Experimental study on enhancement of self-restoration of concrete beams using SMA wire

TLDR: In this paper, the self-restoration capacity of a mortar beam with shape memory alloys (SMA) reinforcements was evaluated. And the results were compared with those for a beam containing steel wires, showing that after maximum deflection, the mortar beam can return to an about one-tenth deflection compared with the maximum.

Abstract: Shape Memory Alloys (SMA) exhibit stable superelasticity between a reverse transformation finish temperature (Af) and approximately 30°C above Af, and therefore can sufficiently work as a superelastic material for structural use in building under the temperature in a construction environment. In order to verify the potential self-restoration capacity of mortar beams containing superelastic SMA reinforcements, static loading tests were conducted, and the results were then compared with those for a beam containing steel wires. The comparison indicates that (1) after maximum deflection, the mortar beam with SMA can return to an about one-tenth deflection compared with the maximum, (2) the range of deflection of the mortar beam with SMA is more than seven times that of the beam with steel, and (3) wide single crack can occur at the critical section due to a weaker bond force between SMA and mortar.