Description
Low-cost iron-based shape memory alloys (Fe-SMAs) have emerged as a viable alternative to carbon fiber reinforced polymers (CFRP) for near-surface mounted strengthening of reinforced concrete (RC) structures, particularly due to their ease of prestressing and their plastic behavior similar to reinforcing steel. The short-term behavior has already been investigated in detail, yet the durability of such systems still remain a relatively unexplored area, as there is a scarcity of long-term experimental studies available. To address this gap, two RC beams strengthened with NSM Fe-SMA were subjected to natural environmental conditions for an extended period of 8 years, during which they were subjected to sustained loading beyond their cracking load level. Subsequently, the beams were subjected to four-point bending loading until failure. Results were compared with a previous short-term study involving identical specimens that had not been exposed to environmental factors or sustained loading. A comprehensive cross-section analysis (CSA) further complements the experimental results, which effectively captured both the long-term and bending behavior. Influence of concrete creep and shrinkage, as well as Fe-SMA relaxation is discussed by employing the CSA. Lastly, influential parameters and their impact on structural performance were identified via sensitivity analysis.
