Resistant shear of concrete beams with the addition of steel fibers when reinforced with carbon fiber

Abstract

Structural reinforcement encompasses many challenges. If a structural element is damaged by some external factor and is not reinforced, failure can be immediate. The research presents a method of repairing and reinforcing structures by applying carbon fiber, to determine the increase in resistance to shear force. As elements that do not have twist at the node are required to evaluate their shear resistance, six reinforced concrete frames were made, incorporating three steel fibers. After the shear test and reaching their ultimate failure, they were repaired with SikaRep 500 and reinforced with carbon fiber; For the shear test, the load was applied at a distance equal to the effective superelevation. It is concluded that the average resistance in beams with simple reinforcement without the addition of steel fiber, when repaired and reinforced with carbon fiber, was 8.56 MPa, in the initial stage it was 3.91 MPa and in the beams with fiber addition of steel was 9.19 MPa and in the initial stage it was 5.18 MPa. The average deformation in beams with simple reinforcement without the addition of steel fiber, when repaired and reinforced with carbon fiber, was 6.62 mm and in the initial stage it was 2.40 mm, while, in the beams with fiber addition of steel was 9.26 mm and in the initial stage it was 3.00 mm. Demonstrating that the use of carbon fiber as reinforcement increases the initial shear resistance by up to 2.19 times.