Submitted by Ronildo Prado (ronisp@ufscar.br) on 2017-08-17T14:39:42Z No. of bitstreams: 1 DissTRR.pdf: 2739559 bytes, checksum: 80c76b7b0d4fcf15e1c9962556cd8745 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-17T14:39:52Z (GMT) No. of bitstreams: 1 DissTRR.pdf: 2739559 bytes, checksum: 80c76b7b0d4fcf15e1c9962556cd8745 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-17T14:39:58Z (GMT) No. of bitstreams: 1 DissTRR.pdf: 2739559 bytes, checksum: 80c76b7b0d4fcf15e1c9962556cd8745 (MD5) / Made available in DSpace on 2017-08-17T14:40:04Z (GMT). No. of bitstreams: 1 DissTRR.pdf: 2739559 bytes, checksum: 80c76b7b0d4fcf15e1c9962556cd8745 (MD5) Previous issue date: 2017-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The frailty models are used to model the possible associations between survival times. Another alternative developed for modeling the dependence between multivariate data is the use of models based on copulas functions. In this paper we propose two derived survival models of copula of the Ali-Mikhail-Haq (AMH) and of the Frank to model the dependence of bivariate data in the presence of covariates and censored observations. For inferential purposes, we conducted a Bayesian approach using Monte Carlo methods in Markov Chain (MCMC). Some discussions on the model selection criteria were presented. In order to detect influential observations we use the Bayesian method of cases of deletion of influence analysis based on the difference ^. Finally, we show the applicability of the proposed models to sets of simulated and real data. We present, too, a new survival model with bivariate fraction of healing, which takes into account three settings for the latent activation mechanism: random activation, first activation and final activation. We apply this model to a set of Direct Credit loan data to the Consumer mode (DCC) and compare the settings, through Bayesian criteria for selection of models, which of the three models best fit. Finally, we show our future proposal for further research. / Os modelos de fragilidade são utilizados para modelar as possíveis associações entre os tempos de sobrevivência. Uma outra alternativa desenvolvida para modelar a dependência entre dados multivariados e o uso dos modelos baseados em funções cápulas. Neste trabalho propusemos dois modelos de sobrevivência derivados das copulas de Ali-Mikhail-Haq (AMH) e de Frank para modelar a dependência de dados bivariados na presença de covariáveis e observações censuradas. Para fins inferenciais, realizamos uma abordagem bayesiana usando métodos Monte Carlo em Cadeias de Markov (MCMC). Algumas discussões sobre os critérios de seleção de modelos são apresentadas. Com o objetivo de detectar observações influentes utilizamos o método bayesiano de analise de influencia de deleção de casos baseado na divergência. Por fim, mostramos a aplicabilidade dos modelos propostos a conjuntos de dados simulados e reais. Apresentamos, também, um novo modelo de sobrevivência bivariado com fração de cura, que leva em consideração três configurações para o mecanismo de ativação latente: ativação aleatória, primeira ativação e áltima ativação. Aplicamos este modelo a um conjunto de dados de empréstimo de Credito Direto ao modo do Consumidor (DCC) e comparamos os ajustes por meio dos critérios bayesianos de seleção de modelos para verificar qual dos três modelos melhor se ajustou. Por fim, mostramos nossa proposta futura para a continuaçaão da pesquisa.

Divine healing has been often seen in opposition to human healing. The two spheres, have been considered as separate, both in space and in terms of elements involved. Asclepian sanctuaries have been mostly presented as domains of exclusively divine intervention, without any involvement of the human factor, possibly with the sole exception of dream interpretation. However, the written testimonies of temple cures, both those in the form of cure inscriptions dedicated in sanctuaries and the literary accounts of the incubation experience, give us reasons to suppose that the practical side of the functioning of the asklepieia could have assumed the involvement of human medicine, with the extent of this involvement differing in various epochs. Regardless of physicians' participation or its lack in the procedure, the methods applied in sanctuary healing appear to have evolved in parallel to the developments in medicine and their popular perception. Archaeological finds as well as the image of Asclepius as the god of medicine itself seem to confirm this. Nevertheless, by no means should these connections between the two spheres be treated as transforming the space of religious meaning into hospitals functioning under the auspices of a powerful god. Although acknowledging them does entail inclusion of human medicine within the space dedicated to Asclepius, it does not thereby deny the procedure of incubation its religious and metaphysical dimension. On the contrary, it shows that to the Greek mind divine and human healing were not mutually exclusive, but overlapped and coincided with each other, proving that the Greek sense of rationality was quite different from the modern and could comprise far more than what we call today "scientific thinking".

Orientador: Rogério Antonio Oliveira / Resumo: A cirrose é uma doença hepática assintomática que, muitas vezes, é descoberta quando o quadro é irreversível. Por isso, o tratamento consiste em uma série de medidas para controlar o avanço da enfermidade, visto que a principal consequência da cirrose é o aumento da pressão na veia portal, que por sua vez, acarreta no surgimento de varizes e no seu respectivo rompimento, podendo ser fatal. Estudos relacionados à esta doença são muito importantes, pois a análise estatística é uma ferramenta que permite auxiliar na tomada de decisões nos procedimentos médicos e acompanhamento de pacientes. Um método estatístico bastante explorado nas ciências biomédicas é a análise de sobrevivência, que consiste em descrever o tempo de um evento inicial até a ocorrência de um outro de interesse. No entanto, existem situações em que uma proporção da amostra não vivencia o desfecho de interesse, mesmo que acompanhado por um período longo de tempo. Nestes casos, tais observações são dita imunes ao desfecho de interesse e as metodologias tradicionais de análise de sobrevivência não são indicadas. Logo, os modelos de fração de cura ou de longa duração, desenvolvido a partir do modelo de mistura, são os utilizados nestas situações. Neste trabalho diverso modelos foram considerados para analisar os tempos de vida de pacientes submetidos à Ligadura Elástica de Varizes Esofágicas, ao qual foram anotados os tempos até o óbito durante o acompanhamento de 129 pacientes do Hospital das Clínicas da Faculdade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Cirrhosis is an asymptomatic liver disease that is often discovered when the patient's condition is irreversible. Therefore, the treatment consists of a series of measures to control the progression of the disease, since the main consequence of the cirrhosis is the increase of the portal venous pressure, which causes the appearance of varices and their respective rupture may be fatal. Studies related to that disease are very important, so the statistical analysis is a tool that helps to make decisions in medical procedures and patient follow-up. The most applied statistical method in the biomedical sciences is survival analysis, which consists of describing the time of occurrence until the event of interest. However, there are situations in which a proportion of the sample does not experience the interest outcome, even if they are accompanied by a long period of time. In such cases, such observations are said to be immune to the outcome of interest and traditional survival analysis methodologies are not appropriated. Therefore, the care fraction or long duration models can be used in these situations because they incorporate mixtures of models to solve the complexity inherent in the actual study. In this work, some statistical models were considered to analyze the survival times of patients, after surgery of Endoscopic Band Ligation of the Esophageal Varices, such as Exponential, Gamma and Weibull models. The data is related to survival times of 129 patients, who were treated... (Complete abstract click electronic access below) / Mestre

La prescription médicamenteuse est l’un des principaux outils thérapeutiques utilisé par le médecin. Si la médecine somatique décline sa clinique selon l’enchaînement symptômes- diagnostic-traitement, la psychiatrie se démarque d’une telle linéarité. En effet, bien qu’elle se soit calquée sur le modèle médical depuis la découverte des psychotropes en 1952, elle relève d’une clinique spécifique : en psychiatrie, d’une part le symptôme constitue une adresse à l’Autre, il contient donc une dimension relationnelle essentielle, d’autre part, le soin psychique implique une participation active du sujet, toute thérapie étant aussi auto-thérapie. La neuropharmacologie, en plein essor depuis 1952, propose un schéma thérapeutique se voulant plus scientifique car de plus en plus éloigné de la psychopathologie clinique. Le psychiatre est alors convoqué en tant que technicien de la prescription de psychotropes, le médicament se suffisant à lui-même d’un point de vue thérapeutique. Face à une telle évolution de la psychiatrie, comment préserver un abord clinique ?Notre pratique esquisse la possibilité de dégager l’acte de prescrire d’une technicité exclusive. En effet, sous certaines conditions, la prescription de psychotropes constitue un acte psychothérapeutique à part entière. Pour cheminer dans notre réflexion, nous sommes passés par le paradigme du pharmakon afin de complexifier la question du prescrire. La clinique suggère une possible alliance entre parole et médicament. Prescrire dans la parole, au-delà de la molécule, consiste à qualifier la substance par la parole, de façon à ce qu’elle devienne un médicament spécifique de la rencontre clinique. La molécule, guidée par la magie des mots, sera plus efficace. L’acte de prescrire se conçoit donc comme une création à deux, à réinventer à chaque nouvelle rencontre, le moment de la prescription relevant d’un cheminement intime du côté du clinicien. Ainsi, loin de s’exclure mutuellement, psychothérapie analytique et pharmacothérapie ont tout intérêt à croiser leurs regards sur la question du prescrire. Penser conjointement effet pharmacologique et relation clinique permet au clinicien de s’engager dans une authentique rencontre humaine avec le patient. La psychopathologie s’ouvrira, peut-être, sur de nouvelles perspectives thérapeutiques. / Prescribing medication is one of the main therapeutic tools used by physicians. If somatic medicine clinically acts according to a 'symptom-diagnosis-treatment' model, psychiatry does not follow this linear pathway. Although it has copied the medical model since the discoveryof psychoactive drugs in 1952, it possesses a specific clinical approach. First of all, in psychiatric care, the symptom is an address to the Other, it contains an essential social dimension. Moreover, it implies the subject's active participation, each therapy also being a self-therapy. Neuropharmacology, in full expansion since 1952, has taken a therapeutic scheme aiming at more scientificity by moving away from clinical psychopathology. Hence psychiatrists are seen as technicians of psychoactive drugs prescription, drugs being considered as self sufficient therapeuticaly. With regard to this evolution in psychiatric care, how can a clinical approach be maintained ? In practice, the act of prescribing can free itself from being exclusively technical. Prescribing psychoactive drugs can indeed, under certain conditions, be a true psychotherapeutic act. To guide us through this reflection, we used the pharmakon paradigm to make the issue of prescribing more complex. Clinical practice suggests a possible alliance between patients'words and medication. Beyond molecular action, prescribing through talking qualifies the substance by words, so it becomes a clinical-interaction-specific drug. The molecule, guided by the magic of words, will be more efficient. The act of prescribing is thus conceived as a creation made possible by two people, that must be reinvented at each encounter. The moment for prescribing is rather the fruit of the clinician intimate decision process. Thus, far from excluding each other, analytical therapy and pharmacotherapy would gain much from sharing their views on the issue of prescribing. Integrating both the pharmacological effect and the clinical interaction would allow clinicians to engage in an authentic human encounter with patients. Psychopathology may then open up to new therapeutic perspectives.

A busca por novas soluções técnicas que, de modo sustentável, diminuam o tempo de construção de obras de engenharia e as tornem mais econômicas, tem tomado, cada vez mais, as linhas de pesquisa do grupo de Engenharia Geotécnica da Universidade Federal do Rio Grande do Sul, onde já foram realizadas inúmeras pesquisas para estudar e compreender o comportamento de solos artificialmente cimentados. O cimento Portland é mundialmente utilizado no melhoramento da resistência e da deformabilidade dos solos, outrora impróprios para utilização. Para estudar a contribuição da cimentação para altas tensões de confinamento, foi construído um equipamento triaxial com capacidade de atingir 10 MPa de tensão confinante que permite o estudo do comportamento tensão-deformação-dilatância de solos artificialmente cimentados curados sob tensão. Juntamente, foi realizado um estudo um numa areia fina e uniforme, artificialmente cimentada, para três tempos de cura (3, 7 e 28 dias), da resistência à compressão simples (qu) e da resistência à compressão diametral (qt) em função da razão vazios/cimento (η/Civ). Os resultados mostraram que a resistência aumenta com a redução da relação vazios/cimento (η/Civ) e com o aumento do tempo de cura (t), sendo que a relação tração/compressão (qt/qu) é independente do tempo de cura e apresenta um valor médio de 0,15. Além dos resultados proferidos, outras misturas de solos granulares com diferentes tipos de cimento, variados tempos de cura, foram analisados e normalizados, obtendo-se uma curva única em que a resistência à compressão simples (qu) e a resistência à compressão diametral (qt) foram normalizadas e estão em função da relação vazios/cimento (η/Civ). Paralelamente pretendeu-se verificar qual o efeito do tipo de cura (sob tensão ou atmosférica) em misturas cimentadas com a realização de ensaios para tensões efetivas médias desde 250 kPa até 4000 kPa. Além disso, avaliou-se a variação do η/Civ e do tempo de cura para amostras curadas sob tensão. Os resultados mostram que, de um modo geral, com o aumento da tensão efetiva média, o tipo de cura não afeta os valores das tensões de desvio máximas. A parcela friccional tem uma predominância no comportamento tensão-deformação. O tipo de cura tem influência na definição da superfície de plastificação e da rigidez, verificando-se o aumento destas propriedades para amostras curadas sob tensão em relação a amostras curadas sob pressão atmosférica. Com base nos resultados obtidos nesta pesquisa, um modelo elasto-plástico com degradação da rigidez, que tem como parâmetros a resistência a compressão simples (qu), ângulo de atrito (ϕ’) e uma deformação equivalente (εs 0,7), foi proposto para simular o comportamento tensão-deformação de misturas de areias artificialmente cimentados em ensaios triaxiais, apresentando resultados satisfatórios. / The search for new technical solutions to reduce construction time of engineering works and to make them more cost-effective has been object of the research lines of the group of Geotechnical Engineering of Federal University do Rio Grande do Sul. Numerous studies have been conducted to analyse and understand the behaviour of artificially cemented. Portland cement is widely used for improving strength and deformability characteristics of soils. To study the contribution of cementation under high pressures, a 10 MPa confining pressure triaxial apparatus was built to study the stress-strain-dilatancy behaviour of artificially cemented soils cured under stress. In parallel a study was conducted on a artificially cemented uniform sand at three curing times (3, 7 and 28 days) to determine the unconfined compressive strength (qu) and splitting tensile strength (qt) according to voids/cement ratio (η/Civ) dosage methodology. The results showed that strength increases with the reduction of voids/cement ratio (η/Civ) and with the increasing of cure time (t). The tensile/compression ratio (qt/qu) is independent of curing time and presents a mean value of 0.15. In addition to these results, other granular soils mixtures with distinct types of cement and different curing times were analysed. A unique normalized curve was fit to unconfined compressive strength (qu) and splitting tensile strength (qt) against voids/cement ratio (η/Civ). At the same time, the effect of the curing type (under stress or atmospheric) was verified through triaxial compression tests with mean effective stresses ranging from 250 kPa to 4000 kPa. In addition, the variation of η/Civ and cure time was evaluated for samples cured under stress. The results show that, in general, by increasing the mean effective stress, the type of cure does not affect the values of the maximum deviatoric stress. The frictional portion is predominant in the stress-strain behavior. The type of cure affects the yielding surface and the stiffness of the samples. It was observed the increase in this properties for samples cured under stress compared to samples cured with atmospheric stress. Based on the outcomes of this study, with satisfactory results, an elastoplastic model with stiffness degradation (using unconfined compressive strength (qu), friction angle (’) and an equivalent strain (  s0.7)) was proposed to simulate the stress-strain behaviour of artificially cemented sands in triaxial tests.

Dans une démarche de valorisation des déchets, les granulats recyclés sont introduits dans la formulation des bétons pour donner naissance à de nouveaux bétons recyclés qui représentent l’objet du projet national RECYBETON et du projet ANR ECOREB. Cette thèse se concentre sur l’étude du béton frais et en particulier la maîtrise du retrait plastique et l’effet du degré de saturation initial des gravillons recyclés sur le comportement des bétons recyclés. Deux familles de bétons avec des rapports eau/ciment respectifs de 0,6 et 0,45 ont été testés en conditions endogènes ainsi qu’en dessiccation (Vvent = 8 m/s). Chaque famille de bétons est constituée d’un béton naturel de référence et de deux bétons recyclés différenciés pas le degré initial de saturation des gravillons recyclés (50 et 120 % de l’absorption nominale). Les résultats expérimentaux soulignent la capacité des gravillons recyclés initialement partiellement saturés à capter rapidement l’eau contenue dans la pâte de ciment, modifiant ainsi le rapport E/C, les propriétés rhéologiques du béton frais et les résistances mécaniques du béton durci. Après saturation en eau, si les conditions de séchage conduisent à un manque d’eau dans le béton, les gravillons recyclés peuvent fournir de l’eau à la pâte. Ils constituent donc un potentiel de cure interne. Le retrait plastique sous vent est explicitement lié au ressuage, au développement de la pression capillaire et à la fissuration. Le temps d’initiation de la fissuration dépend de la quantité d’eau totale dans le béton et de sa capacité à ressuer tandis que l’ouverture de fissure varie avec la valeur de retrait plastique mesurée. Dans cette étude, le développement de la pression capillaire est la cause de la fissuration qui apparaît dès l’entrée d’air dans le matériau poreux. Les différences de comportements les plus importantes sont observées entre bétons ayant une quantité d’eau totale différente plutôt qu’entre bétons naturel et recyclé. La compilation des résultats expérimentaux a permis de mettre sur pied des modélisations qui illustrent les comportements observés. Les pores concernés par l’entrée d’air dans les bétons recyclés et naturels au moment de la fissuration sont les plus gros pores de la pâte. Enfin, un couplage hygrothermique séchage-température du béton peut influer sur le démarrage de l’hydratation. / In the context of sustainable development, the reuse of construction and demolition waste is necessary to conserve nonrenewable natural aggregate resources, so recycled aggregates are introduced in concrete mix design. This is the aim of the national projet RECYBETON and the research project ECOREB. This study deals with the fresh concrete and more specifically with shrinkage control and the effects of the initial saturation degrees of recycled coarse aggregates on concrete behavior.Two concrete families, with two different water/cement ratios 0,60 and 0,45, are tested under endogenous and drying (wind speed equal to 8 m/s) conditions. Each concrete family contains a reference natural concrete and two recycled concretes. The initial saturation degree is the difference between them (recycled coarse aggregates saturated or semi saturated).Experimental results underline the capacity of non-saturated aggregates to quickly absorb water from cement paste, modifying the W/C ratio, rheological properties of the fresh concrete and the mechanical strength (at 28 days) of recycled concretes. After saturation in water, recycled aggregates can release water into the cement paste if the undergone drying conditions lead to a lack of water in the cement matrix. The recycled coarse aggregates can be seen as an internal curing potential.Experimental plastic shrinkage studies carried out under drying conditions highlight a link between bleeding, capillary pressure, plastic shrinkage and cracking. It should be pointed out that the initial cracking is dependent on the total quantity of water in the concrete and on its bleeding capacity. The opening cracks vary with the plastic shrinkage values measured during the test. The analysis of the results emphasize that the capillary pressure is the determining parameter and that the air entry value matches the cracks. The major behavior differences are found between concretes with different volumes of water rather than between natural and recycled concretes.Finally, the analysis of all the experimental results have allowed concrete modelling and understanding why concretes do not behave in the same way. When it cracks, the air come in the biggest pores of the concrete paste. Moreover, a hygrothermal coupling exists between the drying and the temperature in concrete. It can affect hydration start up.

Despite the success illness novels have acquired in the last decade, the misrepresentation of chronic illness in the Young Adult genre is still going unnoticed. In an ableist society that still needs to be educated about invisible disabilities, most of the contemporary YA writers insist on finding miraculous solutions and questionable happy endings to their stories. The aim of this thesis is therefore to study the different ways in which YA writers fetishize and understate invisible disability and to find a way to subvert it. By focusing on the miracle cure trope and romanticization in the case of Nicola Yoon’s Everything Everything, it attempts to highlight the characteristics of low-quality disability fiction and demonstrate why and how the use of disability biases can affect negatively both disabled and nondisabled young readers. In addition, through the scrutiny of the author’s first YA novel, Nothing Wrong with Snails, it then illustrates how the in-depth analysis of past disability literature improved the author’s personal craft and enabled them to portray chronic illness and invisible disability avoiding stereotypes, biases, and tropes. In conclusion, it argues that writers ought to rely on disability studies in order to reach higher standards in the representation of invisible disability in YA fiction.

O objetivo desta investigação foi analisar o universo daqueles indivíduos internados na Santa Casa de Misericórdia de Porto Alegre entre os anos de 1843 e 1872 com o diagnóstico de "alienação mental", ou outro análogo. Para isso, examinei a regulamentação da cidade através das funções normativas e fiscalizadoras da Câmara Municipal e do Código de Posturas. Fiz uma leitura das discussões dos parlamentares provinciais acerca do trato com os inválidos e os vadios, e procurei traçar o perfil da população da capital rio-grandense, cidade escravista e hierarquizada. A Santa Casa, especialmente a partir da criação do seu Asilo de Alienados, foi apresentada como locus principal de recolhimento desses indivíduos, numa atuação muitas vezes associada ao poder policial. Políticas que envolviam a caridade e o controle dos grupos sociais marginalizados, nos quais cativos, libertos e pobres eram os alvos preferenciais. Nesse sentido, ficou evidente que os confinamentos muitas vezes se apresentavam como repressão ao não-trabalho e aos indivíduos insubmissos. Por outro lado, a definição do que era loucura implicava em diferentes níveis de prevalência dos diagnósticos dos médicos. As variações entre as concepções acadêmicas, o entendimento popular sobre as artes de curar e as disputas entre os médicos e as diversas instâncias de poder - como a policial e a judicial - foram aspectos considerados nas observações dos episódios de confinamento. Finalmente, por se tratar de uma sociedade escravista, e a ainda que as fontes analisadas não permitissem uma resposta aprofundada, busquei o entendimento possível sobre a circulação das concepções de africanos e seus descendentes a respeito da doença e da cura. / The objective of this research was to analyze the universe of those interned at the Santa Casa de Misericordia de Porto Alegre between the years of 1843 and 1872 with a diagnosis of "mental alienation", or other analogue. For this, examined the regulation of the city through the regulatory and supervisory functions of the City Council and the Code of Posturas. I have read the discussions of the provincial parliamentarians about the deal with the invalid and idles and I tried to draw the profile of the population from Porto Alegre, proslavery and hierarchical city. The Santa Casa, especially from the creation of its Asylum of Alienated, was presented as a main locus of collection of these individuals, in a performance often associated with the police power. Policies involving the charity and control of marginalized social groups, in which captives, and poor freed were particularly targeted. Thus, it was clear that confines often presented as if the prosecution does not-work and unsubmissive individuals. Moreover, the definition of what was meant madness on different levels of prevalence of diagnoses of doctors. The variations between the academic ideas, the popular understanding of the arts to heal and disputes between doctors and the various bodies of power - such as Police and Justice - aspects were considered in the remarks of episodes of confinement. Finally, as a proslavery society, and even if the sources analyzed not allow a response depth, sought the understanding on the possible movement of conceptions of Africans and their descendants about the disease and cure.

Actuellement, il est largement reconnu que la durabilité des structures en béton armé, due à la corrosion des armatures engendrée par la carbonatation ou la pénétration des chlorures, peut être affectée largement par les conditions de cure et de serrage du béton coulé en place. Toutefois, les effets de ces conditions sur la qualité du béton ne sont pas encore entièrement comprises, puisqu'elles sont habituellement négligées (ou traitées superficiellement) dans les méthodologies actuelles de performance utilisées pour la spécification et contrôle de sa durabilité. Dans ce travail sont étudiés les effets des conditions habituelles de mise en place (y compris le serrage) et cure sur les propriétés de durabilité du béton, à savoir, la résistance à la carbonatation accélérée, le coefficient de migration des chlorures (dans des conditions non stationnaires), l'absorption d'eau et la perméabilité aux gaz (méthode CEMBUREAU). À cette fin, plusieurs bétons de différent composition, sans et avec cendres volantes, ont été soumis à deux principaux programmes expérimentaux. Dans le premier programme, trois bétons ont été soumis à une cure humide dans le laboratoire à différentes températures, entre 5 °C et 60 °C, et testés à différents âges, entre 28 et 182 jours, pour quantifier l'effet isolé de la température de cure sur les propriétés de durabilité du béton. Dans le deuxième programme, plusieurs éléments (dalles, poutres et poteaux) ont été coulés sur chantier, pendant l'hiver et l'été, après avoir été soumis à deux conditions différentes de serrage, vibré et non vibré, et démoulés à différentes à 24 h et 72 h. Les propriétés de durabilité du béton près de la surface et de cœur des éléments (propriétés réelles) ont ensuite été mesurées à différents âges, entre 28 et 364 jours, et comparées avec les propriétés des échantillons vibrés et curés en conditions normalisées (propriétés potentielles). / It is widely recognized that the long-term durability of reinforced concrete structures related to carbonation- and chloride-induced corrosion can be detrimentally affected by on-site placing and curing conditions of concrete. However, the effects of these conditions on concrete durability are still not fully understood, being usually overlooked in current performance-based specifications and control of concrete durability. In this work, the effects of realistic placing (including compaction) and curing conditions on the concrete durability-related properties most used in performance-based specifications are studied, such as the accelerated carbonation resistance, chloride migration coefficient (non-steady state conditions), water absorption and gas permeability (CEMBUREAU method). For that purpose, several concretes of different composition, with and without fly ash addition, were subjected to two main experimental programs. In the first program, the concretes were cured in the laboratory under several temperature regimes, ranging from 5 ºC to 60 ºC, and then tested at different ages, from 28 to 182 days, in order to evaluate the isolated effect of curing temperature on their durability-related properties. In the second program, several concrete elements (slabs, beams and columns) were cast outdoors, during the winter and summer, and subjected to different compaction (vibrated and not vibrated) and curing (demoulded after 24 h and 72 h) conditions. The durability-related properties of the inner and outermost concrete of the elements (actual properties) were then measured at different ages, from 28 to 364 days, and compared with those of standard specimens made of the same concrete (potential properties).

A busca por novas soluções técnicas que, de modo sustentável, diminuam o tempo de construção de obras de engenharia e as tornem mais econômicas, tem tomado, cada vez mais, as linhas de pesquisa do grupo de Engenharia Geotécnica da Universidade Federal do Rio Grande do Sul, onde já foram realizadas inúmeras pesquisas para estudar e compreender o comportamento de solos artificialmente cimentados. O cimento Portland é mundialmente utilizado no melhoramento da resistência e da deformabilidade dos solos, outrora impróprios para utilização. Para estudar a contribuição da cimentação para altas tensões de confinamento, foi construído um equipamento triaxial com capacidade de atingir 10 MPa de tensão confinante que permite o estudo do comportamento tensão-deformação-dilatância de solos artificialmente cimentados curados sob tensão. Juntamente, foi realizado um estudo um numa areia fina e uniforme, artificialmente cimentada, para três tempos de cura (3, 7 e 28 dias), da resistência à compressão simples (qu) e da resistência à compressão diametral (qt) em função da razão vazios/cimento (η/Civ). Os resultados mostraram que a resistência aumenta com a redução da relação vazios/cimento (η/Civ) e com o aumento do tempo de cura (t), sendo que a relação tração/compressão (qt/qu) é independente do tempo de cura e apresenta um valor médio de 0,15. Além dos resultados proferidos, outras misturas de solos granulares com diferentes tipos de cimento, variados tempos de cura, foram analisados e normalizados, obtendo-se uma curva única em que a resistência à compressão simples (qu) e a resistência à compressão diametral (qt) foram normalizadas e estão em função da relação vazios/cimento (η/Civ). Paralelamente pretendeu-se verificar qual o efeito do tipo de cura (sob tensão ou atmosférica) em misturas cimentadas com a realização de ensaios para tensões efetivas médias desde 250 kPa até 4000 kPa. Além disso, avaliou-se a variação do η/Civ e do tempo de cura para amostras curadas sob tensão. Os resultados mostram que, de um modo geral, com o aumento da tensão efetiva média, o tipo de cura não afeta os valores das tensões de desvio máximas. A parcela friccional tem uma predominância no comportamento tensão-deformação. O tipo de cura tem influência na definição da superfície de plastificação e da rigidez, verificando-se o aumento destas propriedades para amostras curadas sob tensão em relação a amostras curadas sob pressão atmosférica. Com base nos resultados obtidos nesta pesquisa, um modelo elasto-plástico com degradação da rigidez, que tem como parâmetros a resistência a compressão simples (qu), ângulo de atrito (ϕ’) e uma deformação equivalente (εs 0,7), foi proposto para simular o comportamento tensão-deformação de misturas de areias artificialmente cimentados em ensaios triaxiais, apresentando resultados satisfatórios. / The search for new technical solutions to reduce construction time of engineering works and to make them more cost-effective has been object of the research lines of the group of Geotechnical Engineering of Federal University do Rio Grande do Sul. Numerous studies have been conducted to analyse and understand the behaviour of artificially cemented. Portland cement is widely used for improving strength and deformability characteristics of soils. To study the contribution of cementation under high pressures, a 10 MPa confining pressure triaxial apparatus was built to study the stress-strain-dilatancy behaviour of artificially cemented soils cured under stress. In parallel a study was conducted on a artificially cemented uniform sand at three curing times (3, 7 and 28 days) to determine the unconfined compressive strength (qu) and splitting tensile strength (qt) according to voids/cement ratio (η/Civ) dosage methodology. The results showed that strength increases with the reduction of voids/cement ratio (η/Civ) and with the increasing of cure time (t). The tensile/compression ratio (qt/qu) is independent of curing time and presents a mean value of 0.15. In addition to these results, other granular soils mixtures with distinct types of cement and different curing times were analysed. A unique normalized curve was fit to unconfined compressive strength (qu) and splitting tensile strength (qt) against voids/cement ratio (η/Civ). At the same time, the effect of the curing type (under stress or atmospheric) was verified through triaxial compression tests with mean effective stresses ranging from 250 kPa to 4000 kPa. In addition, the variation of η/Civ and cure time was evaluated for samples cured under stress. The results show that, in general, by increasing the mean effective stress, the type of cure does not affect the values of the maximum deviatoric stress. The frictional portion is predominant in the stress-strain behavior. The type of cure affects the yielding surface and the stiffness of the samples. It was observed the increase in this properties for samples cured under stress compared to samples cured with atmospheric stress. Based on the outcomes of this study, with satisfactory results, an elastoplastic model with stiffness degradation (using unconfined compressive strength (qu), friction angle (’) and an equivalent strain (  s0.7)) was proposed to simulate the stress-strain behaviour of artificially cemented sands in triaxial tests.