Investigation and Comparison of Circular Columns Strengthened with Steel Jacketing and FRP

Columns, as the main compressive members in structures, play a vital role in transferring vertical and lateral loads to the foundation. Given the importance of strengthening existing structures, selecting the optimal method for strengthening concrete columns is considered a key issue. This review study aims to investigate and compare the performance of circular columns strengthened with two methods: steel jacketing and FRP. The main objective was to quantitatively evaluate the advantages and limitations of each method based on technical and economic criteria. The present study was conducted through a systematic review of previous research on strengthening circular columns. The parameters examined included load-bearing capacity, ductility, failure patterns, stiffness changes, and the effect of geometric parameters. Quantitative data from various experiments were comparatively analyzed. Findings indicate that both methods created significant increases in load-bearing capacity (۱.۱۵ to ۲.۰۷ times). Steel jacketing provided the highest capacity increase (۷۵-۱۰۷%) due to composite action, while CFRP provided remarkable improvement in ductility (۵۹.۲-۹۵.۷%). Different failure patterns were observed: fiber rupture in FRP vs. steel buckling in jacketing. Increasing FRP thickness to ۹mm resulted in ۴۲.۵۸% displacement reduction and ۲۷.۳% compressive strength increase. Steel jacketing showed over ۱۰۰% increase in elastic stiffness and up to ۳۰% strength increase. Optimal method selection depends on design objectives: steel jacketing for load-bearing capacity increase and FRP for ductility improvement. Both methods are capable of ۵۲.۴-۹۹.۶% load-bearing capacity increase and restoring damaged specimens to service cycle.

کلیدواژه ها:

Concrete column strengthening ، Steel jacketing ، FRP composites