The Effect of Pre-Damaged Level on Repair Damaged Columns by Using Steel Straps Tensioning Technique

Abstract

To date, repair of damaged columns has become increasingly more significant. The failure of columns structure contributes to the serious consequences in structural stability. Most of the existing repairing techniques are based on lateral passive confining pressure. However, this passive-type of confinement is ineffective in restoring the performance of damaged concrete columns. In this regards, active confinement was selected in this study to repair damaged concrete columns which can actively confine concrete in this study. Steel strapping tensioning technique (SSTT) allows pre-tensioning low-cost recycled steel straps around the damaged column was chosen herein to represent active confinement. A total of 12 columns were prepared and loaded axially to certain degree of their respective ultimate strength. Hence, a pre-damage level of the columns was developed. Then, the damaged columns repaired by using mortar and confined with SSTT. Finally, the repaired columns were then tested under monotonic uniaxial load. The structural performances of the confined repaired columns were compared with those of the repaired columns without confinement. It is expected that as the concrete compressive strength increases, the effectiveness in restoring the load carrying capacity of the damaged column becomes more significant.

Corrosion effects on axial compressive behavior of steel strapping tensioning technique-confined concrete

“…where, ke is confinement effectiveness ratio for spacing determined by Eq (7); and ks is confinement effectiveness ratio for shape determined by Eq (8).…”

“…Chin et al [4] reported that with application of SSTT, the confined concrete able to achieve ductile post-peak behavior. It was also proven that SSTT able to rehabilitate damaged concrete structures, returning to its original strength [5][6][7]. Mohd Apandi et al [7] proven the ability of SSTT to rehabilitate the strength and ductility of damaged concrete structure, delaying its damage by increasing the ultimate strain.…”

“…It was also proven that SSTT able to rehabilitate damaged concrete structures, returning to its original strength [5][6][7]. Mohd Apandi et al [7] proven the ability of SSTT to rehabilitate the strength and ductility of damaged concrete structure, delaying its damage by increasing the ultimate strain. Nevertheless, SSTT also possess the advantage of flexibility in design [8].…”