Iron-based shape memory alloy and fiber reinforced polymers rods for prestressed NSM strengthening of RC beams

Abstract

Abstract The present study involves flexural strengthening of reinforced concrete (RC) beams by prestressed fiber reinforced polymers (FRP) and iron-based shape memory alloys (Fe-SMAs) using the near surface mounted (NSM) technique. ANSYS nonlinear finite element analysis (FEA) software was employed to model RC beams which were validated using the data from an existing experimental study in the literature. Parameters considered were rod length and NSM rod material type under three prestressing levels 20, 30 and 40%. The influence of these parameters on the beams’ load carrying capacity, midspan displacement, ductility index, and failure mode were determined. The results showed that at higher levels of rod prestressing, cracking, yielding, and ultimate load capacities of the beam were improved. However, the displacement was decreased and consequently, the ductility index reduced as prestressing level increased. Furthermore, the Fe-SMA material was able to provide significant ductility. The optimum prestressing level could be identified based on the primary RC beams’ design criteria to either improve load or displacement capacity or both.