A large number of column-beam joints(C-BJ) have been damaged in the Wenchun earthquake. Thereby a proper method is urgently needed for strengthening the damaged joints. This paper presented the experimental study on the seismic behaviors of 4 repaired C-BJs, 2 of which had been pre-damaged under cyclic loads. The test procedure included pre-damage, rehabilitation and re test under cyclic loads. The test results showed that the failure mode of strong beam and weak column changed into strong column and weak beam after rehabilitations. The analysis of the hysteresis curves, ductility, and skeleton curves showed that the method of enveloped steel has significant improvements in both the stiffness and all aspects of seismic performance. The study indicated that the repaired C-BJs can reach or even exceed the level of their original seismic performance before pre-damage.
