Feasibility of iron-based shape memory alloy strips for prestressed strengthening of steel plates

Iron-based shape memory alloys (Fe-SMAs) are advanced materials that can be used as prestressing elements for strengthening and rehabilitation of civil structures. In this paper, the results of a feasibility study on the application of shape memory effect (SME) of Fe-SMA strips for prestressed strengthening of steel plates are provided and discussed. The Fe-SMA strips were anchored to the steel plates using a pair of mechanical anchorage system. Electrical resistance heating (ERH) technique was then used to heat up the Fe-SMA strips to 260 °C, resulting in activation of the Fe-SMA material. The activated Fe-SMA strips apply a prestressing force to the steel plate. The Fe-SMA-strengthened steel plates were then subjected to static tensile load to simulate the external loading on the retrofitted member. Based on the preliminary experimental results, it can be concluded that strengthening of steel plates with activated Fe-SMA strips can considerably decrease the tensile stress level in such members.