S. Eshghi, V. Zanjanizadeh,
Volume 5, Issue 3 (September 2007)
Abstract
This paper presents an experimental study on seismic repair of damaged square reinforced
concrete columns with poor lap splices, 90-degree hooks and widely spaced transverse bars in
plastic hinge regions according to ACI detailing (pre.1971) and (318-02) using GFRP wraps. Three
specimens were tested in “as built” condition and retested after they were repaired by glass fiberreinforced
plastic sheets. They were tested under numerous reversed lateral cyclic loading with a
constant axial load ratio. FRP composite wraps were used for repairing of concrete columns in
critically stressed areas near the column footings. Physical and mechanical properties of composite
wraps are described. Seismic performance and ductility of the repaired columns in terms of the
hysteretic response are evaluated and compared with those of the original columns. The results
indicated that GFRP wraps can be an effective repair measure for poorly confined R/C columns
due to short splice length and widely spaced ties with 90-degree anchorage hooks. Both flexural
strength and ductility of repaired columns were improved by increasing the existing confinement in
critical regions of them.