An experimental study on self-centering and ductility of pseudo-elastic shape memory alloy (PESMA) fiber reinforced beam and beam-column joint specimens

The use of energy dissipating materials both as reinforcement and as external devices for passive control of reinforced concrete structures is a widely accepted method in the construction industry. The present technologies have some limitations related to ageing, durability, corrosion and geometry restoration after strong events (for example, yielding in steel). An alternative reinforcement material such as shape memory alloy (SMA) could offer scope for having large recoverable deformations (self-centering ability), thus improving performance especially after a severe loading has occurred. In addition to enhancing the ductility of reinforced concrete, they can provide a wide range of performances, from full self-centering to high energy dissipation capabilities, as well as high resistance to large strain cycle fatigue and better durability. This paper reports on several experiments and analyses for evaluating the self-centering ability, ductility of beams and beam-column joint achieved by randomly distributed pseudoelastic SMA (PESMA) fibers. Three point loading experiments on prisms and specially designed prototype beam-column joint specimens with steel and PESMA fibers show that the ductility and self-centering ability of the composite with PESMA fibers is far superior to that of the steel fibers.