -, the production of a basic element for the urban expansion - cement - and the singular production/work process of the factory open the writing. However, the main focus of this work is a reflection on the diverse aspects of the life of workers from the factory and from the quarries, where the moments of production and of reproduction of the work force blend in with one another. My work is based mainly in primary documentary sources, emphasizing the exposition, comparing and analysis of data extracted from 1500 worker¿s profile records. Thus, I try to identify the life and work conditions of the first generations of workers from the cement factory between the years of 1925 and 1947: migration and immigration; natives and foreigners; black and white; degree of instruction; wages; stability in the job; industrial accidents, among others. Besides displaying innumerable empirical data which disclose more details about that rich period of Brazil¿s history, this research also highlights the conflicting and ambiguous trajectory of the creation of the first workers trade union, in 1933, attempting through that to discuss and illustrate the not less ambiguous and complex history of the first moments of the institution of the official unionism in Brazil / Mestrado / Historia Social do Trabalho / Mestre em História Social do Trabalho

The present investigation is focused on the thermal performance of building materials, specifically their thermal transmittance, and consequent impact on building envelope and building thermal performance. Thermal performance of building materials plays a crucial role in regulating indoor thermal comfort when suitably integrated as part of the building envelope. Studies into thermal performance of building materials are few, particularly in the context of designing building blocks to achieve a particular thermal transmittance in buildings. Such studies require both theoretical (numerical) investigations augmented with experimental investigation into material thermal performance. A unique contribution of this study has been assessing the temperature-dependent performance of building material and their influence on thermal conductivity. The thermal performance of conventional and alternative (low energy) building materials have also been investigated to assess their suitability for naturally ventilated building in salient climatic zones in India. The study has also investigated the impact of varying mix proportions in Cement Stabilized Soil Block on thermal performance. There is little evidence of such studies, involving both experimental and theoretical studies, tracing the thermal performance of building materials to building performance. The current study involves three parts: studying thermo-physical properties of building materials, building-envelope performance evaluation and case-study investigation on buildings in various climatic zones. The thermo-physical study involves understanding the role of materials mix-proportion, composition, and microstructure for its influence on building-envelope thermal performance. Studies into building envelope performance for conventional and alternative building materials, includes, steady and dynamic thermal performance parameters. As part of the study, a calibrated hot-box thermal testing facility has been tested to experimentally determine the thermal performance of building envelopes. Case-study investigation involves real-time monitoring and simulation based assessment of naturally ventilated buildings in three climatic zones of India. The study finds noticeable temperature-dependent performance for various building materials tested. However, their impact on overall thermal performance of buildings is limited for the climatic zones tested. Further, the study validates the hitherto unexplored possibility of customizing building materials for specific thermal performances.

L’objectif de la thèse est de comprendre le comportement géochimique de l’arsenic dans les remblais miniers en pâte cimentés. Cette technique est employée depuis plusieurs années pour remblayer les galeries de mine exploitées à l’aide des rejets de concentrateurs. Pour cette étude, deux types de remblais sont élaborés en laboratoire : des échantillons de remblai minier en pâte synthétiques, fabriqués à partir de silice et enrichis artificiellement en arsenic, et des remblais miniers en pâte élaborés à partir de rejets miniers arséniés. Dans les deux cas, différents liants cimentaires sont testés. Plusieurs types d’investigations sont menés sur les échantillons de remblai en pâte cimentés. Une caractérisation minéralogique est effectuée à l’aide de divers outils. En parallèle, les échantillons de remblais sont soumis à différents tests de lixiviation complémentaires, afin d’évaluer la mobilité/rétention de l’arsenic dans ces matrices. Enfin, une modélisation géochimique est mise en œuvre à partir des résultats issus des deux études précédentes, afin d’affiner les connaissances sur la nature et la stabilité des composés arséniés dans les remblais étudiés. Les résultats obtenus indiquent que l’arsenic est mieux stabilisé dans les matrices à base de ciment Portland et de laitier de haut-fourneau que dans les remblais à base de cendres volantes. Le comportement à la lixiviation variable d’une matrice à l’autre s’explique par des spéciations et des mécanismes de piégeage de l’arsenic variés. L’arsenic peut précipiter sous forme de minéraux arséniés, principalement sous forme d’arséniates de calcium, mais aussi de divers autres composés secondaires variables d’une matrice à l’autre. Un piégeage physique des grains de rejets miniers arséniés par les hydrates cimentaires peut aussi avoir lieu, par formation d’un revêtement limitant l’oxydation des sulfures porteurs d’arsenic. Tous ces mécanismes interviennent dans la stabilisation/solidification de l’arsenic. / The objective of this study is to understand the geochemical behaviour of arsenic in cemented paste backfills. This technique consists in transporting the tailings in the mine openings. Two types of backfills are prepared in the laboratory for this study. First, synthetic cemented paste backfills artificially spiked with arsenic are synthesized, using silica in replacement of the tailings. In parallel, other cemented paste backfill specimens are prepared with arsenic-rich tailings. In the two cases, various types of hydraulic binders are tested. Several types of investigations are conducted on the cemented paste backfill specimens. A mineralogical characterization is carried out with the help of specific tools. At the same time, cemented paste backfill samples are submitted to several complementary leaching tests, to assess the mobility/immobilization potential of arsenic in these matrices. Finally, geochemical modeling is implemented, based on the results of the two previous studies, in order to refine the understanding of the nature and stability of the arsenic compounds. The results show that arsenic is better immobilized in Portland cement and slag-based matrices, rather than in fly ash-based matrices. The variable leaching behaviour from a given matrix to another is due to different arsenic trapping mechanisms. Arsenic can precipitate and form several arsenic minerals, mainly calcium arsenates, but also various other secondary compounds, which are different from a matrix to another. Physical entrapment of the tailings grains by the cementitious minerals can also occur, by formation of a coating around the grains, limiting the oxidation and dissolution of arsenic-bearing sulfides (passivation). These mechanisms are involved in the stabilization/solidification of arsenic by cemented paste backfills.

L’industrie cimentière française possède une influence internationale considérable. L’entreprise Lafarge est aujourd’hui le numéro un mondial du ciment. Ses concurrents français sont tout aussi performants. On peut citer Vicat, entreprise familiale, ou la société Ciment Français, filiale du groupe Heidelberg-Italcementi. Ciments Français est une entreprise héritière du groupe Poliet et Chausson. En 1971, suite au rachat de la branche cimentière de Poliet et Chausson par Ciments Français, les départements des ciments des deux groupes fusionnent. Puis, Poliet et Chausson est transformée en société holding de distribution de matériaux de construction sous le nom de Poliet S.A. Elle est rachetée par Saint Gobain en 1996 et son nom disparaît. La firme a pourtant été la première entreprise française de ciment en 1930. C’est la monographie de cette entreprise que s’attache à retranscrire cette thèse. L’histoire de Poliet et Chausson au cours du XXe siècle est tortueuse. Par un effet d’aubaine, cette entreprise parisienne de matériaux de construction, profite de l’invention du marché du ciment pour devenir l’un des plus grands producteurs de ciment français au cours des années 1930. Sa trajectoire est parallèle à celle de l’entreprise Lafarge. Elle en diffère cependant par bien des points. Émaillée d’embûches, elle oscille entre des moments de succès considérables et des périodes plus troublées. Entre industrialisation et désindustrialisation, l’histoire de Poliet et Chausson s’écrit dans l’ombre de son concurrent plus brillant, Lafarge. Comment expliquer la réussite de l’un et la disparition de l’autre ? / The French cement industry has considerable international influence. Lafarge is now the world's largest cement company. Its French competitors are equally performing. These include Vicat, a family business, or Ciment Français, a subsidiary of the Italcementi group. Ciments Français is a company inheriting from the group Poliet and Chausson. In 1971, following the purchase of the cement sector of Poliet and Chausson by Ciments Français, the cement departments of the two groups merged. Then Poliet and Chausson was transformed into a holding company for the distribution of building materials under the name Poliet S.A. It was bought by Saint Gobain in 1996 and its name disappeared. The firm was, however, the first French cement company in 1930. This thesis attempts to transcribe the monography of Poliet and Chausson. The history of Poliet and Chausson during the twentieth century is tortuous. Through a windfall effect, this Parisian company of building materials, profits from the invention of the cement market to become one of the largest producers of French cement in the 1930s. Its trajectory is parallel to that of the Lafarge company. However, it differs in many aspects. It is fraught with obstacles, and oscillates between moments of considerable success and more troubled periods. Between industrialization and desindustrialization, the story of Poliet and Chausson is written in the shadow of its brighter competitor, Lafarge. How can we explain the success of the one and the disappearance of the other?

Aujourd'hui, les problèmes environnementaux sont plus graves que jamais. Des mesures urgentes devraient être prises dans tous les domaines de l'activité humaine, y compris la construction. L'un des principaux contributeurs à l'impact négatif de cette industrie sur l'environnement est la fabrication du ciment Portland ordinaire (OPC) nécessaire à la production de béton et d’autres matériaux cimentaire. Malgré son importance, il présente un inconvénient important: sa production est accompagnée par de grandes quantités de gaz à effet de serre. Ils représentent 5 à 8% des émissions mondiales totales de CO2. Des matériaux cimentaires plus écologiques sont maintenant nécessaires.Des réductions significatives de l’impact sur l’environnement ne peuvent être obtenues que par l’utilisation de liants de nouvelle génération dont la fabrication ne nécessite pas beaucoup de processus et de traitements supplémentaires. L'une d'elles consiste à utiliser des déchets industriels comme liants (différentes laitiers, cendres volantes, cendres de biomasse, etc.). De cette manière, il y a non seulement une réduction de l'impact de processus tels que l'extraction minière ou la calcination, mais également le recyclage des déchets (un principe de l'économie circulaire).Une possibilité consiste à utiliser du laitier de haut fourneau (GGBS) comme base pour ce ciment de nouvelle génération. En raison de sa réactivité relativement faible avec l'eau, des suppléments (également appelés activateurs) doivent être utilisés pour favoriser le processus d'hydratation. Le carbonate de sodium (Na2CO3) est l’un des activateurs les plus prometteurs et en même temps les moins étudiés. Un tel ciment alkali-activé présente des propriétés mécaniques et de durabilité élevées, ainsi qu'une empreinte CO2 très faible. Parmi les principaux problèmes qui entravent son utilisation à l'échelle industrielle, on peut mentionner une évolution de la résistance lente à jeune âge et de rhéologie médiocre.L'objectif de la présente thèse est de développer une nouvelle conception du liant à base de laitier activé par Na2CO3, qui répondrait à toutes les exigences modernes du secteur de la construction, en particulier les propriétés rhéologiques et le développement de la résistance à jeune âge. Ce liant doit toujours répondre à au moins trois critères principaux: faible impact environnemental, faibles risques de danger dans les applications sur le terrain et être économiquement compétitif à l'échelle industrielle.Dans le présent travail, l’influence de différents paramètres tels que le rapport eau/liant, la concentration de Na2CO3, la finesse du laitier et les conditions de durcissement sur les propriétés du mélange à jeune âge et à long terme a été étudiée. Sur la base des résultats du processus d’hydratation, les additifs à base de phosphonate qui permettent de contrôler efficacement la rhéologie de tels liants ont été testé avec succès. Ils permettent non seulement de contrôler le temps de prise, mais fournissent également un effet plastifiant.En ce qui concerne l’amélioration des propriétés de résistance au jeune âge, différentes méthodes ont été utilisées. L’utilisation d’un traitement thermique ou d’une augmentation de la finesse du GGBS s’est avérée efficace. L’exploration des causes d’une longue période d’induction a montré que l’accélération pouvait également être obtenue par l’ajout d’une source de calcium à cinétique de dissolution contrôlée. En conséquence, le liant est devenu plus réactif et plus robuste à certains facteurs (concentration d’activateur, rapport eau/liant, conditions de durcissement, etc.). Pour compenser l'empreinte carbone supplémentaire de la source de calcium ajoutée, le liant a été dilué avec succès par le calcaire sans aucune dégradation des propriétés à un certain pourcentage de dilution. / Today, environmental problems are more acute than ever. Urgent measures should be taken in all spheres of human activity including construction and civil engineering. One of the major contributors of negative environmental impacts from this industry is the manufacturing of ordinary Portland cement (OPC) required for concrete and other cementitious materials production. Although its importance to economical development, it has a significant drawback - its production is accompanied by the emission of large quantities of greenhouse gases. They account for 5-8% of total world CO2 emissions. More environmentally friendly cementitious materials are now required.Significant reductions of the environmental impact can be achieved only through the use of new-generation binders whose manufacture does not require a lot of additional processes and treatments. One route is through the use of industrial wastes as binders (different slags, fly ash, biomass bottom ash, etc.). In this way there is not only a reduction in the impact of processes such as mining or calcination, but also the recycling of waste materials (circular economy principle).One possibility is to use ground granulated blast furnace slag (GGBS) as the basis for such a new generation cement. Due to its rather low reactivity with water, additional supplements (also called activators) should be used to promote the hydration process. One of the most promising, and at the same time least studied, activators is sodium carbonate (Na2CO3). Such alkali-activated cements present high mechanical and durability properties, as well as a very low CO2 footprint. Among the main problems hindering its industrial scale adoption are their poor rheology and too slow strength gain within the first days of hardening.The objective of the present thesis is to develop a new binder based on Na2CO3 activated GGBS that would meet all the modern requirements of the construction industry, in particular regarding the rheological properties and early age strength development. In addition this binder should always respond to at least three main criteria: low environmental impact, low health and safety concerns in field applications, and be economically competitive at industrial scale.In the present work, the influence of different parameters like water/binder ratio, Na2CO3 concentration, slag fineness and curing conditions on both early age and long term properties of the mixture were studied. Based on the results of the hydration process analysis, phosphonate based additives that allow for the effective control of the rheology of such binders were successfully tested. They not only allow control over the setting time, but also provide a plasticizing effect.Regarding the improvement of early age strength properties, various methods have been used. The use of heat treatment or an increase of GGBS fineness turned out to be efficient. Exploring the causes of the long induction period has shown that acceleration can also be achieved by the addition of a calcium source with controlled dissolution kinetics. As a result, the binder became more reactive and robust against certain factors (activator concentration, Water/Binder ratio, curing conditions, etc.). To compensate for the additional carbon footprint from the added calcium source, the binder was successfully diluted by limestone without any degradation of the properties below some dilution percentages.

The diploma thesis deals with the determination of the influence of the maximum density of the cement matrix on the volume changes of concrete, the influence of different admixtures or their combinations on the development of hydration temperatures and on the water separation of concrete. The theoretical part describes the various types of volume changes of concrete, the effects of individual input components and mineral admixtures on water separation, hydration heat development and concrete microstructure. The experimental part is focused on monitoring not only the volume changes of concrete mixtures made using different types of admixtures or their suitable combination until the age of 60 days of maturation, but also the influence of their use on selected mechanical parameters of concrete such as compressive strength, concrete in its fresh state and monitoring changes in the microstructure from long-term aging mixtures.

This study evaluates question of alkali–silica reaction (ASR) in hybrid system, which was designed in the bachelor's thesis, to meet the requirements of EN 197-1 and classified to the Blastfurnace CEM III/C cements. The durability of this system is a great unknown. For this reason, the same methods (ASTM C1260, ASTM C289 and ASTM C856) were used to observer the ASR effects as the ones used to observer the Portland cement based concrete. Supplementary methods include determination of compressive strengths according to EN 196-2 and scanning electron microscopy to observe the microstructure. Hybrid system results were compared to two different types of cements, CEM I and CEM III/B. From the results of the ASR evaluation assays, it was found that the hybrid system (CEM III/C-HB) and CEM III/B showed the lowest tendency to ASR. The results of the supplementary methods showed that CEM III/C-HB compressive strength increases after 14 days within NaOH by 43 % in comparison to 28 days strength. Based on those results, it is sure that the CEM III/C-HB shows little susceptibility to ASR.

Nowadays, the waste sands from the water glass production have no utilization and due to high alkali content are considered as a dangerous waste. So the aim of this thesis is to find and study some possibilities of their utilization in the building industry. First of all, some necessary analysis of these sands were performed and then some advantages and disadvantages of their application for production of materials based on portland cement and alkali activated materials were studied. Characteristics of fresh and hardened pastes, mortars and concretes containing these waste sands were determined. The most tested properties were their workability and their compressive and flexural strength. Close attention for the risks of alkali-silica reaction and for options of its suppressing by the mineral admixtures was paid.