EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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Resultados da Pesquisa
Item Influence of cooling methods on the residual mechanical behavior of fire-exposed concrete : an experimental study.(2019) Carvalho, Espedito Felipe Teixeira de; Silva Neto, João Trajano da; Soares Junior, Paulo Roberto Ribeiro; Maciel, Priscila de Souza; Fransozo, Helder Luis; Bezerra, Augusto Cesar da Silva; Gouveia, Antônio Maria Claret deThis work reports the main conclusions of a study on the mechanical behavior of concrete under ISO 834 fire with different cooling methods. The aim of this research was to provide reliable data for the analysis of structures damaged by fire. The experimental program used cylindrical concrete test specimens subjected to ISO 834 heating in a furnace up to maximum gas temperatures of 400, 500, 600, 700, and 800 ◦C. The compressive strength was measured in three situations: (a) at the different temperature levels reached in the furnace; (b) after a natural cooling process; and (c) after aspersion with water at ambient temperature. The results indicate that the concrete residual compressive strength is fairly dependent on the maximum temperature reached in the furnace and revealed that concrete of a lower strength preserved relatively higher levels of strength. The cooling method significantly influenced the strength, albeit at a lower intensity. In all cases, the residual strength remained in the range of 38% to 67% of the strength at ambient temperature. The statistical analysis showed that the data obtained by the experimental program are significant and confirmed the influence of the conditions imposed on the residual strength.Item Influence of cooling methods on the residual mechanical behavior of fire-exposed concrete : an experimental study.(2019) Carvalho, Espedito Felipe Teixeira de; Silva Neto, João Trajano da; Soares Junior, Paulo Roberto Ribeiro; Maciel, Priscila de Souza; Fransozo, Hélder Luís; Bezerra, Augusto Cesar da Silva; Gouveia, Antônio Maria Claret deThis work reports the main conclusions of a study on the mechanical behavior of concrete under ISO 834 fire with different cooling methods. The aim of this research was to provide reliable data for the analysis of structures damaged by fire. The experimental program used cylindrical concrete test specimens subjected to ISO 834 heating in a furnace up to maximum gas temperatures of 400, 500, 600, 700, and 800 ◦C. The compressive strength was measured in three situations: (a) at the different temperature levels reached in the furnace; (b) after a natural cooling process; and (c) after aspersion with water at ambient temperature. The results indicate that the concrete residual compressive strength is fairly dependent on the maximum temperature reached in the furnace and revealed that concrete of a lower strength preserved relatively higher levels of strength. The cooling method significantly influenced the strength, albeit at a lower intensity. In all cases, the residual strength remained in the range of 38% to 67% of the strength at ambient temperature. The statistical analysis showed that the data obtained by the experimental program are significant and confirmed the influence of the conditions imposed on the residual strength.Item Influence of cooling methods on the residual mechanical behavior of fire-exposed concrete : an experimental study.(2019) Carvalho, Espedito Felipe Teixeira de; Silva Neto, João Trajano da; Soares Junior, Paulo Roberto Ribeiro; Maciel, Priscila de Souza; Fransozo, Hélder Luís; Bezerra, Augusto Cesar da Silva; Gouveia, Alberto Frederico Vieira de SousaThis work reports the main conclusions of a study on the mechanical behavior of concrete under ISO 834 fire with different cooling methods. The aim of this research was to provide reliable data for the analysis of structures damaged by fire. The experimental program used cylindrical concrete test specimens subjected to ISO 834 heating in a furnace up to maximum gas temperatures of 400, 500, 600, 700, and 800 °C. The compressive strength was measured in three situations: (a) at the different temperature levels reached in the furnace; (b) after a natural cooling process; and (c) after aspersion with water at ambient temperature. The results indicate that the concrete residual compressive strength is fairly dependent on the maximum temperature reached in the furnace and revealed that concrete of a lower strength preserved relatively higher levels of strength. The cooling method significantly influenced the strength, albeit at a lower intensity. In all cases, the residual strength remained in the range of 38% to 67% of the strength at ambient temperature. The statistical analysis showed that the data obtained by the experimental program are significant and confirmed the influence of the conditions imposed on the residual strength.Item Análise da infraestrutura de pavimento rígido com reforço diferenciado de fibras de aço.(2017) Maciel, Priscila de Souza; Bezerra, Augusto Cesar da Silva; Bezerra, Augusto Cesar da Silva; Gouveia, Antônio Maria Claret de; Martins, Cláudio JoséAtualmente, os concretos reforçados com fibras curtas de aço são amplamente utilizados no Brasil e no mundo, em especial nas obras de pavimentos e túneis. O uso das fibras de aço em pavimentos de concreto se dá pela necessidade de melhoria da eficiência do concreto em função da sua reduzida capacidade de resistência à tração, consequência da dificuldade em interromper a propagação de fissuras. A fibra atua como ponte de transferência de tensão nos pontos de fissura do pavimento, restringindo a propagação da mesma devido à redução do efeito de concentração de tensões. Neste estudo adotou-se uma faixa com maior volume de fibras na área ínfera da estrutura. Os corpos de prova foram moldados em três modelos: (i) sem fibras, (ii) com fibras distribuídas uniformemente e (iii) com fibras concentradas na área inferior, utilizando concreto com aproximadamente 30MPa de resistência à compressão. Os agregados foram caracterizados quanto à granulometria e massa específica, e as fibras quanto à geometria, resistência à tração e microestrutura. Realizou-se a moldagem de oito corpos de prova cilíndricos (100x200mm) e dois prismáticos (150x150x500mm) para cada modelo. Os compósitos produzidos foram avaliados quanto à resistência à compressão, ao módulo de elasticidade, resistência à tração na flexão, à tenacidade e à absorção de água. A análise da infraestrutura se deu pelo coeficiente de recalque em função da resistência à tração na flexão. Os resultados demonstraram que a configuração de fibras concentradas na parte inferior das peças contribui para o desempenho do concreto.