2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference

Experimental Investigation on Punching Behavior of GFRP-RC Edge Flat Plate Connections with and without Shear Reinforcement

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Dr. Brahim Benmokrane, Universite de Sherbrooke
Mr. Ahmed E. Salama, Sherbrooke university (Presenter)
Dr. Mohamed Hassan, Université de Sherbrooke

This paper presents an experimental investigation to study the effects of GFRP flexural reinforcement ratio and spiral stirrups as shear reinforcement on the punching-shear behavior of edge flat plate connections reinforced with glass fiber-reinforced polymer (GFRP) bars. Three full-scale specimens were tested under combined vertical shear force (V) and unbalanced moment (M) with (M/V) ratio equal 0.3. The slabs measured 2,500×1,350×200 mm with a 300-mm square column extending 700 mm above and below the slab surfaces. Two connections were reinforced with GFRP bars without shear reinforcement while one connection was reinforced in shear with four branches glass-FRP spiral stirrups placed in orthogonal layout at a distance of 4.25d. The test results revealed that increasing the reinforcement ratio from 1.03 to 1.55% increased the punching shear strength by 21% while the deformation capacity was decreased by 62%. Utilizing spiral stirrups around the punching shear zone showed substantial improvement on the slab behavior, whereas the mode of failure was changed from a brittle punching failure for slab without shear reinforcement to a softer punching failure for slab with shear reinforcement. Besides, the punching shear strength and deformation capacity were increased by 55% and 225% compared to their counterpart without shear reinforcement, respectively.