FRP repair of damaged large-scale circular reinforced concrete columns – CICE 2012

Proceedings of CICE 2012 6th International Conference on FRP Composites in Civil Engineering - Rome, Italy, 13-15 June 2012

Very little research is available on the repair of damaged columns that were previously subject to realistic earthquake load histories. This paper presents the design philosophy developed as well as the experimental results of 2 large-scale columns, 600 mm in diameter and 2.4 m tall that were previously damaged, repaired using CFRP alternatives, and then subjected to reversed-cyclic loading. The overall objective of this research program is to demonstrate the ability to restore the lost strength and displacement capacity of damaged columns by means of FRP repair. To-date, two different FRP repair alternatives were executed, utilizing unidirectional carbon fiber sheets in the hoop and longitudinal directions; the latter anchored into the RC footing with 30 mm diameter carbon fiber anchors. Force-displacement responses from the tests were compared to a 3 cycle set “aftershock” test, which was performed on a column that had been subjected to an earthquake load history and not repaired afterwards. The responses show that FRP repair systems can restore the lost strength and displacement capacity of damaged RC columns.

Keywords: carbon fiber anchors, reversed-cyclic loading, FRP repair, damaged RC columns, earthquake load history