Retrofitting of punching shear damaged flat slabs using carbon fiber reinforced polymer (CFRP) sheets

Abstract

The punching shear failure of flat slabs is common in reinforced concrete buildings, and once the failure occurs, rectification is difficult and time consuming, which also affects building functionality. Hence, it is convenient to retrofit the flat slab structure to enhance the punching shear capacity while minimizing the disturbance to the structure. Therefore, a method was developed to retrofit punching shear damaged flat slabs using Carbon Fiber Reinforced Polymer (CFRP) sheets, considering the advantageous properties of the material, like the flexibility of usage, less weight, less thickness of material etc. Thus, experimental and theoretical studies were carried out using 12 numbers punching shear failed flat slab panels with various repair materials and various CFRP sheet arrangements. The BS EN 1992-1-1: 2004 standard was used for theoretical analysis. A comparison of theoretical and experimental punching shear capacities concluded that the theoretical capacity is much higher than the experimental capacity, due to the difference of failure modes of the specimens.