Presented By: Enrique del Rey Castillo, University of Auckland

Description: Existing reinforced concrete structures are frequently prone to severe damage and/or collapse as a result of the loads that the structure is expected to experience if it were to be subjected to large intensity earthquake shaking. ACI 440.2R 2017 recognizes using externally bonded fiber reinforced polymer (EBR-FRP) systems in combination with FRP anchors as one of the valid methods for seismic strengthening, but ACI 440.2R does not provide design guidance, other than broad statements and basic engineering judgment (e.g. ?Mn = Mu). A design method was proposed following several experiments, resulting in the moment capacity of the FRP strengthened columns being accurately calculated, although the deformation capacity could not be calculated using standard models and theories. A new tri-linear behavior model is proposed, and additional insight on the influence of the tension-compression cyclic loading, transverse reinforcement, using a bond breaking layer or quality of installation is included.