5. SMA Composite Reinforcement for Concrete Structures

Fiber-reinforced polymer (FRP) reinforcing bars have been utilized in concrete structures as an alternative to traditional steel reinforcement to combat corrosion issues. However, they are seldom taken into consideration in structures that require ductility and damping features because of the linear behavior of the typically utilized reinforcing fibers. This issue might be resolved by using superelastic shape memory alloy (SMA) fibers as reinforcement in the composite due to their nonlinear-elastic behavior. SMA-FRP composite is created by coupling small-diameter SMA wires with a polymer matrix. In this chapter, we explore the use of SMA-FRP bars to improve the seismic and cyclic performance of reinforced concrete (RC) structures by mitigating residual deformations while preserving the elastic properties associated with traditional FRP. The work presented herein includes discussing the fabrication of SMA-FRP bars, the experimental cyclic behavior of RC components reinforced with SMA-FRP bars, and the seismic behavior of RC moment resisting frames reinforced with SMA-FRP under sequential main shock-aftershock seismic excitations.