**5. Conclusions**

In this study, an experiment was conducted to evaluate the flexural performance of RC columns confined with a newly developed spiral type transverse reinforcement (KSS). Experimental results were compared with an RC column confined with a conventional hoop reinforcement. The experimental results showed that KSS transverse reinforcement, due to its superior confinement effect for concrete and longitudinal reinforcement, increases the effective stiffness of columns at yield and maximum strength. Moreover, the results showed that the ductility and energy dissipation capacities of RC columns with KSS were improved compared with those of an RC column with conventional hoops, even though the amount of reinforcement used decreased by about 27%. Finally, it was found that KSS is effective at reducing the amounts of steel and time required to arrange transverse reinforcement.

**Author Contributions:** Investigation, D.-H.K.; Supervision, K.-H.K.; Writing—original draft, H.-G.K.; Writing—review & editing, C.-Y.J. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF) founded by the Ministry of Education (2019R1A6A1A03032988); This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) founded by the Ministry of Education (2018R1A2B3001656); This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) founded by the Ministry of Education (2019R1I1A3A01058156); This work was also supported by a research gran<sup>t</sup> of the Kongju National University in 2020 (2020-0203-01).

**Conflicts of Interest:** The authors declare no conflict of interest.
