Plane stress tension stiffening effects in reinforced concrete

Abstract

This paper presents a simple model for the prediction of the structural behaviour of reinforced concrete in plane stress. Stresses, strains and crack widths are determined. The model applies the well-known diagonal compression stress field of concrete, amplified to include a so-called developing crack phase, where tension stiffening effects may account for a significant part of the overall stiffness. In this respect, the major assumption of the theory is that the tension stiffening effects are expressible in terms of the mean crack width. A simple linear tensile softening response is assumed introducing a so-called critical crack width, which denotes the crack width level at which tension stiffening effects vanish. The model is compared with tests, and considering the recognised difficulties in the field, a rather good agreement is obtained.