Hysteretic behavior of concrete cylinders confined by active confining SMA wire jackets

Abstract

Shape memory alloy (SMA) wire jackets are distinct from conventional jackets for concrete members since they can provide active confinement easily. The applications of SMAs in civil engineering are on the increase since SMAs show unique properties of shape memory effect and superelastic behavior. Especially, the seismic application of SMAs for confining concrete becomes a hot issues in recent. Thus, this study conducts cyclic compressive tests of concrete cylinders jacketed by shape memory alloy (SMA) wires which can provide active confinement due to shape memory effect. Monotonic compressive tests provide only the peak strength and the ultimate strain for confined concrete. However, confined concrete is exposed to the repeating of loading and unloading during an earthquake. Also, this study performs the same tests for concrete cylinders jacketed by steel jackets which provide only passive confinement and the results are compared to those of SMA wire jackets. This study provides the basic information of concrete behavior confined by active or passive external jackets. © (2010) Trans Tech Publications.