Experimental study on concrete beams reinforced with pseudoelastic Ni-Ti continuous rectangular spiral reinforcement failing in shear

Shear failures in reinforced concrete beams are associated with brittle collapses, practically without reaction capacity by users, which may be associated with human and material losses. This behavior is related to low deformations at failure, which makes predicting failure difficult. Ni-Ti is the most commonly used shape memory alloy and is an exceptional material that has the ability to achieve high deformations and to return to a predefined shape after unloading or upon heating. An experimental campaign focused on assessing the possibility of obtaining more ductile shear failures using a Ni-Ti alloy reinforcement that shows pseudoelasticity at ambient temperature is presented. Seven small-scale reinforced concrete beams were tested to assess the feasibility of this idea. It is shown that the Ni-Ti spiral reinforcement makes it possible to obtain highly deformable concrete elements even for beams failing in shear.