Description
Punching shear failure causes a sudden and brittle collapse in column-supported reinforced concrete slabs, which can occur due to increased loading, design and construction deficiencies, or long-term degradation of the structural system. Recently introduced innovative materials aim to improve strengthening methods, minimizing disruptions for building owners. Among these materials, iron-based shape memory alloys (Fe-SMA) show promise for effectively reinforcing and prestressing existing concrete structures.
Based on the authors' experience in structural assessment and strengthening of existing buildings and parking garages, two specific applications are presented: strengthening with Fe-SMA bars in the hogging moment region to enhance the slab's bending resistance above the column, and in the sagging bending region to transfer moments while preventing plastic moment redistribution. Both case studies include punching shear calculations following Level III/IV approximations according to fib model code.
This paper highlights the practical and effective use of iron-based shape memory alloys in addressing punching shear deficiencies in existing concrete slabs, offering a valuable solution to enhance the safety and performance of RC structures.
