Presented by Elias Saqan, American University in Dubai; Hayder Rasheed, Kansas State University; and Tarek Alkhrdaji, Structural Technologies FRP strengthening has been established as the method of choice to strengthen concrete structures. ACI 440 committee has completed its seismic design and detailing guidelines pertaining to this application while ACI 369 committee is working on updating its standard for evaluating FRP strengthening performance in seismic regions. Due to the lack of enough experimental studies, the subject of FRP anchorage has not been addressed in quantifiable sense. This study is intended to examine the seismic performance of beam-column systems strengthened with CFRP and anchored using state of the art wrapping and spike anchors. The seismic response is traced cyclically up to 3% drift ratios in the column member. Five full scale RC assemblages were tested as a control, strengthened with full wraps, strengthened with two arrangements of spike anchors and strengthened with a combination of a spike anchor and full wrap. Various parameters have been extracted from the hysteresis response including equivalent stiffness degradation, peak-to-peak stiffness degradation, energy dissipation, equivalent damping ratio, and envelop curves. The dense spike anchor installation in the plastic hinge region along with the spike anchors coupled with full wrap were seen to yield the best seismic performance overall. The former anchorage arrangement is suggested to use when access is not available to provide full wrapping at the critical plastic hinge zone.
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