Simulated seismic load tests on reinforced concrete one-way interior beam-column joints with substandard reinforcing details typical of lowrise buildings constructed in Taiwan are described. These substandard reinforcing details of the beam-column joints are mainly lower concrete strength and lack of transverse reinforcement. RC jacketing offers a versatility for retrofitting those deficient buildings. The improvement in performance of the joints rehabilitated with RC jacketing, without dowel anchors into the concrete-to-concrete interface for preventing premature bond failure, is demonstrated. The experimental investigation toward the effect of the interfacial bond slip is discussed in the paper. Results showed the slip observed in newly casting concrete joint is unlikely to influence the overall seismic performance of the jacketed sub-assemblages if being strengthened to ensure the strong-column and weak-beam mode.