Punching strength of conventional reinforced concrete flat slabs

Abstract

The paper presents comparison between the punching shear calculations from six different codes and two equations from the literature. It utilizes 257 punching tests data collected from the literature. The concrete strengths, f'c, range between 12.3 MPa and 68 MPa, the reinforcement ratios range between 0.2% and 5.01%, and the slab depths range between 80 mm and 500 mm. It is found that the smallest error is for CEB-FIP-90 and EC2-2004 while the largest error is for JSCE-2002 and ACI318-19. Also, modifications to one of the equations of the Egyptian reinforced concrete code and two of the equations of ACI318-19 code for calculating the punching strength of flat plates without shear reinforcements are presented. The modified Egyptian and ACI318-19 codes equations for punching strength are compared to the experimental data and good correlations are noticed. The obtained errors are lesser than those of the original codes equations and the average errors are on the conservative side.

Punching Shear Strength Prediction for Reinforced Concrete Flat Slabs without Shear Reinforcement

“…The type of concrete also contributes to punching shear strength where the use of self-compacting concrete is found to enhance the capacity of flat slabs [21], and the use of high strength concrete led to a significant increase in punching shear capacity as compared to normal strength concrete [22]. Issa and Ismail [23], carried out a comparative study between the international building codes and collected experimental tests on punching strength. ACI-318-19 and Egyptian building codes don't take into consideration the flexural reinforcement effect on punching shear strength; however, they can provide a good correlation with the data from experiments.…”