Buckling of steel and Ni-Ti reinforcements in very high performance concrete (VHPC) elements

For all these reasons, VHPC elements with Ni-Ti reinforcements were studied. The results of an experimental campaign of VHPC columns are shown in this article. The VHPC columns were subjected to monotonic loading where the main goal was to study compressed steel reinforcement buckling. The results of these tests were also used to extend the mixed model proposed by Pereiro-Barceló and Bonet (2017), which determines the buckling critical stress for any transverse reinforcement separation and considers the effect of the concrete cover (with and without steel fibres). This model was recalibrated to consider elements made of VHPC. Besides, specimens made of either High Performance Concrete (HPC) or VHPC, and with Ni-Ti reinforcements, were also tested to study the behaviour of compressed Ni-Ti reinforcements in elements made of high strength fibre-reinforced concrete.