Investigation of the effect of CFRP bars on punching shear capacity in Reinforced Concrete (RC) flat slabs

The present study deals with the punching shear capacity of reinforced concrete (RC) flat slabs reinforced with Fiber Reinforced Polymer (FRP) bars. A total of 49 reinforced concrete (RC) column-slab connections were simulated using ABAQUS finite element software. The numbers of six interior column-slab connections, five edge column-slab connections, and three corner column-slab connections were selected from the previous test results and were simulated to evaluate the software's ability. The simulation results were so satisfactory in terms of failure mode, initial and propagation of cracks that the tested to simulated punching shear capacity of interior and edge column-slab connections were about 0.86 to 0.92, 0.85 to 0.95, and 0.91 to 0.95 respectively. The punching shear capacity was predicted by ACI 440.1R-15, CSA S806-12, JSCE-97, and BSI 8110-97. The punching shear design equation based on ACI 440.1R-15 underestimated the punching shear capacity with 2.91 to 4.75 (Interior column-slab connections) and 2.01 to 2.99 (Edge column-slab connections), respectively. The numbers of 23 specimens were simulated to investigate the punching shear capacity of reinforced concrete (RC) flat slabs with carbon fiber-reinforced polymer (CFRP) reinforcing bars. The results showed that the replacement of CFRP bars instead of GFRP bars has played a significant role in increasing the punching shear capacity of reinforced concrete (RC) column-slab connections. To investigate the effect of increasing slab thickness, the numbers of six specimens were simulated. With increasing the thickness of the flat slab, the punching shear capacity will increase from 27.05% to 49.50%. It should be noted that with the increase of column dimensions in the form of simulation of six specimens, the punching shear capacity of the specimens has increased about 11.84% to 17.89%.