Análise comparativa do dimensionamento à flexão de vigas de concreto armado com barras de aço e de fibra de vidro: ênfase na deformação máxima

Abstract

This work presents a comparative analysis of the flexural behavior of reinforced concrete beams with two distinct types of reinforcement: conventional steel bars and glass fiber reinforced polymer (GFRP) bars. The main objective is to establish a relationship between structural solutions, in order to obtain similar maximum strains, evaluating the feasibility of using GFRP as an alternative to steel in certain applications. For this, six beams were designed based on Brazilian and American standards, three of which were reinforced with conventional steel and three reinforced with GFRP bars. The prototypes were submitted to four-point flexural tests, observing the maximum test load and the displacements in the center of the beams during the test, as well as the characteristic compressive strength of concrete in cylindrical specimens. The analysis of the experimental results made it possible to compare the structural performance of the two solutions. The data obtained allowed us to conclude that the replacement of steel bars by fiber bars is feasible, as long as certain proportions are respected. In this study, in order to obtain similar strains, it is necessary that the GFRP area is approximately three times larger than that of steel (1:3 ratio), and that the concrete section is increased by about 33% (1:1.33 ratio). These results highlight the potential of GFRP as an alternative material to steel in projects that require high durability and corrosion resistance.