Feasibility of using aluminum alloy bars as near-surface mounted reinforcement for flexural strengthening of reinforced concrete beams

摘要

Aluminum alloys (AAs) possess various advantageous properties such as good corrosion resistance and high ductility and have recently gained interest in strengthening reinforced concrete (RC) structures. This paper investigates the potential application of AA bars as the near-surface mounted (NSM) reinforcement in flexure strengthening of RC beams. A total of seven RC beams including one reference specimen and six specimens strengthened with NSM AA bars were designed and loaded monotonically up to failure. The tensile steel reinforcement ratio, NSM reinforcement ratio, precracking load, and bonding area of NSM reinforcement were selected as the main test variables. Results suggest that both the flexural capacity and stiffness of the strengthened beams improved with the use of NSM AA bars compared to the reference beam, and all the strengthened concrete beams exhibited a ductile failure mode. Nevertheless, increases in flexural load carrying capacities were modest when the AA bars were used as NSM reinforcement. Furthermore, an analytical model, which combined the sectional analysis method and interfacial stress analysis model, was developed to predict the load versus mid-span deflection relationship of the concrete beams strengthened with NSM AA bars. The developed model was also capable of predicting the load-strain relationships in AA reinforcement. Good agreements were achieved between the analytical results and experimental results.