DEDICATÓRIAS Dedico este trabalho à minha amada família, em especial aos meus filhos, Daniel, Davi, Laís, e ao meu marido, Lucas, pela compreensão, carinho e apoio ao longo da elaboração deste trabalho. Palavra-Chave: Concreto reforçado com fibras. Ensaio de duplo puncionamento. Sistemas de controle de ensaio. ABSTRACT A quality control model is reliable when properly linked to a structural design model. The fib Model Code 2010 presented a design model of fiber reinforced concrete (FRC) for

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... ctural applications where the control of the material is based on the notched beam test (EN 14651). However, this Code indicates that other test methods can be applied as long as proven correlation with the reference method. There are obstacles to the use of the EN 14651 test method in Brazil, as it requires sophisticated testing machines that are difficult to find in laboratories dedicated to quality control. The double punch test is as an alternative test method to control the mechanical behavior of FRC and requires simpler test machines. However, some studies have observed post- peak instabilities in FRC with high matrix strength and low post-crack residual strength low fiber contents are used. These instabilities occur due to some factors including the test control system. The instabilities may compromise the evaluation of the material. Thus, this research studied the control systems for the double punch test. Tests were performed in open and closed-loop test machines and with control by machine displacement and by deformation of the specimen to verify if the instabilities caused after the matrix cracking compromise the determination of residual strength. Results showed that when open-loop test machines are employed, post-crack instability is greater. However, it does not influence the determination of residual strength negatively. Therefore, the double punch test, even when performed in openloop test machines, may be used for the routine analysis and characterization of FRC, establishing as control parameters residual forces values for certain axial displacement.