2023-06-262023-06-262023-03-07SANTOS, J. R. Estudo reológico de pastas e concretos de cimento portland: avaliação da eficiência de aditivos químicos e do teor de sílica ativa. 2023. 210 f. Dissertação (Mestrado em Geotecnia, Estruturas e Construção Civil) - Universidade Federal de Goiás, Goiânia, 2023.http://repositorio.bc.ufg.br/tede/handle/tede/12912Studies of rheology and optimization of Portland cement mixtures can play an important and prominent role in the correlation with performance, mechanical behavior, high durability and service life in the hardened state of concrete. The present work encompasses stages of rheological characterization of Portland cement pastes, with the aim of evaluating the intervention of chemical admixture and silica fume contents (8%, 10% and 12%) in two water/binder ratios (0.40 and 0.55). Additionally, these variables were also analyzed in concrete, measuring the rheometric parameters, basic mechanical behavior properties (compressive strength and modulus of elasticity) and water absorption. In addition, the chemical admixtures were characterized physic-chemically and the validation of a technical instruction for conducting rheology tests on pastes was proposed. As a result, the superplasticizer type admixtures and those with higher solids content exhibited better behavior in the viscosity properties and shear rate of the pastes. The 8% silica fume content was more interesting in terms of mechanical behavior and water absorption. The paste results were coherent with the results obtained from the concretes.Attribution-NonCommercial-NoDerivatives 4.0 InternationalReologiaReômetro rotacionalPlastificanteSuperplastificanteSílica ativaPasta de cimentoConcretoRheologyRotational rheometerPlasticizerSuperplasticizerSilica fumeCement pasteConcreteENGENHARIAS::ENGENHARIA CIVIL::GEOTECNICADissertação