Review of Shape Memory Alloys applications in civil structures, and analysis for its potential as reinforcement in concrete flexural members

Abstract

This paper synthesizes information on the properties of Shape Memory Alloys (SMAs) and its useful aspect towards utilization in civil engineering structures. A basic description of their highly non-linear material behavior in terms of shape memory effect, superelasticity, martensite damping and variable stiffness is presented in this article. The load-deflection behaviors of SMA reinforced concrete (RC) beams have been analyzed using prediction model codes. The effects of the cross-sectional area, reinforcement ratio, yield strength of rebar, and span of beams were considered. Effective moment of inertia, cracking moment, instantaneous and long-term deflections under variable load on beams were analyzed using ACI 318 (2005), Eurocode 2 (CEN 2002), AS 3600 (2001) and CEB (1993) codes. Deflections of SMA reinforced beams were compared with deflections of similar beams reinforced with conventional steel to present the potential of SMAs in restricting instantaneous & long-term deflections. Finally, a new scope of experimental research work is proposed utilizing SMAs as reinforcement in RC flexural members to minimize instantaneous & long-term deflections.