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Betony na bázi tuhých zbytků z fluidního spalování / Concretes based on solid residues from fluidized bed combustionDarakevová, Michaela January 2015 (has links)
The work is focused on the possible use of secondary raw materials of the energy industry in the construction industry, particularly in concrete applications, where as the main raw material of the binder composition are used solid fluidized bed combustion residues - filter and ground. The aim of this work is to prepare concrete or concretes based on solid residues from fluidized bed combustion, that will fulfill or at least approximately approach by their parameters to commonly used concretes based on portland cement. The experimental part is divided into several chapters, at first the results of analyzes of feedstock and solid residues from fluidized bed combustion, portland cement and calcium hydroxide. Other chapters describe proposals for alternative binders, concrete, characterization and testing. Mainly were observed changing properties of the prepared concretes by changing the ratio of binders and aggregates. In tests were evaluated mainly mechanical properties and phase composition.
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Concrete surface resistivity profiles along the splash zone on bridge piles exposed to sea waterUnknown Date (has links)
Prevention of the corrosion of steel reinforcement embedded in concrete is a constant challenge in engineering. A study of concrete surface resistivity versus elevation of partially immersed reinforced concrete structures in a marine splash zone has been developed and correlations made between concrete quality and chloride diffusion, i.e., aggressive ion permeability. A conditioning procedure was developed in which the concrete moisture content is increased by direct contact with fresh water for several days. The electrical resistivity of concrete is known to be primarily a function of the degree of water saturation. Correlations between field obtained concrete surface resistivity values versus chloride diffusivity, and between normalized resistivity measured on cores obtained from the field versus chloride diffusivity has been established. The resistivity values were measured on structures with different concrete mixes and various ages. / by Andres M. Suarez-Solano. / Thesis (M.S.C.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
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Concrete diffusivity and its correlation with chloride deposition rate on concrete exposed to marine environmentsUnknown Date (has links)
The aim of this study was to investigate the diffusion of chloride ions into concrete samples that were exposed in scenarios that simulate the splash, tidal, atmospheric, and immersed portions of a marine structure. To study the atmospheric deposition, the project also investigated the relationship between chloride ion deposition on the wet candle and its accumulation into concrete samples. Results from the wet candle experiment indicated that between 2% and 45% of the chlorides deposited per square meter of exposed area could be found within the concrete samples. After 6 months, slag G1a blocks showed the most resistance to chloride penetration in the tidal and splash simulations. After 10 months of exposure, fly ash samples had the slowest rates of diffusion in the tidal simulation while the fly ash + silica fume samples and the slag samples measured similar rates of diffusion within the tidal zone. After 90 days of curing, cylinders composed of 20% fly ash & 8% silica fume measured the highest average resistivity values and were found to be less vulnerable to chloride ion penetration than the 20% fly ash and the 50% slag concrete through rapid migration tests. / by Victor Anthony Echevarria. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
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Execução de blocos para alvenaria estrutural utilizando concreto fluido / Implementation of blocks for structural masonry using fluid concretePinto, Bruno Henrique 05 June 2018 (has links)
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Previous issue date: 2018-06-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As complicações ocasionadas pelas irregularidades presentes na face de assentamento dos blocos de alvenaria estrutural, provenientes de procedimentos correntes de fabricação, possibilita um campo de estudo para otimização na melhoria dessas irregularidades. Para tanto, este trabalho tem por finalidade propor uma alternativa de fabricação dos blocos de alvenaria estrutural através do uso e aplicação de concreto fluido com os traços 1:3, 1:5 e 1:7, cujas resistências à compressão deles e dos prismas, atendam às exigências das normas NBR 15961-1 e NBR 15961-2. Assim, além de moldados e confeccionados os blocos e os prismas, neste trabalho são apresentados ensaios de ambos, bem como os ensaios das argamassas de assentamento mista e polimérica. Em alguns destes ensaios utilizaram-se LVDTs e Strain-Gages, com objetivo de verificar os seus deslocamentos e suas deformações, e consequentemente as tensões atuantes, nos blocos e nos prismas. / Complications arising from imperfections on the bonded surface of structural masonry blocks, from current manufacturing procedures, makes it a field of study for optimization in the improvement of these irregularities. To this end, this paper aims to propose an alternative to the manufacture of structural masonry block through the use and application of fluid concrete with mixture 1:3, 1:5 and 1:7, whose resistance to compression them and prisms, meet the requirements established by the Brazilian technical standards NBR 15961-1 and NBR 15961-2. Thus, this work describes tests performed on blocks and prisms. The prisms were tested with mixed and polymeric block-laying mortars. In some of these tests using LVDTs and Strain Gages to check their displacements and their deformations, and consequently tensions, in the blocks and prisms.
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Execução de blocos para alvenaria estrutural utilizando concreto fluido /Pinto, Bruno Henrique January 2018 (has links)
Orientador: Maria da Consolação Fonseca Albuquerque / Resumo: As complicações ocasionadas pelas irregularidades presentes na face de assentamento dos blocos de alvenaria estrutural, provenientes de procedimentos correntes de fabricação, possibilita um campo de estudo para otimização na melhoria dessas irregularidades. Para tanto, este trabalho tem por finalidade propor uma alternativa de fabricação dos blocos de alvenaria estrutural através do uso e aplicação de concreto fluido com os traços 1:3, 1:5 e 1:7, cujas resistências à compressão deles e dos prismas, atendam às exigências das normas NBR 15961-1 e NBR 15961-2. Assim, além de moldados e confeccionados os blocos e os prismas, neste trabalho são apresentados ensaios de ambos, bem como os ensaios das argamassas de assentamento mista e polimérica. Em alguns destes ensaios utilizaram-se LVDTs e Strain-Gages, com objetivo de verificar os seus deslocamentos e suas deformações, e consequentemente as tensões atuantes, nos blocos e nos prismas. / Abstract: Complications arising from imperfections on the bonded surface of structural masonry blocks, from current manufacturing procedures, makes it a field of study for optimization in the improvement of these irregularities. To this end, this paper aims to propose an alternative to the manufacture of structural masonry block through the use and application of fluid concrete with mixture 1:3, 1:5 and 1:7, whose resistance to compression them and prisms, meet the requirements established by the Brazilian technical standards NBR 15961-1 and NBR 15961-2. Thus, this work describes tests performed on blocks and prisms. The prisms were tested with mixed and polymeric block-laying mortars. In some of these tests using LVDTs and Strain Gages to check their displacements and their deformations, and consequently tensions, in the blocks and prisms. / Mestre
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Contribuições à produção do concreto fluido com fibras de borracha e de polipropileno e adição de resíduos do beneficiamento do mármore e granito / Contributions obteining of the self compacting concrete using residue of the marble and granite and study of mechanical propertiesSilva, Tássia Neuda de Moraes 07 November 2013 (has links)
The Fluid Concrete (FC) is a concrete that has high fluidity, which may allow the filling of molds without the need of mechanical compaction, only under the action of its own weight. As a concrete whole, the FC has low tensile strength, and an alternative to minimize this limitation is the inclusion of fibers to the concrete. The incorporation of fiber reinforced composite and induce tensile stresses. Within this context, this paper aims to provide a contribution to the production of a fluid concrete fiber, rubber and polypropylene and addition of waste from the processing of marble and granite(FFC). The methodology dosage used was Gomes (2002) for obtaining fluid concrete (FC) being adapted for insertion of fiber. To study the properties of compacting tests were carried out in the fresh state, such as scattering, V funnel and box L. To check the mechanical properties tests were performed in the hardened state, such as compression, tensile and modulus of elasticity with cylindrical body-of - proof dimensions of 10cm x 20cm RC and FFC, with fiber content rubber 2.0% polypropylene and 0.25% of the amount by weight of cement. As a result, the SC showed a decrease in scattering maximum diameter with increasing fiber content entered. The compressive strength and modulus of elasticity decreased, since the tensile strength showed an increase when compared to RC. From the results it is concluded that the FFC is not self compacting concrete, but has characteristics of self compacting, the increase in tensile strength indicates a higher ability to absorb impact. The FFC helps reduce scrap waste, reducing the environmental impact by becoming a ecoeffient concrete. / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Define-se como Concreto Fluido (CF) um concreto que apresenta abatimento entre 18cm e 25cm. Essa elevada fluidez pode permitir o preenchimento de fôrmas sem que haja necessidade de adensamento mecânico, apenas sob a ação do seu peso próprio. Como todo concreto, o CF possui baixa resistência à tração, e uma alternativa de minimizar essa limitação é a inserção de fibras ao concreto. A incorporação de fibras pode reforçar o compósito e permitir maior absorção de tensões de tração. Dentro deste contexto, o presente trabalho tem como objetivo proporcionar uma contribuição ao estudo de compósitos por meio da produção de um concreto fluido com fibras de borracha e de polipropileno e adição de resíduos do beneficiamento de mármore e granito (CFF). A Metodologia de dosagem utilizada para a obtenção desse concreto foi a de Gomes (2002) estabelecida para concreto autoadensável, com adaptações para inserção das fibras. Para o estudo das propriedades de adensabilidade foram realizados ensaios no estado fresco, tais como: espalhamento, funil V e caixa em L. Para verificação das propriedades mecânicas foram realizados ensaios no estado endurecido, tais como: compressão, tração e módulo de elasticidade, com corpos-de-prova cilíndricos de dimensões de 10cm x 20cm de CR e de CFF, com teor de fibras de borracha de 2,0% e de polipropileno de 0,25% da quantidade de cimento em massa. Como resultados, o CFF apresentou características de autoadensabilidade com um diâmetro máximo de espalhamento de 62,5cm. A resistência à compressão e o módulo de elasticidade apresentou uma redução, já a resistência à tração apresentou um aumento quando comparados ao Concreto de Referencia (CR). Dos resultados conclui-se que o CFF possui características de autoadensabilidade e acréscimo na resistência à tração. O CFF com fibras permitiu a incorporação de um resíduo inservível, reduzindo o impacto ambiental e se caracterizando como um concreto ecoefiente.
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