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.

EBR Strengthening Technique for Concrete, Long-Term Behaviour and Historical Survey.

Epoxy bonded steel plates (externally bonded reinforcemen: EBR) for the strengthening of concrete structures were introduced to the construction industry in the late 1960s, and the use of fibre reinforced polymers (FRPs) was introduced in the 1990s, which means that these techniques have already been used in construction for 50 and 25 years, respectively. In the first part of the paper, a historical survey of the development and introduction of these strengthening techniques into the construction industry are presented. The monitoring of such applications in construction is very important and gives more confidence to this strengthening technique. Therefore, in the second part of the paper, two long-term monitoring campaigns over an extraordinarily long duration will be presented. Firstly, a 47-year monitoring campaign on a concrete beam with an epoxy bonded steel plate and, secondly, a 20-year monitoring campaign on a road bridge with epoxy bonded CFRP (carbon fibre reinforced polymers) strips are described. The paper is an expanded version of the paper presented at the SMAR2017 Conference.