Results of laboratory tests on four repaired reinforced-concrete flat-
slab interior column connections, carrying quasi-static, reversed, hor
izontal loadings are presented. The specimens, which originally had to
tally failed, were repaired and subjected to gradually increasing reve
rsed loading histories, similar to those imposed on the original speci
mens. A comparative analysis was made before the repair. The specimens
were repaired by using externally screwed steel plates replacing the
lost or damaged full reinforcement of the slab, In addition, high-pres
sure epoxy injection provided the bond between the concrete and the ne
w reinforcement. Moreover, this repair method can be easily used to re
store, strengthen, or upgrade existing and old flat-slab buildings, no
t suitably designed to withstand earthquakes, The practical aspects of
the repair technique developed for postearthquake mass production wer
e emphasized, with satisfactory results even when not applied by resea
rch laboratory experts.