Study On Reinforced Concrete Slabs And Steel Fiber Reinforced Concrete Slabs Subjected To Punching Shear

The flat-plate structures has more than 100 years of history and as many advantages it has becoming increasingly wide of applications. But the biggest weakness is the punching shear failure at the slab-column connections. As the punching shear failure is brittle failure and may lead to a chain reaction of the overall collapse, so as to this type structural ,one of the critical point is how to prevent punching failure and how to enhance the punching shear capacity. The main research work aiming to the slab-column connections covers the following aspects:First, analyse the mechanisms involved in flexural failures and punching shear failures that the plates may be occurred in slab structures; According to the comparing of different code equations and the failure process, obtain the main influencing factors and the corresponding optimum measure form. Discuss the methods of enhancing performance of slab-column connections and point that the use of steel fiber is the more practical approch.Second, the resistance to flexural failures are calculated by yield line theory. The ultimate punching shear strength of reinforcement concrete slabs which is supposed to be applied by the concrete part and reinforcement part is obtained by using twin-shear unified strength theory and the reinforcement's dowel reaction. Then give the equation to distinguish the failure model of the slab.Based on the above work, the ultimate punching shear strength of steel fiber reinforcement concrete slabs is obtained.Last, the further research on the two type slabs are started by finite element program ANSYS, derive the punching shearing strength and load-deflection curve with different contains of reinforcement , steel fiber and different use range of steel fiber.