Strengthening of historic reinforced concrete columns using concrete and FRP jacketing techniques

The study of concrete structure strengthening utilizing various ways has recently piqued the interest of researchers. The researchers concluded that strengthening structural concrete parts such as reinforced concrete (RC) columns with a concrete and Fiber-Reinforced Polymer (FRP) jacket can result in a significant increase in the maximum failure load. The aim of this analysis was to evaluate and test the effectiveness of using concrete and FRB as a reinforcing material to reinforce the entire height of downscaled historic RC columns. One identical Group (G1) unstrengthen reference column (C1) with cross sections of 200 × 200 mm and a height of 1500 mm was used in the experiments. In addition, seven monolithically cast columns with identical cross sections of 200 × 200 mm and a height of 1500 mm were fabricated. All the columns were composed of weak concrete. In this paper, the applied strengthened styles were Group (G2), which consisted of four columns cores reinforced by entirely concrete, CFRP, GFRP, and BFRP jackets, and Group3 (G3), which consisted of three columns reinforced by partial striped FRP as a strengthening material. The failure load, failure pattern, and longitudinal axial strain of all produced column specimens were studied in this work by testing them under monotonic uniaxial compression stress. The G1, G2, and G3 specimens provided a significant considerable improvement in ultimate load failure load after strengthening by nearly 1.8 times than the reference column, according to the testing data. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.