Display omitted •1-1/2 story substructures can better simulate seismic responses of the prototype.•Seismic behaviors of rehabilitated frames with exterior cantilevers were evaluated.•The validity of various retrofit strategies was verified and compared.•The seismic characteristics of a strengthened frame was enhanced substantially. Due to inadequate lateral stiffness and insufficient structural redundancy, many single-span reinforced concrete (RC) frames were highly damaged or collapsed in previous earthquakes. This paper presents an experimental study on seismic performance of rehabilitated single-span RC frames. Four frames were strengthened using various retrofitting strategies and one non-retrofitted frame served as the reference specimen. All these frames were fabricated and tested under cyclic loadings. The failure modes, hysteretic behavior, skeleton curve, energy dissipation, strength and stiffness degradation of each frame were evaluated. The validity of different strengthening methods for improving frames’ failure mechanisms and seismic performances was verified. Test results indicated that strength, stiffness, as well as many seismic characteristics of the strengthened frames were improved substantially.