Projeto de vigas armadas com barras de FRP à flexão: comparativo entre o aço e os diferentes tipos de fibra

Abstract

The use of innovations in civil construction arises from the need to meet demands arising from the increased complexity of structures and the environment in which they are to be inserted, so that the most conventionally used reinforced concrete structures using steel bars do not meet fully comply with all these requests. Thus, this work presents an alternative to be used in reinforced concrete elements, which is the replacement of steel bars by fiber reinforced polymer (FRP) bars. In order to understand the performance of these bars in resistant elements, 72 bi-supported beams were dimensioned in flexion using 4 types of bars: steel, GFRP (polymer reinforced with glass fibers), CFRP (polymer reinforced with carbon fibers) and AFRP (polymer reinforced with carbon fibers). reinforced with aramid fibers). The sections reinforced with steel bars were dimensioned at three different points following the recommendations contained in NBR 6118 (2014), so that after dimensioning the reinforcement was replicated for the beams reinforced with FRP bars, which had their dimensioning done through the recommended practice IBRACON/ABECE CT 303 (2021). After the calculations, a comparison was made between the resistant moment found in the sections using steel bars and for the different types of fiber and it was reached the result that at low rates of reinforcement, the beams armed with FRP bars present a higher value of moment resistant compared to steel that is gradually overcome with the increase of the reinforcement area in the section. Keywords: FRP bars; reinforced concrete beams; bending dimensioning.