Abstract
This paper presents an experimental study on the seismic retrofit of circular reinforced concrete bridge columns by carbon fiber sheets. Cyclic loading tests were conducted for six specimens; Two were tested under as-build condition and four were retrofitted by wrapping carbon fiber sheets horizontally to enhance ductility. It was found from the tests that stable flexural capacity range increased from about 3% drift to 5% drift by wrapping the carbon fiber sheets. The ductility factor of columns confined by carbon fiber sheets in two layers was smaller than that of columns confined by carbon fiber sheets in one layer. Flexural strength and ultimate displacement was evaluated using stress vs. strain relation of concrete confined by carbon fiber sheets.
