||The performance of RC columns subjected to axial force is relative to the
confinement. CFRP wrapping, a generally adopted retrofit method, was proved
not to effectively provide confining force due to the bulging effect on the
column face. Therefore, this paper is focused on the performance of the
retrofitted full-scale rectangular RC columns using different retrofit schemes
including the proposed CFRP wrapping conjugated with FRP Anchors method.
A total of eleven rectangular RC columns with low transverse
reinforcement ratio were constructed. Among them, one was tested as
benchmark; one was purposely constructed with larger transverse reinforcement
ratio; five were retrofitted by using CFRP wrapping and FRP Anchors; and the
other four were retrofitted by using different shapes of steel jacketing alone or
with adhesive anchors. All the specimens were subjected to monotonic
incremental axial force until failure occurred.
Experimental results demonstrated that the ductility of the specimens
retrofitted by using CFRP wrapping with FRP Anchors was significantly
improved compared with those retrofitted by using only CFRP wrapping. On the
other hand, the specimen with octagonal steel jacketing performed better than all
other specimens not only on ductility but also on strength. Finally, a novel
numerical model considering the contribution of the retrofit material will be
proposed and validated in the future.