Iron-Based Shape Memory Alloys in Construction: A Review of Research, Applications, and Challenges
Marlon Hilscher, Paul Jübner, Elyas Ghafoori
Abstract
Abstract Iron-based shape memory alloys (Fe-SMAs) are emerging as smart, high-performance materials with transformative potential for structural applications in civil engineering. Leveraging their unique thermomechanical properties (shape memory effect and superelasticity) Fe-SMAs enable innovative solutions for prestressing, strengthening, and retrofitting structural components. This review presents a comprehensive overview of recent advances in Fe-SMA development and their integration into strengthening systems for concrete and steel structures, particularly within the field of construction. Various installation methods are examined, including adhesive bonding, mechanical clamping, bolting, and nailing, highlighting their practicality and effectiveness across construction applications. Special attention is given to the fatigue performance of Fe-SMAs, particularly transformation-induced stress relaxation and its thermal reactivation to restore lost prestress. The review covers applications in concrete, steel, composite, and glass structures, supported by real-world implementations in buildings and bridges for retrofitting, strengthening, and fatigue crack repair. Emerging uses such as Fe-SMA couplers and their role in 4D printing for adaptive infrastructure are also discussed. In addition to summarizing current knowledge, the review identifies key research gaps and outlines directions for future study—including long-term durability, prestress retention, environmental performance, and corrosion resistance. This work aims to support both academic research and industrial adoption of Fe-SMAs as next-generation materials for smart, resilient, and sustainable construction.