Confinement Reinforcement Design for Reinforced Concrete Columns

This paper presents new equations for the design of confinement reinforcement for ductile earthquake-resistant rectangular and circular columns based on performance measured in terms of curvature demand. These equations are developed from a parametric study of a large number of columns to reach a certain level of sectional ductility and account for the influence of concrete strength, transverse reinforcement yield strength, axial load level, and transverse confinement reinforcement spatial distribution. Simplification of these equations, while retaining the main controlling parameters, leads to design equations appropriate for design codes. These equations are then validated against a large set of experimental results. Their implementation in the Canadian Standard for Design of Concrete Structures is explained.