Investigation the Flexural Behavior of Reinforced Concrete Beams with Steel and FRP Rebars Strengthened by CFRP Laminates

Nowadays, using FRP materials as reinforcing rebars in concrete structures, bridge decks and roads is common to prevent rusting of steel rebars. The purpose of this study was to strengthen the flexural strength of the concrete beams with FRP rebars and also to improve the weak beams that were reinforced with these rebars and reinforced by attaching the CFRP Laminates in the lower part of the beam along its length. For this purpose, two main parameters of ductility and flexural strength of sections reinforced with FRP rebars, designed in 12 models and subjected to nonlinear static analysis (pushover) in ABAQUS software and then the GFRP sample is also subjected to cyclic loading. The results show that to reinforce the beams if these rebars are used in the absence of steel bars, it is better to use the AFRP rebar because it provides flexural strength of beam sections about 8 to 18% more than the sections reinforced with CFRP and GFRP rebars and if the ductility is considered, It is advisable to use GFRP rebar which has about 7-15% more ductility than AFRP and CFRP sections, and if the weak section is strengthened with CFRP Laminates under cyclic loading, the flexural capacity can be more than 2.28 times to the nonlinear static analysis (pushover).