Title:
Tangential Strain Theory for Punching Failure of Flat Slabs
Author(s):
Carl Erik Broms
Publication:
Structural Journal
Volume:
113
Issue:
1
Appears on pages(s):
95-104
Keywords:
flat slab; mechanical model; punching failure
DOI:
10.14359/51687942
Date:
1/1/2016
Abstract:
A novel mechanical model for the punching failure at interior columns of flat slabs without shear reinforcement is presented. It is based on fundamental structural mechanics and the stress-strain relation of compressed concrete. The shear force is assumed to be transferred to the column by an inclined circumferential compression strut that squeezes the concrete within the column perimeter, and when the compression stress in this area approaches the yield level, an increasing part of the squeezing pressure is anchored back to the surrounding concrete. Ultimately, the compression zone outside the column is assumed to collapse due to the generation of radial tension strain. Validation against test results in the literature demonstrates that the proposed model can accurately predict the punching capacity and the concurrent ultimate slab rotation. Both concentric and eccentric punching can therefore be analyzed.