Design equations for axially loaded reinforced concrete columns strengthened with fibre reinforced polymer wraps

Abstract

Step-by-step design procedures are proposed for the axial load capacity enhancement of circular and rectangular reinforced concrete columns confined with fibre reinforced polymer (FRP) wraps. The design methods are intended for practicing engineers in that they are relatively simple to apply and are made readily available in a design code format. Commentaries are presented to explain the design philosophy and rationale leading to the various design equations. For purposes of validation, numerical results based on the proposed design equations are compared against available experimental data. Strengthening limits, as governed by creep and fatigue phenomena, are also proposed. Whenever test data are found to be too limited, conservative approaches are adopted. Various experimental investigations are suggested for future work to further validate and update the design equations.Key words: FRP strengthening, concrete columns, axial loading, confinement, design.