Strengthening of axially loaded circular columns

The application of a deformation-based analytical approach is presented in this paper to calculate the strength-increase of axially loaded circular columns, strengthened with fiber reinforced polymer and reinforced concrete jackets. A short introduction of the calculation methodology is presented and the adopted basic assumptions are briefly explained. Through a trial-and-error type iterative procedure the magnitude of confining stresses and the confined strength of core material are determined, based on the compatibility of lateral deformations of the core column and the jacket-wall. The accuracy of the proposed model for circular sections is demonstrated with a comparison with 149 test results