Moment-Curvature Relation of Reinforced Concrete Slabs

An analytical method is presented to derive the moment-curvature relationship for a slab element orthotropically reinforced with top or bottom steel, or both, and subjected to bending moment in two directions as well as twisting. The relationships considered cover the whole range of loading up to ultimate strength and is intended for use in conjunction with computer methods of analysis. The method takes into account the orientation of reinforcement with respect to the principal moment directions. It can be used with the actual nonlinear stress-strain relationship for the concrete and the steel. Thus, the effect of steel strain hardening is included. The stiffening effect of the tensile stress resisted by the concrete between the cracks is also presented. The procedure is verified by comparison with published experimental results. The method developed is applied to study the effect of varying several parameters affecting reinforced concrete slab behavior.