Recent Advancements in Development and Application of an Iron-based Shape Memory Alloy at Empa.

The Fe-SMA developed at the Swiss Federal Laboratories for Materials Science and Technology (Empa) has an alloy composition of Fe-17Mn-5Si-10Cr-4Ni-1(V,C) and exhibits an excellent shape memory effect on heating at 160 °C or above. The shape memory effect feature equips Fe-SMA with a unique self-prestressing ability that can be exploited for many civil engineering applications. In addition to the self-prestressing ability, Fe-SMA has a high elastic modulus (165 GPa), low cost, and high machinability compared to the nickel and copper-based SMAs, which makes it more suitable for structural applications. The current work aims to provide an overview of the recent advancements in the research and development of Fe-SMA at Empa. To this end, the advancements related to the material development, applications of Fe-SMAs in prestressing reinforced concrete (RC) and metallic structures, and  the introduction of Fe-SMA reinforcements to the market alongwith some recent field applications are presented. The paper concludes with an overview of the opportunities and challenges associated with using Fe-SMA reinforcements in civil infrastructure.