Finite Element Analysis of Flexural Strengthening of Reinforced Concrete Beams Using Near-Surface Mounted CFRP Rebars

Abstract

Most of the standing structures today have already deteriorated or are on the verge of deterioration due to an increase in their age and harsh environmental conditions. For this very reason, the structures are in need of being upgraded or replaced. Retrofitting using near-surface mounted (NSM) fiber-reinforced polymer (FRP) rods has now emerged as a promising technique for strengthening the reinforced concrete members by increasing their flexural strength. This study aims to numerically investigate the efficiency of the NSM technique for flexural strengthening of RC beams by using finite element (FE) software, ABAQUS, and also evaluate the impact of variables such as concrete strength, embedded length of FRP rods, filler material used for the FRP rods, and the number of FRP rods provided. Validation of the finite element model was confirmed by first making a comparison with the experimental study presented in the literature for an un-strengthened beam. Thereafter, the validated model was used to simulate reinforced concrete beams strengthened with the NSM technique. The numerical results of the cracking moment, steel yielding moment, ultimate bending moment, and deflection at failure were reported and the impact of the variables was evaluated. The FE analysis results indicated that for the RC beams strengthened with NSM FRP rods, the flexural capacity significantly increased compared to the control beam, while the mid-span deflections of strengthened beams at failure decreased compared to the control beam.