Strength, ductility, and energy dissipation capacity of RC column strengthened with CFRP strip under axial load

Abstract

The experimental study aims to increase the axial load capacities of reinforced concrete (RC) columns with square cross-section by carbon fiber textile composite (CFRP) strips. The main purpose of the study is to develop a strengthening method that does not adversely affect displacement ductility ratios and energy dissipation capacities. Improved strengthening details have been applied to a square cross-section RC column with low axial load capacity, the low compressive strength of concrete, and the inadequate number of stirrups, which are not designed according to regulations. The main variables examined in this study are the CFRP strip width, the spacing of CFRP strips, the use of anchorage in the overlap zone at CFRP strips, and the placement of CFRP strips horizontally or vertically to the column axis. In line with this study, eleven reinforced concrete columns with dimensions of 150x150x500 mm were produced. The ultimate axial load capacity, initial stiffness, displacement ductility ratios, and energy dissipation capacities of the test specimens were evaluated. It was investigated how the variables in the experiments affected the behavior of the columns. The performances of the details developed for strengthening have been examined and interpreted.

Keywords:

• Reinforced concrete column
• CFRP
• strengthening
• axial load
• CFRP Fan type anchor