Shape memory alloy reinforcement for strengthening of RCC structures—A critical review

Abstract

Significant performance and safety issues can arise from the deterioration of reinforced concrete (RC) structural components brought on by ageing processes and high stress occurrences. Shape memory alloys (SMAs), one of the options for restoring such components, have special qualities including recovering inelastic strain when unloaded (super elasticity) or heated (shape memory effect, SME). To lessen permanent deformations into RC constructions, super elasticity and SME of SMA bars can be used. The stiffness and strength of RC structures can also be improved by the addition of SMAs, allowing them to withstand loads of high intensities with minimal damage. Despite the wide range of studies done on the applications of SMAs in structures, a comprehensive analysis of the present state, key results, potential drawbacks, and future contemplation of SMA bars for the reinforcement of RC structures lacking in the literature. Additionally, detailed instructions for choosing the types and traits of SMAs best suited for a certain strengthening application are lacking. We conducted an extensive examination of the applications of SMA bars in RC beams, in order to fill the basic and practical gaps that were observed. The implementations were investigated from the viewpoints of crack recovery, strength augmentation, confinement, and shear strengthening of new and existing RC structures. The benefits and drawbacks of strengthening with SMAs are then discussed critically, particularly in light of other strengthening techniques and materials. The end of this review highlights the challenges of using SMAs as well as potential future opportunities that might arise from their effective use of RCC.