Behaviour of circular SMA-confined reinforced concrete columns subjected to eccentric loading. (15th July 2020)

• Record Type: Journal Article
• Authors: El-Hacha, Raafat; Abdelrahman, Khaled
• Is Part Of: Engineering structures. Volume 215(2020)
• Publication Date: 2020-07-15
• Subjects: Circular, confinement -- Carbon -- Ductility -- Fibre reinforced polymer -- Shape memory alloys -- Strength; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2020.110443
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Strength and deformability of the actively SMA-confined columns increased significanlty. The axial strength capacity of the CFRP and the SMA-confined columns were comparable. Ductility of the SMA-confined columns was improved significantly than the CFRP-confined columns. Abstract: Shape Memory Alloys (SMA) are recently utilized for strengthening/repair of concrete structures. Commonly used SMA wires used for concrete confinement applications are those in Nickel-Titanium ( NiTi ), because they possess unique thermo-mechanical properties such as shape memory effect (SME) along with high recovery stress (up to 600 MPa) and strain (up to 8%). Initial investigations reported in the literature show actively confining concrete columns with SMA wires can enhance the strength and the ductility of concrete. To date, vast majority of experiments on SMA-confined concrete have considered short, unreinforced, small-scale concrete cylinders subjected to concentric axial loading. The objective of this study is to present a systematic study of circular SMA-confined reinforced concrete (RC) columns subjected to eccentric loading. Test data are compared against identical unconfined RC columns, and RC columns confined passively using conventional CFRP sheets. The results of this study show the RC columns confined with active SMA spirals exhibited significant enhancement in strength and ductility compared to unconfined RC columns subjected to varying load eccentricity. Additionally, the SMA-confined RC columns demonstrated superior overall performance when compared to the conventional passive CFRP-confined RC columns.