Experimental Study on Column Strengthening Using Pre-tensioned Steel Straps Confinement

Earthquake excitation can exert combined flexural, axial, shear, and torsional loading on reinforced concrete (RC) columns. Although behaviour of confined columns under cyclic pure bending load has been extensively investigated, the research on interaction between bending and torsion in confined columns is still limited. The studies of active confinement on its effectiveness in enhancing the behaviour of RC column subjected to combined loading are also scarce. This paper presents experimental studies on two similar concrete columns. One of the columns served as control specimen, while the other one confined with steel straps. Both columns were tested under constant axial and cyclic lateral load including torsion. This paper aims to study the effectiveness of the steel straps in upgrading the performance of the columns. Load deformation curves, energy dissipation, column cross-section curvature, rebar and steel straps strain value are being compared and presented in this paper. From the result, steel straps tensioning technique (SSTT) managed to improve the performance of column and achieve the purpose of strengthening the column under cyclic lateral load.