Strengthening of flexure-dominate RC columns with ECC jackets: Experiment and analysis

Abstract In order to investigate the practicability of manual trowelling engineered cementitious composites (ECC) jacket for seismic enhancing of flexure-dominate reinforced concrete (RC) columns with high axial load levels. Six identical non-engineered RC columns were prepared, including two control specimens, one ferrocement jacketed specimen and three ECC jacketed specimens. The effect of axial load levels and jacket schemes on the failure patterns, hysteresis curves, ductility indexes, and energy dissipation ability of the column specimens were studied by using pseudo-static tests, respectively. The results indicate that RC columns jacketed by ECC exhibited improved failure mode, hysteresis response, flexural strength, plastic deformation and energy dissipation. With larger axial compression ratio, the growth in plastic deformation was more significant as well as the energy dissipation, which demonstrates that the manual trowelling ECC jacket is an effective strengthening technique. Besides, an analytical model based on the plane section assumption is presented to calculate the flexural capacity of ECC strengthened columns, which was validated to be reasonable by the test results and relative research.