The experimental program of this study
consisted of 12 slab specimens. The parameters
investigated include ratio of reinforcement in compression and tension, amount of shear reinforcement
and arrangement of shear reinforcement. Flexural
reinforcement ratio especially in tension had a
noticeable effect on the mode of failure and ultimate
punching capacity of slabs. The enhancement in the
ultimate loads due to increasing tensile reinforcement
ratio was ranging between 26.0 and 42.0%. Slightly
enhancement (up to 12%) in ultimate loads was
observed as a result of increasing compressive steel
ratio. Provision of shear reinforcement was shown to
be increased the perimeter of the failure. The ultimate
loads were increased with the addition of single leg
stirrups as shear reinforcement particularly in case of
radial arrangement of shear reinforcement. The ECCS
shows the most conservative prediction for punching
shear capacity specially in case of using shear
reinforcement and the mean predicted-to-experimental ultimate load is shown to be 0.7. The predictions
following the ACI and CSA are closet to the experimental results. The mean predicted-to-experimental
ultimate load is shown to be 0.8 for ACI and 0.96 for
CSA. The BS provisions for punching shear analysis
were shown to be overestimated in some cases, where the mean predicted-to-experimental ultimate load is
shown to be 1.19. |
