This research studies behavior of reinforcing steel subjected to cyclic loadings. Twenty-eight specimens were prepared from 25 mm. diameter deformed bars. The deformed bars were manufactured in accordance with TIS 24-2527. In order to investigate effects of yield strengths on the cyclic behavior of the specimens, two grades of steel (SD30 and SD40) were used in the study. The specimens were subjected to cyclic uniaxial loadings and different loading history was used for each specimen. The stress-strain relationship of the specimens was recorded and used as the database for material model evaluation and for parametric study. The Ramberg-Osgood model proposed by other researchers were used for modeling cyclic behavior of reinforcing steel in this study. The parameters of the model were adjusted so that a good correlation between the test results and the analytical results was obtained. The model and the adjusted parameters satisfactorily predict the cyclic stress-strain relationship of the test specimens.
