8. SMA Concrete Confinement: Column Applications

This chapter builds on the discussion that started in Chap. 7 on the application of concrete confinement using shape memory alloys (SMAs). Since columns play a critical role in structures, especially during extreme events like earthquakes, the chapter highlights several confinement applications in reinforced concrete (RC) circular and con-circular columns. SMA transverse reinforcement is placed internally for the newly constructed columns, while for the columns of existing structures that need retrofitting or repair, the SMA is placed externally. The chapter discusses the challenges facing conventional retrofitting of non-circular columns and how SMA confinement could help address this problem. It also highlights the efficacy of the new SMA confinement technique, whether used individually or as a supplement to other confinement techniques (e.g., fiber-reinforced polymer), in mitigating the damage sustained by the columns during strong earthquakes. The efficiency of using SMAs in performing emergency repair of severely damaged columns is demonstrated experimentally.