The results of laboratory tests on four isolated and simplified reinfo
rced concrete beam-column joints, carrying quasi-static, cyclic, horiz
ontal loadings, are presented. The specimens were subjected to control
led deterioration in the first stage. Subsequently, they were thin ste
el-plate enveloped, sealed, and epoxy injected. The epoxy was used to
fill concrete cracks, to restore bond between reinforcement and deteri
orated surrounding concrete, and to glue the steel plates, which are u
sed as external reinforcement instead of the lost or damaged full rein
forcement. Two types of steel plates represented two-and three-dimensi
onal joint repair. Eventually, the repaired specimens were retested un
der similar loadings in the second stage. Comparison between the respo
nse of the specimens before and after repair clearly indicates conside
rable increase in initial stiffness, general yield resistance, envelop
e stiffness, and ultimate resistance with energy-dissipation capacity.
The repair technique was found to be efficient for mass repair or upg
rading of structures not suitably designed to withstand earthquakes.