Smart and Emerging Materials

Shape memory alloy (SMA) has been attracting the researchers from different fields due to their superior properties. The SMA is a unique class of alloy with the ability to undergo large deformation as well as energy dissipation capacities while maintaining a super-elastic response and return to its original shape through stress removal (super elasticity) or heating (shape memory effect). SMA as internal reinforcement: The superior properties of SMA make it a good reinforcement candidate for the use in the seismic design of structures. The exceptional property of SMA in recovering substantial inelastic deformation upon unloading makes it very beneficial in seismic design. Thus, if SMA is used at the location of plastic hinges with proper design limitations, the structure will dissipate the demand energy and return to its original shape when unloaded. The design of self-centering concrete beam-column connections reinforced using SMA is an innovative proposal and can be optimized for the use in real-life construction. SMA in strengthening applications: Besides the material super-elasticity, corrosion and fatigue resistivity, SMA is mainly characterized by the shape memory effect that represents the ability of the SMA to recover its original shape after being deformed beyond the elastic limits through heating. The strain recovered in this transformation process can be utilized for pre-stressing applications by eliminating the use of hydraulic jacks. By having the pre-strained SMA reinforcement attached to the RC members and then applying heat above the activation temperature the SMA will recover the inelastic strain and thus a pre-stressing force will be developed in the RC member. The pre-strained SMA itself can be used as the pre-stressed reinforcement in flexural strengthening of RC beams as well as active confinement of RC columns.