Punching shear strength of reinforced concrete slabs strengthened with glass fiber-reinforced, polymer laminates

This study investigates the punching shear strength and failure behavior of reinforced concrete slabs strengthened with glass fiber-reinforced polymer (GFRP) laminates. The parameters of the 18 specimens.studied herein are concrete compressive strength, steel reinforcement ratio, and the number of GFRP laminate layers. The specimens were tested simply supported along the four sides of the slabs and loaded through the stub column. The behavior of the concrete slabs reinforced with GFRP laminates in addition to steel reinforcement is compared to that of slabs with steel reinforcement. Experimental test results indicate that applying GFRP laminates markedly increases the punching shear capacity of slab-column connections. Based on these results, a design procedure is presented to calculate the ultimate punching shear strength of slab-column connections strengthened by the GFRP laminates. Good correlations between predicted and experimental results have been achieved.