Reinforced Concrete Beams Strengthened in Flexure with Near-Surface Mounted 7075 Aluminum Alloy Bars

Abstract

The flexural behavior of reinforced concrete (RC) beams strengthened with near-surface mounted (NSM) 7075 aluminum alloy (AA) bars was investigated through experimental testing. In particular, 10 RC beams strengthened with NSM AA bars and one control beam were tested under four-point bending loading. The experimental variables included NSM reinforcement ratio, bonded length of NSM reinforcement, end anchoring of NSM reinforcement, and type of bonding agent. The test results were evaluated in terms of the load-deflection curves, failure modes, ductility, and strains in NSM reinforcements, and the effects of different test parameters on the effectiveness of the proposed strengthening approach were discussed. In addition, analytical models were developed to predict the load-bearing capacities of strengthened beams failed by intermediate crack debonding and concrete cover separation, respectively. The RC beams strengthened with NSM AA bars exhibited a significant improvement in maximum load ranging from 35% to 120% over the reference specimen.