Upgrading reinforced concrete columns. Particular aspects that determine the design and execution

Abstract

The upgrading techniques of reinforced concrete columns conventionally have been jacketing or confinement of the existing column using concrete or steel. In recent years the use of composite materials, or fibre-reinforced plastic (FRP), has been incorporated as an alternative material in upgrading solutions by confinement. Although there is no problem in the dimensioning of any of these solutions, the resolution of details has often influenced its effectiveness. Thus, apparently simple aspects, such as transmission of the axial force to the upgrading system, must be carefully evaluated. Using particular examples, this article illustrates some reinforcements that have been overlooked by calling its validation into question.