Passive confinement of reinforced concrete members revisited

Abstract

AbstractPassive confinement provided by transverse reinforcement is taken into account in the design of reinforced concrete structures subjected to high compressive loading such as columns, piers, or tunnel lining segments. In current guidelines, several models exist to account for this beneficial effect. However, these approaches lack mechanical consistency regarding the three‐dimensional load dispersion of the confining forces. The article addresses this knowledge gap by introducing a new model based on a lower‐bound solution according to the theory of plasticity, along with a simplification regarding the governing confined concrete area. The proposed model and its simplified version are compared to the design approaches proposed by current guidelines, and both are successfully validated against experimental data. The simplified new model is a valuable alternative to existing models in current guidelines, as (i) it is mechanically more consistent, (ii) its application is more straightforward, and (iii) it allows the comprehensive treatment of rectangular and circular cross‐sections using the same equations.