Flexural Strength of Damaged RC Beams Repaired with Carbon Fiber-Reinforced Polymer (CFRP) Using Different Techniques

Abstract

In this study, an experimental program was developed to investigate the flexural behavior of pre-damaged reinforced concrete (RC) beams that had been repaired and strengthened using carbon fiber-reinforced polymer (CFRP) laminates under a monotonic load. Two techniques were used: externally bonded reinforcement (EBR) and near-surface-mounted (NSM) reinforcement, to repair and strengthen the tested beams. The experimental program involved casting and testing nine simply supported RC rectangular beams; one beam was considered as the reference beam and did not undergo additional strengthening, and the remaining beams were strengthened using CFRP laminates. These eight beams were divided into two main groups for the purposes of strengthening: beams for which the EBR technique was used, and beams for which the NSM technique was used. The primary variables observed in the EBR and NSM groups included four damage percentages obtained according to the preload (20, 40, 60, and 80%) from the ultimate load carried by the reference beam. The experimental results show that decreasing the damage percentage leads to an increase in ultimate strength from about 3.6% to 17.2% for the beams repaired using the EBR technique and from 27.6% to 57% for the beams repaired using the NSM technique; additionally, the NSM method was more effective than the EBR method in terms of the flexural strength and mode of failure. However, using CFRP laminates enhances the flexure capacity of strengthened RC beams.

Investigation of the Experimental Shear Resistance of RC T-beams after Strengthening with Carbon Fiber-Reinforced Polymer (CFRP) Bars

“…The use of CFRP reinforcement demonstrates a diverse array of applications, entailing the construction of innovative structures and the rehabilitation of pre-existing ones [1][2][3][4][5][6][7]. The shear strength of Reinforced Concrete (RC) beams is influenced by many factors [8][9][10]. These factors include the compressive strength of the concrete (f'c), the ratio of main steel (ρ), the dimensions of the beam, the ratio of shear span to effective depth (a/d), and the ratio of shear reinforcement ( v).…”

Investigation of the Stiffness and Ductility of Pre-Cracked RC Beams after repairing with CFRP using Different Strengthening Methods

“…In addition, an Externally Bonded Carbon Fiber Reinforced Polymer (EBR-CFRP) is used to increase the existing structural element's ability to support additional loads. Structure components may be made more robust using CFRP [1][2][3][4][5][6][7][8][9].…”