New method of strengthening reinforced concrete square columns by circularizing and wrapping with fiber-reinforced polymer or steel straps
MetadataShow full item record
This study investigates three methods of strengthening existing reinforced square concrete columns under different loading conditions. Four groups of sixteen reinforced concrete square columns were made from normal-strength concrete. Reinforcement was kept at minimum ratio, simulating columns that need retrofitting. Columns of the first group were reference columns (Group N), while the corners of the second group columns (Group RF) were rounded and wrapped with three layers of carbon-fiber-reinforced polymers (CFRPs). The sides of the columns of the third group (Group CF) were bonded with four pieces of concrete with a segmental circular shape, thus changing the cross section of the column from a square to a circle before each column was wrapped with three layers of CFRP. The columns of the last group (fourth) were modified as the third group to result in a circular cross section, but were confined with steel straps. Results from the study showed that all confinement methods increased the capacity and ductility of columns. In particular, segmental circular concrete covers dramatically reduced the stress concentration at the corners and increased confinement efficacy. The interaction (P-M) diagrams of experimental results and theoretical analysis all confirmed high performance of groups RF and CF.
Showing items related by title, author, creator and subject.
Lei, X.; Pham, Thong; Hadi, M. (2012)This study evaluates different methods of strengthening existing square concrete columns under eccentric loading. Sixteen reinforced square concrete columns were cast. The columns were made from normal strength concrete ...
Doan, L.; Lei, X.; Pham, Thong; Hadi, M. (2013)© 2013 International Institute for FRP in Construction. This study presents an experimental investigation into strain distribution of Fibre-Reinforced Polymer (FRP) in FRP-confined concrete columns with internal steel ...
Pham, Thong; Doan, L.; Hadi, M. (2013)A technique called circularization [where segmental, circular, concrete covers made of different concrete strengths (40 MPa, 80 MPa and 100 MPa)] was used to change a square column to a circular column. The behavior of ...