Shear Capacity of Reinforced Concrete Flat Slabs Made with High-strength Concrete: A Numerical Study of the Effect of Size, Location, and Shape of the Opening (TECHNICAL NOTE)

Nowadays, concrete with strength higher than 50 MPa is utilized due to the ever increasing need for higher strength and prolonged healing properties. Despite the widespread use of high-strength concrete, only a few research projects have been conducted on the punching shear strength of high-strength concrete slabs. Reinforced concrete flat slabs are widely employed in structural systems. The location of the slab-column connection is the most sensitive part of the flat slab. The present study investigates the effect of existance of opening in reinforced concrete flat slab in two groups of slab, a group with HSC concrete and the other with NSC concrete. To this end, a few examples of flat slabs with different positions, shapes, and dimensions of the opening with normal-strength concrete and, the slabs with the same geometry but high-strength concrete are compared so as to review the effect of high-strength concrete on the slabs with different openings. The results of this research show that the high-strength concrete improves the shear capacity of the slabs and leads to transferring higher forces in slab-column connection. Furthermore, the dimensions, shape, and position of the opening is effective on the percentage of load increase and ultimate deflection of samples.