Avaliação de retração e fluencias do concreto auto-adensavel para aplicação em elementos pre-moldados
Andre Luiz Nonato Ferraz
TESE
Português
T/UNICAMP F413a
[Evaluation of shrinkage and creep of self-compacting concrete for application in precast elements]
Campinas, SP : [s.n.], 2009.
253 p. : il.
Orientadores: Newton de Oliveira Pinto Junior, Monica Pinto Barbosa
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Resumo: Foram avaliados neste trabalho, teórica e experimentalmente, o comportamento reológico e mecânico do concreto auto-adensável (C.A.A.), em específico suas características frente as deformações lentas, retração e fluência, e sua aplicabilidade em peças pré-moldadas. Foram desenvolvidos duas...
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Resumo: Foram avaliados neste trabalho, teórica e experimentalmente, o comportamento reológico e mecânico do concreto auto-adensável (C.A.A.), em específico suas características frente as deformações lentas, retração e fluência, e sua aplicabilidade em peças pré-moldadas. Foram desenvolvidos duas composições de concreto de classes de resistência distintas, 35 e 55 MPa. Na etapa de dosagem foram utilizados os procedimentos do método REPETTE-MELO, onde nas pastas e argamassas, foram realizados ensaios reométricos, ensaios de fluidez e Mini-Slump, e na definição do traço do C.A.A., ensaios de controle, tais como Slump-Flow, Funil em V, caixa em L, caixa em U e tubo em U, assim como ensaios das propriedades mecânicas tais como resistência à tração, resistência à compressão, e módulo de elasticidade. A avaliação do comportamento dos concretos frente a fluência se deu nas idades de 7, 14, 28, e 56 dias, segundo a NBR 8224 (ABNT, 1983), e frente a retração de acordo com a norma MERCOSUL NM 131:9. Os resultados experimentais foram comparados com valores de concretos convencionais disponíveis na literatura. Todos os ensaios foram realizados no Laboratório CESP de Engenharia Civil, e no Laboratório de Hidrologia da UNESP em Ilha Solteira-SP. No estudo da deformação rápida, ensaios de tração na flexão foram realizados aos 28 e 56 dias. Os coeficientes de fluência foram calculados quer seja através dos valores experimentais como pela NBR 6118 e comparados entre si, apresentando boa correlação, com diferenças menores que 10% para toda as idades. A composição do concreto auto-adensável foi implantada para fins de avaliação, junto a empresa de Pré- Moldados Protendit de São José do Rio Preto-SP, onde foram moldadas vigas, em escala real, as quais apresentaram melhor acabamento e se mostraram 50% mais economicas, em relação a mão-de-obra, quando comparada com a viga de concreto convencional. Os resultados obtidos mostram que as composições de concreto auto-adensável apresentam maiores valores de retração e fluência quanto comparados com concretos convencionais de mesma resistência mecânica. O C.A.A. de resistência à compressão igual a 55 MPa apresentou menor retração e fluência básica que o C.A.A. de resistência 35 MPa.
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Abstract: This project analyzed, theoretically and experimentally, the mechanical and rheological behavior of the selfcompacting concrete (C.A.A.), specially its features according to slow deformation, shrinkage and creep, and its applicability in precast elements. Two compositions of
concrete of... Ver mais Abstract: This project analyzed, theoretically and experimentally, the mechanical and rheological behavior of the selfcompacting concrete (C.A.A.), specially its features according to slow deformation, shrinkage and creep, and its applicability in precast elements. Two compositions of
concrete of different classes of resistance were developed, 35 MPa and 55 MPa. In the stage of the dosage, the procedures of the method REPETTE-MELO were used, rheometrical tests, fluidness tests and Mini-Slump were carried out on the pastes and the mortars, and control tests, such as Slump-Flow, funnel V test, box L, box U and tube U, and mechanical properties tests, such as tensile strength, compression strength and elasticity module were used to define the C.A.A. feature. The evaluation of the concrete behavior by creep happened at ages of 7, 14, 28, and 56 days, according to NBR 8224 (ABNT, 1983), and by shrinkage according to MERCOSUL NM 131:9. The experimental results were compared with values from conventional concrete available in the literature. All tests were performed at CESP Civil Engineer Laboratory, and at Hydrology Laboratory of the UNESP in Ilha Solteira-SP. In the fast deformation study, traction tests in flexion were performed at 28 and 56 days. The creep coefficients were calculated either through experimental values as by the NBR 6118 and compared each other, showing a good correlation, with differences smaller than 10% for all ages. The composition of self-compacting concrete was established for evaluation, in partnership with precast elements company Protendit of São José do Rio Preto-SP, where were shaped beams, in real scale, which showed better finishing and they showed themselves 50% more economical regarding labor, when compared with conventional concrete beam. The results reached show that the compositions of self-compacting concrete present higher values of shrinkage and creep when compared with conventional concrete of same strength. The C.A.A. that presented compression strength equal to 55 MPa showed a lower shrinkage and basic creep that C.A.A. strength of 35 MPa. Ver menos
concrete of... Ver mais Abstract: This project analyzed, theoretically and experimentally, the mechanical and rheological behavior of the selfcompacting concrete (C.A.A.), specially its features according to slow deformation, shrinkage and creep, and its applicability in precast elements. Two compositions of
concrete of different classes of resistance were developed, 35 MPa and 55 MPa. In the stage of the dosage, the procedures of the method REPETTE-MELO were used, rheometrical tests, fluidness tests and Mini-Slump were carried out on the pastes and the mortars, and control tests, such as Slump-Flow, funnel V test, box L, box U and tube U, and mechanical properties tests, such as tensile strength, compression strength and elasticity module were used to define the C.A.A. feature. The evaluation of the concrete behavior by creep happened at ages of 7, 14, 28, and 56 days, according to NBR 8224 (ABNT, 1983), and by shrinkage according to MERCOSUL NM 131:9. The experimental results were compared with values from conventional concrete available in the literature. All tests were performed at CESP Civil Engineer Laboratory, and at Hydrology Laboratory of the UNESP in Ilha Solteira-SP. In the fast deformation study, traction tests in flexion were performed at 28 and 56 days. The creep coefficients were calculated either through experimental values as by the NBR 6118 and compared each other, showing a good correlation, with differences smaller than 10% for all ages. The composition of self-compacting concrete was established for evaluation, in partnership with precast elements company Protendit of São José do Rio Preto-SP, where were shaped beams, in real scale, which showed better finishing and they showed themselves 50% more economical regarding labor, when compared with conventional concrete beam. The results reached show that the compositions of self-compacting concrete present higher values of shrinkage and creep when compared with conventional concrete of same strength. The C.A.A. that presented compression strength equal to 55 MPa showed a lower shrinkage and basic creep that C.A.A. strength of 35 MPa. Ver menos
Pinto Júnior, Newton de Oliveira, 1951-
Orientador
Barbosa, Monica Pinto
Coorientador
Repette, Wellington Longuini
Avaliador
Carvalho, Roerto Chust de
Avaliador
Camarini, Gladis, 1958-
Avaliador
Avaliação de retração e fluencias do concreto auto-adensavel para aplicação em elementos pre-moldados
Andre Luiz Nonato Ferraz
Avaliação de retração e fluencias do concreto auto-adensavel para aplicação em elementos pre-moldados
Andre Luiz Nonato Ferraz
Exemplares
Nº de exemplares: 2
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