Seismic upgrade with CFRP of RC columns containing lap-spliced rebars in plastic hinge regions.

摘要

Reinforced Concrete Columns detailed with poor lap splices and inadequate transverse confinement at the potential plastic hinge region near the footing or beam-column joint are found to be deficient under the strength and ductility demands imposed by severe earthquake. The current study is directed towards the evaluation of the effectiveness of Carbon FRP laminates in strengthening and repair of columns with poor splice and confinement details, under simulated earthquake loading.; A total of 12 columns were constructed and tested. The variables studied in this program included, effect of the presence of lap splices, the effectiveness of CFRP, as well as effects of level of axial load, shape of column cross-section and confinement details. The CFRP retrofitting technique was found to be effective in enhancing the seismic resistance of the columns and resulted in more stable hysteresis curves with lower stiffness and strength degradations as compared to the un-retrofitted columns.