Title:
Punching Shear Behavior of Slabs With Varying Span-Depth Ratios
Author(s):
John S. Lovrovich and David I. McLean
Publication:
Structural Journal
Volume:
87
Issue:
5
Appears on pages(s):
507-512
Keywords:
concrete slabs; punching shear reinforced concrete; reinforcing steels; shear properties; shear strength; span-depth ratio; Structural Research
DOI:
10.14359/2616
Date:
9/1/1990
Abstract:
Results of an experimental investigation of the punching shear strength of reinforced concrete slabs with varying span-depth ratios are summarized. Ten axisymmetric slabs were tested: five with flexural reinforcement and five with both flexural and shear reinforcement. The slab thickness was kept constant while the support diameter was varied to produce different span-depth ratios. The punching shear strength was found to significantly increase as the span-depth ratio decreased below 6. Maximum test strengths were nearly five times greater than the 1983 ACI Building Code predicted strengths. The higher strengths were a result of smaller span-depth ratios, in-plane compressive forces caused by restraining action at the supports, and excellent anchorage provided for the shear reinforcement.