Yes
The current paper presents a simple unbonded-type column strengthening technique with wire rope units and few
steel elements. Eleven short columns were strengthened using the proposed procedure and tested under monotonic
concentric axial loads. The main variables investigated to evaluate the confinement effectiveness of strengthened
concrete columns were the volume ratio, prestress, diameter, spacing and configuration of wire rope units. The
strength gain factor and ductility ratio increased with the increase of volume ratio of wire ropes. The prestress
applied to wire ropes had little influence on the strength gain factor but the ductility ratio decreased with the
increase of prestress in the wire ropes, owing to earlier rupture of wire ropes. At the same volume ratio of wire
ropes, the maximum strength of columns was nearly independent on the configuration of the wire ropes, but higher
ductility was exhibited by columns strengthened with rectangular spiral-type wire ropes than by columns strengthened
with hoop-type wire ropes, until rupture of the wire ropes. The strength gain factor and ductility ratio of
strengthened columns were compared with those of tied columns tested in a previous study. The load capacity of
strengthened columns was also predicted using the ACI 318-05 equation modified to reflect the load-carrying effect
of steel elements. A much higher strength gain factor and ductility ratio were exhibited by strengthened columns
than tied columns having the same lateral reinforcement, except for strengthened columns with wire rope spacing
above 0.5 times core width. The axial load capacity of strengthened columns was higher than that of unstrengthened
columns by 5¿20%, and could be reasonably predicted using the modified ACI 318-05 equation.