Ultimate Punching Shear Strength Analysis of Slab-Column Connections With Steel Fibers

Abstract

A simple analytical model is presented to predict the ultimate punching shear strength of slab-column connections made with steel fiber concrete. The model is based on the physical behavior of the connection under load, and is therefore applicable to both lightweight and normal weight concrete as well as to concrete without fibers. The model assumes that punching is a form of shearing without concrete crushing, and occurs when the tensile splitting strength of the concrete is exceeded. The theory is applied to predict the ultimate punching shear strength of forty seven slab-column connections tested by the authors and other researchers over a period of several years and designed to fail in shear, involving a wide range of fiber variables, concrete strength, tension steel ratio and loaded area. The results show very good agreement between the predicted and experimental values. The uniqueness of the model is that it incorporates many physical characteristics of the slabs and their failure behavior.