A busca por novos materiais estruturais visa a melhoria da qualidade e desempenho das estruturas, impulsionando o desenvolvimento científico e tecnológico. O concreto auto-adensável surgiu da necessidade de se dispensar o difícil e oneroso trabalho de vibração do concreto, sendo definido como um material capaz de fluir dentro de uma fôrma, passando pelas armaduras e preenchendo a mesma, sem o uso de equipamentos de vibração. Esta pesquisa caracteriza-se como um estudo teórico-experimental da aderência aço-concreto, utilizando concreto do tipo auto-adensável, mediante ensaios monotônicos de flexão em vigas e de arrancamento seguindo o modelo padrão do Rilem-Ceb-Fip (1973). O estudo considerou como parâmetros fundamentais o tipo de concreto (auto-adensável e convencional), a resistência à compressão do concreto e os diâmetros das barras. Ainda, realizou-se um estudo com relação à variabilidade do concreto auto-adensável nos estados fresco e endurecido, constatando que este possui pequena variação. De posse dos resultados, buscou-se verificar a previsão das formulações empregadas na literatura e pelos principais códigos internacionais. De acordo com os resultados, o comportamento dos modelos de viga e de arrancamento para ambos os concretos foi similar, mostrando que o concreto auto-adensável possui características semelhantes ao concreto convencional, com as vantagens da trabalhabilidade no estado fresco. Quanto à análise numérica, os modelos desenvolvidos representaram de forma satisfatória o comportamento dos ensaios, e forneceram uma idéia do comportamento da tensão de aderência na sua interface. Com relação às formulações teóricas, verificou-se que tanto para o concreto convencional quanto para o auto-adensável, ocorre uma superestimativa da resistência de aderência. / The search for new structural materials aims the improvement of the structures performance, pushing the scientific and technological development. Self-compacting concrete (SCC) origin was due to the need to avoid the difficult and expensive process of concrete vibration. It has been defined as a material capable to flow inside a formwork, passing through the reinforcement and filling it completely, without using of any special equipment. This research is characterized as a theoretical and experimental study of steel-concrete bond, using SCC, through pull-out tests and beam tests standardized by Rilem-Ceb-Fip model. The study considered as main parameters the concrete type (ordinary concrete and SCC), its compressive strength and the steel bars diameters. Yet, a study of the variability of the properties of SCC, both in fresh and hardened state was also performed, showing that SCC is a very reliable material. The obtained results were compared with the ones established by the related bibliography and by the main international codes. According to the results, the behavior of the beams and pull-out tests were very similar for both concretes (SCC and OC), with the well know advantages for the SCC in fresh state. About the numerical approach, the developed models represented satisfactory the test behavior (beam and pull-out) and gave an idea of the bond stress behavior on the steel-concrete interface. About the theoretical formulations, it was verified the they usually overestimate the bond strength, for both types of concrete.

Made available in DSpace on 2014-07-29T15:03:36Z (GMT). No. of bitstreams: 1 pretext.pdf: 126548 bytes, checksum: 75b886ac104c5eb27a1e4f83ca04924f (MD5) Previous issue date: 2008-10-28 / The reinforced concrete structures are subject to interference from many factors that affect its stability and its performance and may generate the need for interventions and eventual reinforcement. There are several techniques of enhancing that can be employed and in the case of columns, the increase of the section with reinforced concrete is quite usual. This type of enhancement requires the attendance requirements to ensure its effectiveness, among which stand out in importance: meeting the needs and characteristics of project, the appropriate sizing, and the adhesion between concrete of different ages. Although the reinforcement of structures involve risk situations, and in many cases, are costly and uncertain, does not exist in the country a specific normalization for their specific design and implementation, thus they have been executed considering the normative disposals for project and execution of structures of armed concrete and in personal experiences. This research was evaluated the behavior of reinforced concrete columns required to flexural compression, with an initial section of 120 mm x 250 mm and height of 2000 mm in the compressed section and enhanced with a layer of 35 mm of self compact concrete and anchors. Was varied the amount of anchors and kept the other variables such as the concrete strength of the original columns and the enhanced columns, the initial rate of reinforcement, the eccentricity of the load test, the thickness of the reinforcement and the preparation of the substratum method. The strengthened columns had presented increasing load by increasing the amount of anchors used in the interface between the concrete of different ages. The improvement in the performance of the interface was observed, slowing the sputting and in one case, the column with a larger amount of anchors, with the crushing of concrete and sputting, almost simultaneously. There was a reduction of displacements caused by the decrease in ductility. These evidences indicate that the adopted technique of reinforcement if showed efficient, promoting consolidation of the composed section better / As estruturas de concreto armado estão sujeitas à interferência de diversos fatores que alteram sua estabilidade e seu desempenho podendo gerar a necessidade de intervenções e eventualmente reforço. Diversas são as técnicas de reforço que podem ser empregadas e, no caso dos pilares, o aumento da seção com concreto armado é bastante usual. Esse tipo de reforço exige o atendimento a requisitos que garantam a sua eficácia, dentre os quais se destacam em importância: o atendimento às necessidades e características de projeto; o adequado dimensionamento; e a aderência entre concretos de diferentes idades. Apesar de o reforço de estruturas envolver situações de risco e, em muitos casos, ser oneroso e incerto, não existe no país uma normalização específica para seu projeto e execução; assim têm sido executados considerando as disposições normativas para projeto e execução de estruturas de concreto armado e em experiências pessoais. Nesta pesquisa foi avaliado o comportamento de pilares de concreto armado solicitados à flexo-compressão reta, com uma seção inicial de 120 mm x 250 mm e altura de 2000 mm e reforçados na região comprimida com uma camada de 35 mm de concreto auto-adensável e chumbadores. Foi variada a quantidade de chumbadores e mantidas as demais variáveis como: as resistências dos concretos dos pilares originais e do reforço, a taxa de armadura inicial, a excentricidade de ensaio do carregamento, a espessura da camada de reforço e o método de preparação do substrato. Os pilares reforçados apresentaram ganhos crescentes de carga com o aumento da quantidade de chumbadores utilizada na interface entre os concretos de diferentes idades. Foi observada melhora no desempenho da interface, retardando o desplacamento e em um dos casos, no pilar com maior quantidade de chumbadores, ocorrendo o desplacamento e esmagamento do concreto quase simultaneamente. Houve redução dos deslocamentos horizontais dos pilares, provocada pela diminuição da ductilidade. Estas evidências indicam que a técnica de reforço adotada se mostrou eficiente, promovendo melhor consolidação da seção composta

Made available in DSpace on 2014-07-29T15:03:39Z (GMT). No. of bitstreams: 1 dissertacao poliana paula nascimento.pdf: 3745799 bytes, checksum: 3d668e197266750a56c400714f13762a (MD5) Previous issue date: 2009-09-11 / Many problems involving cases of ruins of buildings, bridges, etc., specifically ruin of columns, which are among the most important links in the whole structure, due to project flaw, bad execution or even for the evolution and changing habits. Therefore it has been of fundamental importance researches on the experimental behavior of structures. When conducting a strengthening column using dry with increased self-compacting concrete, it has the drawback of a sudden rupture by peeling the reinforcement. For this, there is a need to study the area of adhesion between substrate and to strengthen and create a way of preparation of this interface area so that the column increases may come into ruin in a ductile flexural as well as in a monolithic column. Thus, it s been developed an experimental study in the School of Civil Engineering, Federal University of Goias, based on analysis of the breaking loads, lateral displacements and deformations of the column of materials for different ways of preparing the surface of the column to be strengthened. The experimental phase of this work was based on testing of nine reinforced concrete columns, which are tested under flexural compression, with eccentricity of 60 mm. Two columns were used as reference columns, one with the original dimensions of the column and the other monolithic concreted in the thickness of a sin reinforced the others received a layer of 35 mm thick concrete selfcompacting in the compressed face. For preparation of the interchange between the two materials, it was proceeded with the scarification and the realization of grooves along this surface, where inserted connectors attached to transverse reinforcement of the columns, varying the position and quantity of the same. It can be concluded that not only quantity, but mainly the location of connectors used in the connection between the substrate and reinforcement, is essential for a good result of resistance and rupture mode. Must be observed a minimum spacing between the connectors strengthening to ensure a more monolithic unit, enabling a ductile rupture occurred as the reference column / Muitos são os problemas envolvendo casos de ruína de edifícios, pontes etc, especificamente ruína de pilares, que são uns dos elos mais importantes do conjunto estrutural, por falha de projeto, de execução ou ainda, pela evolução e alteração de hábitos. Por isso tem sido de fundamental importância as pesquisas que abordam o comportamento experimental das estruturas. Ao se realizar um reforço de pilar utilizando-se aumento de seção com concreto auto-adensável, tem-se o inconveniente de uma ruptura brusca por desplacamento do reforço. Para tanto, verifica-se a necessidade de estudar a zona de aderência entre substrato e reforço e criar um modo de preparo desta zona de interface de modo que o pilar reforçado possa entrar em ruína de forma dúctil por flexão, assim como acontece em um pilar monolítico. Assim, desenvolveu-se um estudo experimental na Escola de Engenharia Civil da Universidade Federal de Goiás, baseado na análise de cargas de ruptura, deslocamentos laterais dos pilares e deformações dos materiais para diferentes formas de preparo da superfície do pilar a ser reforçado.A etapa experimental deste trabalho baseou-se no ensaio de nove pilares de concreto armado, sendo estes ensaiados à flexo-compressão reta, com excentricidade de 60 mm. Dois pilares foram usados como pilares de referência, sendo um com as dimensões originais do pilar e o outro monolítico concretado na espessura de um peça reforçada, os demais receberam uma camada de 35 mm de espessura de concreto auto-adensável na face comprimida. Para preparo da zona de interface entre os dois materiais, procedeu-se com a escarificação e a realização de sulcos ao longo desta superfície, onde foram inseridos conectores ligados a armadura transversal do pilar, variando-se a posição e a quantidade dos mesmos. Pode-se concluir que não só a quantidade, mas principalmente, a localização dos conectores utilizados na ligação entre substrato e reforço, são imprescindíveis para um bom resultado de resistência e modo de ruptura. Sendo necessário respeitar um espaçamento mínimo entre os conectores do reforço para se garantir um trabalho mais monolítico da peça, possibilitando uma ruptura dúctil como a ocorrida nos pilares de referência

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-09-30T15:03:49Z No. of bitstreams: 1 Dissertação - Luciano Moreira de Sousa Neto.pdf: 29845322 bytes, checksum: d7781fb07ffa9fee00b00aa4bd8a416f (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-09-30T18:57:55Z (GMT) No. of bitstreams: 1 Dissertação - Luciano Moreira de Sousa Neto.pdf: 29845322 bytes, checksum: d7781fb07ffa9fee00b00aa4bd8a416f (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-09-30T19:01:17Z (GMT) No. of bitstreams: 1 Dissertação - Luciano Moreira de Sousa Neto.pdf: 29845322 bytes, checksum: d7781fb07ffa9fee00b00aa4bd8a416f (MD5) / Made available in DSpace on 2015-09-30T19:01:17Z (GMT). No. of bitstreams: 1 Dissertação - Luciano Moreira de Sousa Neto.pdf: 29845322 bytes, checksum: d7781fb07ffa9fee00b00aa4bd8a416f (MD5) Previous issue date: 2014-03-21 / Não Informada / High performance concrete, in addition to high strength, has lower permeability and higher durability. The self-compacting concrete reduces the need for densification and scattering and facilitates concreting of slender pieces. The combination of these two concrete on one allows the linking of the qualities of both. In the construction industry, concrete production has potential to reuse some kinds of residues. In this work, the residue of industrial glass was used as mineral additive in the combined production of high performance concrete and self-compacting concrete. The residue of industrial glass, after the grinding process, was added to the concrete with the aim to evaluate its properties in fresh and hardened state. It was possible to evaluate and compare the performance of industrial waste glass with silica fume. Following the experimental program, the materials were characterized and Marsh Funnel tests and minicone of Kantro were performed with the superplasticizer MC-PowerFlow 1102. The optimum dosage of superplasticizer was evaluated in fresh concrete tests. Concrete were produced and characterized in fresh and hardened states. For characterization of concrete in the fresh state, the following tests were used: slump flow, T500, L box, funnel method V and segregation column method. For characterization of concrete in the hardened state, the following tests were performed: axial compression tests, traction by diametrical compression, static modulus of elasticity and water absorption by immersion. Concrete with the addition of waste ground glass hit resistance close to 67 MPa at 90 days, while the concrete with addition of silica fume hit resistance close to 88 MPa at the same age. As the concrete produced with addition of industrial waste glass obtained swift technical skills of high performance concrete and selfcompacting concrete, the results of this research were considered satisfactory. / O concreto de alto desempenho, além de alta resistência, tem baixa permeabilidade e maior durabilidade. O concreto autoadensável reduz a necessidade de adensamento e espalhamento e facilita a concretagem de peças esbeltas. A combinação desses dois concretos em um só permite a junção das qualidades de ambos. Na indústria da construção civil, a produção de concreto é um celeiro potencial para reutilizar alguns tipos de resíduos. Neste trabalho, o resíduo de vidro industrial foi usado como aditivo mineral na produção combinada de concreto de alto desempenho e autoadensável. O resíduo de vidro industrial, após o processo de moagem, foi adicionado ao concreto, com o objetivo de avaliar as suas propriedades no estado fresco e endurecido. Foi possível avaliar e comparar o desempenho do resíduo de vidro industrial com a sílica ativa. Seguindo o programa experimental, os materiais foram caracterizados e ensaios de funil de Marsh e minicone de Kantro foram realizados com o superplastificante MC-PowerFlow 1102. A dosagem ótima do superplastificante foi avaliada em ensaios de concreto fresco. Os concretos foram produzidos e caracterizados nos estados fresco e endurecido. Para a caracterização do concreto no estado fresco, foram realizados os seguintes ensaios: slump flow, T500, caixa L, método de funil V e método da coluna de segregação. Para a caracterização do concreto no estado endurecido, foram realizados os seguintes ensaios: ensaio de compressão axial, tração por compressão diametral, determinação do módulo de compressão estático de elasticidade e determinação de absorção de água por imersão. O concreto com a adição de resíduo de vidro moído atingiu resistência próxima de 67 MPa aos 90 dias, enquanto o concreto com a adição de sílica ativa atingiu resistência próxima de 88 MPa na mesma idade. Como o concreto produzido com adição de resíduos de vidro industrial obteve qualidades técnicas de concreto de alto desempenho e de concreto autoadensável, os resultados desta pesquisa foram considerados satisfatórios.

Le béton auto-plaçant renforcé de fibres (BAPF) est l’un des récents développements dans le monde de la technologie du béton combinant les performances de l’auto-consolidation avec la ductilité post-pic et les nombreux avantages face à la fissuration grâce à la présence des fibres dans le béton. L’utilisation de BAPF accroît l’efficacité économique globale de la phase de construction en réduisant la main d’oeuvre, ou la consommation d’énergie requise, en accélérant la vitesse de construction, la réduction ou l’élimination de ferraillage conventionnel et à la simplification des détails et placement du ferraillage. Le BAPF a gagné en popularité dans ses utilisations durant les dernières années telles dans les tabliers de ponts, les poutrelles et les poutres. En dépit de preuve d’amélioration de synergie entre la technologie d’auto-placement et l’ajout de fibres dans le BAPF, il est obligatoire de déterminer les propriétés convenables de ce matériau pour trouver les caractéristiques inappropriées dans le béton à l’état frais et durci. A cet égard, les défauts, tels l’agglomération de fibres, la ségrégation et la performance d’écoulement et le placement incorrects à cause de propriétés rhéologiques inappropriées à l’état frais, entraînent une réduction dans la résistance évaluée. L’objectif principal de cette étude est d’évaluer les propriétés du béton auto-plaçant (BAP), des mélanges intégrant différentes teneurs en granulats et du BAPF (avec insertion de différents types et teneurs de fibres). Ceci peut aider au développement de BAPF avec une rhéologie adaptée et une performance mécanique adéquate incluant une résistance d’adhésion et de cisaillement convenable pour des applications structurelles. Dans le but d’évaluer l’effet des fibres sur les propriétés rhéologiques de BAP à l’état frais, des mélanges intégrant quatre types de fibres avec différents élancement (L/D) seront étudiés. Ces fibres incluent des crochets d’acier (STH 55/30), du fil d’acier tréfilé (STN 65/13), de la macro-fibre synthétique de propylène (PP 56/38) et de l’alcool polyvinylique (PVA 60/12) avec différentes teneurs volumiques (0.25%, 0.5%) ajoutées au BPA de référence. Tous les mélanges ont un rapport w/b fixé à 0,42 et la teneur en granulats grossiers est respectivement de 29, 32 et 35% par volume de béton. Les caractéristiques de béton frais ont été évaluées en considérant l’affaissement, l'évaluation du temps d’écoulement (V-funnel), l'amplitude à l'écoulement du BAP (J-Ring), le tassement de surface et le rhéomètre ConTec. Les propriétés du béton durci, en particulier la résistance à la compression, la résistance à la traction par fendage, la résistance à la flexion, et le module élastique ont été évaluées. L’effet des types de fibres, des teneurs en fibres et en granulats sur la résistance à la rupture et la robustesse du BAP au cisaillement des mélanges optimisés, incluant le BAP de référence, le SCCAGG (32% and 35%), le FRSCC ST-H (0.25% and 0.5%), le FRSCCPP (0.25% and 0.5%), le PVA (0.25% and 0.5%) et le ST-N (0.25% and 0.5%) ont été testés en utilisant l’essai de cisaillement direct pour évaluer la résistance en cisaillement et la résistance résiduelle du béton. Les résultats des essais prennent en considération la capacité portante en cisaillement de l’élément structurel fabriqué à partir de BAPF. Les résultats des essais montrent que l’ajout de fibres était beaucoup plus efficace que l’accroissement de la teneur en agrégats sur la résistance au cisaillement du BAP. L’amélioration de la contrainte au cisaillement à la rupture comparée au mélange de référence est plus grande avec 16.3% pour l’ajout de fibre de type STN 0.5%, 15.8% pour l’ajout de fibre de type STH 0.5%, 14.92% pour l’ajout de fibre de type PP 0.5% et 7.73% pour l’ajout de fibre de type PVA 0.5%. De plus, l’ajout de fibres améliore le comportement post-pic en cisaillement du BPA en comparaison à l’augmentation de la teneur en granulats. L’augmentation de la teneur en fibres de 0.25% à 0.5%, par volume de béton, a amélioré la résistance et la ténacité au cisaillement, le comportement en flexion peu importe le type de fibres. Cette amélioration a été la plus élevée dans le cas du STH 0.5% et la plus basse pour des valeurs de PVA0.5%. La réponse de la résistance à l’adhésion des barres d’armatures localisées à différentes hauteurs de l’élément de mur (effet top-bar) a été étudiée pour des mélanges optimisés; le BPA de référence, les mélanges ST-H 0.5, et PP 0.5 ont été testés à travers l’essai d’arrachement direct des barres coulées dans le large élément de mur. Utilisation de fibres de propylène et de fibres à crochets d’acier au BPA a légèrement augmenté le facteur de modification à l’adhérence (effet top-bar) de 1 dans le cas du BPA jusque 1,1 et 1,2 pour les fibres de propylène et de crochets d’acier respectivement. Les éléments de mur fabriqués à partir du mélange de BPA de référence a montré la distribution de résistance la plus uniforme avec moins de 5% de réduction de sa résistance à l’adhérence sur la hauteur. Ces pertes de résistance à l’adhérence pour les éléments de mur coulés avec du BPA intégrant les de fibres de propylène et de fibres à crochets d’acier sont respectivement de 10% et 20%. / Abstract : Fiber reinforced self-consolidating concrete (FR-SCC) is one of the recent developments in the world of concrete technology which combines the self-consolidating performance with the post-peak ductility and multiple cracking advantages due to presence of fiber reinforcement in concrete. The use of FR-SCC increases the overall economic efficiency of the construction process by reducing the workforce, or energy consumption required, increasing speed of construction, reduction or elimination of the conventional reinforcement and to the simplification of reinforcement detailing and placement. The FR-SCC has gained increasing popularity applications in the last few years such as bridge decks, girders and beams. Despite the improvement evidence of synergy between self-consolidating technology and fiber addition in the FR-SCC, finding adequate properties of this material is mandatory to find any improper characteristics in the fresh and hardened states. In this regards, defects, such as fiber clustering, segregation and improper flow performance and placement due to improper rheological properties in the fresh state, which leads to reduction in strength, are evaluated. The main objective of this study is to evaluate some rheological and mechanical properties of self-consolidating concrete (SCC) mixtures with different aggregate contents and FR-SCC (incorporating different fiber types and contents). This can help to develop of FR-SCC with adapted rheology and proper mechanical performance including bond strength and shear strength for structural application. In order to evaluate the effect of fibers on rheological properties of SCC in the fresh state, mixtures incorporating four types of fibers with different aspect ratio (L/D) were investigated. The fibers included steel hooked (STH 55/30), steel drawn wire needles (STN 65/13), synthetic macro-fiber propylene (PP 56/38) and polyvinyl alcohol (PVA 60/12) with variety of volume content (0.25%, 0.5%) added to the SCC reference. All mixtures has a fixed w/b ratio of 0.42 and different coarse aggregate contents of 29, 32 and 35%, by volume of concrete. The fresh concrete characteristics were evaluated by considering the slump flow, V-funnel, J-Ring, surface settlement and ConTec rheometer. The hardened properties, mainly compressive strength, splitting tensile strength, flexural strength, flexural toughness, and modulus of elasticity were evaluated. The effect of fiber type, fiber content, and coarse aggregate content on ultimate shear load and shear toughness of the optimized mixtures. The mixtures including SCC reference, SCC with aggregate volume of 32% and 35% (SCCAGG 32% and SCCAGG 35%), SCC incorporating ST-H fibers with the dosages of 0.25% and 0.5% (FRSCC ST-H 0.25% and FRSCC ST-H 0.5%), SCC incorporating PP fibers with the dosages of 0.25% and 0.5% (FRSCC PP 0.25% and FRSCC PP 0.5%), SCC incorporating PVA fibers with the dosages of 0.25% and 0.5% (FRSCC PVA 0.25% and FRSCC PVA 0.5%) and SCC incorporating ST-N fibers with the dosages of 0.25% and 0.5% (FRSCC ST-N 0.25% and FRSCC ST-N 0.5%) were tested using the direct shear push-off test to evaluate shear strength and residual shear strength of the concrete. These test results could be used in the shear load carrying capacity of the structural element made by FRSCC. The test results show that adding fiber was much more effective than increasing aggregate content on the shear strength behaviour of SCC. The ultimate shear stress improvement of the mixtures incorporating fiber compared to the SCC reference mixture were 16.3% for STN 0.5%, 15.8% for STH 0.5%, 14.92% for PP 0.5%, and 7.73% for PVA 0.5% mixture. Moreover, adding fibers improved the post-peak shear behaviour of SCC compared to addition of aggregate content. Increasing the fiber content from 0.25% to 0.5%, by volume of concrete, improved shear strength, shear toughness and flexural toughness behaviour regardless of the fiber types. This enhancement was highest in the case of STH 0.5% and lowest values for PVA0.5%. The bond strength response of rebars located at different heights of the wall element (top-bar effect) investigated for optimized mixtures, including SCC reference, ST-H 0.5, and PP 0.5 mixtures was tested through direct pull-out test of rebars cast in the large wall elements. Adding propylene and steel hooked fibers to SCC is found to slightly increase the bond modification factor (top-bar effect) from 1 in the case of SCC up to 1.1 and 1.2 for propylene and steel hooked fibers, respectively. The wall elements made with SCC reference mixture showed the most uniform bond strength distribution and had less than 5% reduction of bond strength along the height. These bond strength losses for wall element cast with SCC incorporating 0.5 % of steel hooked fiber and that of propylen fiber with the same volume are 10% and 20%, respectively.

Evolution of concrete is continuously taking place to meet the ever-growing demands of the construction industry. Self compacting concrete (SCC) has emerged as a result of this demand to overcome the scarcity of labour. SCC is widely replacing normal vibrated concrete (NVC) these days owing to its advantages such as homogeneity of the mix, filling ability even in heavily congested reinforcement, smooth finish, reduction in construction time etc. The ingredients used for SCC is the same as that of the NVC. But the proportioning of ingredients to achieve self compactability alters the microstructure of SCC which in turn affects the mechanical and fracture properties. Moreover, the mineral admixtures such as fly ash and silica fume when used for improving the workability of SCC help in the development of the microstructural skeleton. In this study, three SCC mixes SCC1- made with only cement, SCC2 - with fly ash in addition to cement and SCC3 - with fly ash and silica fume in addition to cement for achieving normal, medium and high strength SCC respectively are cast. The microstructural changes in SCC with and without mineral admixtures over a period of time are studied using different techniques such as scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The modification of mechanical properties at microstructural level brings difference in the behavior at macro level. Hence in this study, the mechanical properties at microstructural are obtained by using microindentation test and are scaled up to the macro level to predict the influence of micromechanical properties on macro response. The fracture properties of SCC is considered to be the interest of this study and is carried out with the help of advanced techniques such as acoustic emission (AE) and digital image correlation (DIC). From the various studies carried out, it is inferred that the mixes with mineral admixtures behave in a more brittle manner when compared to mix having no mineral admixture. It is also observed that class ‘F’ fly ash hydrates at a slow pace and the strength gain is observed after 28 days and even beyond 90 days. Hence, it is concluded that it is appropriate to consider the strength at 90 days instead of 28 days for a SCC mix with class ‘F’ fly ash. Silica fume on the other hand is observed to result in a more rapid gain in strength and this can partially offset the delay in strength gain due to fly ash.

This diploma thesis examines the properties of concrete with reinforcement, designed for the production of a concrete egg-shaped tubes . The stress is put on using various types of fiber reinforcements. Theoretical part is divided into 4 subsections. The topic of the first subsection is a concrete in general. Second subsection deals with various technology of production of concrete pipes. The third subsection is focused on description and summary of basic properties of concrete and reinforced concrete tubes. The last subsection deals with standardized procedures for testing concrete. Experimental part of this thesis is divided into two subsection. First subsection deals with design of a reference sample. Six different samples of a concrete were designed and their rheological properties were tested. Second subsection deals with the additi-on of various types of fiber reinforcement to the reference sample. Eight different admixtures of a concrete were added to the reference sample. Properties of these admixtures were tested in fresh and hardened state.

Självkompakterande betong (SKB) eller som den också kallas vibreringsfri betong upptäcktes och utvecklades i Japan i slutet av 1980- talet. Anledningen till detta utvecklingsarbete var att betong gjutning väldigt kämpigt och tillgången på erfarna betongarbetare började bli låg. I Sverige använde man självkompakterande betong året 1993 som tekniken hämtades hem av CBI Betonginstitutet. Användning av självkompakterande betong leder till många fördelar som skiljer sig från den vanliga betongen avseende arbetsmiljö t.ex. slipper man vibrering och undviker tungt arbete som i konsekvens minskar antal skador på arbetsplatsen. Utöver detta ger SKB förkortad arbetstid, bättre utförande och möjlighet till arbetskraftbesparing. Sedan 1997 har Sverige ökat användning av SKB i platsgjutning medan andra länder som Danmark har gått fram till ca 30 % av sin platsgjutning. Den låga användningen beror på att självkompakterande betong är väldigt känslig och dyrare eftersom den innehåller mer tillsatsmaterial. Huvuddelen av projektet bestod av att ställa frågor till experter i byggbranschen om självkompakterande betong för att få största möjliga mängd av informationer. Informationer som vi har fått var emellan åtta besök och sex mail. Syftet med examensarbete är att öka kunskap om orsaken till låg utveckling av SKB på platsgjutning och kunskap om arbetsmiljö. Vidare syftar arbetet till att lyfta fram de arbetsmiljömässiga och konstruktiva fördelarna samt sprida information om dessa. Informationerna visar att anledningen till den låga användningen av SKB framför allt är priset.  Men tidigare misslyckanden och varierande betongegenskaper är också en av anledningarna. Genom att öka användning av SKB där man många fördelar bland annat ekonomisk vinst på lång sikt och framför allt bättre arbetsmiljö med tanke på samhället. / Self-compacting concrete (SCC) or vibrated concrete was invented and developed in Japan in the late 1980's. Working with concrete is very hard and all of that is because of injuries that come from using of the usual concrete.  In Sweden, they used self-compacting concrete since 1993 when the technology has brought to Sweden from Japan by the Swedish cement and concrete Research institute. Self-compacting concrete has many advantages that are different from the traditional concrete according to the work environment which include avoidance of vibration and heavy work and all these can reduce the number of injuries at workplace. Shortened construction time and possibilities to save manpower are additional benefits. Today, self-compacting concrete is used for about 10 % on site casting in Sweden. Many other countries have gone forward in using of SCC, Denmark uses about 30%. The low use is due to the sensitivity of SCC and expensive because it contains more filler. The main work of the project consists of the interviews with the related persons in the building branch and questions to them about self-compacting concrete to get the maximum amount of information. Information that we have received was between eight visits and six mail. The aim of the thesis is to increase knowledge about the cause of the low development of SCC in place casting and knowledge of the work environment. Furthermore, this work aims to highlight the work environment and constructive advantages and disseminate information about them. The study shows that the reason for the low use of SCC is especially the price. But the previous failures and varying concrete properties are also such of these reasons. Increasing the use of SCC leads to many benefits including economic profit in the long term, and especially from the society side.

The diploma thesis follows up on the bachelor thesis and deals with the issue of light-transmitting concrete LTC. The aim of thesis determines the transparency and its decrease due to durability. The terotical part deals with extension of LTC issues and follows up reserch from bachelor thesis. The teory is also focused on the issue of glass optical fibers. The experimental part deals with the influence of selected durability test on transparency of LTC. Transparency is determined by mesuring devise called black box. In the conclusion is summarized influences witch affects transparency and evaluation of whether the selected fibers are suitable for outdoor use.

In the development of concrete structures and its finishes we are constantly looking for new ways to highlight the aesthetic value of the concrete. With all the possibilities of shapes, textures and colours, an architectural concrete in the hands of an architect and designer becomes a material, which can be used to express different individual and specific ideas. It is necessary to recognize and cope with these possibilities, but also the limits, which determine the properties of concrete as the proper design and implementation creates excellent finishes that are otherwise inaccessible to other materials and technologies. The theoretical part includes an extensive summary carries out a research on issues of architectural concrete and its production. From this research comes a new definition of architectural concrete and the newly redesigned and determined classes of architectural concrete with respect to the continuous development of technologies and production possibilities, rendering and surfacing. The aim of the thesis is to verify the possibilities of producing quality architectural concrete and additional treatment of the surface with respect to the desired aesthetic quality.