This study investigates the effectiveness of a new technique for seismic strengthening of substandard reinforcing details of exterior beam-column connections (T connections) using segmental circular concrete covers together with carbon fibre reinforced polymer (CFRP). Four reinforced concrete T connections without transverse reinforcement at the joints were cast and tested under cyclic loading. The first connection was tested as the control specimen. The remaining three connections were glued with concrete covers around the column at the joint area to modify them from square to circular sections and then they were wrapped with different ratios of CFRP. The test results showed that the variation of the CFRP ratios led to different failure modes of the examined connections. Despite the differences in the failure modes, the shear performance of the retrofitted specimens improved significantly. The modification of the column from square to circular sections not only helped in reducing the debonding possibility of the CFRP but also improving the confinement effect of the CFRP.