Performance of severely damaged reinforced concrete flat slab-column connections strengthened with Carbon Fiber Reinforced Polymer

The punching shear failure of a slab-column connection is a sudden catastrophic failure. The majority of studies have been focused on the strengthening aspects of non-cracked slab-column connections. However, the attention given to the retrofitting of heavily damaged slab-column connections is comparatively less. Therefore, it is crucial to investigate the suitable damage repairing methods as well as post-strengthening methods to enhance performance of damaged slab-column connections. In this study, a total of twenty-six heavily damaged medium-scale flat slab-column connections were repaired using an in-situ chip concrete mixture. Then the damage repaired specimens were retrofitted using alternative arrangements of Carbon Fiber Reinforced Polymer (CFRP) in such a way to investigate the effects of sensitivity of bond parameters on punching shear performance. The punching shear capacity enhancements observed from retrofitted connections were in the range between 20% and 90%.