STRESS-STRAIN BEHAVIOR OF CONCRETE UNDER CYCLIC LOADING

A rational analysis of reinforced concrete (RC) structures requires sa tisfactory modeling of the behavior of concrete under general loading patterns. The behavioral characteristics of concrete dominantly depend s upon its load history. For the study of concrete behavior, parametri c study and experimental investigation into the behavior of concrete u nder load history of random cycles are performed. Through parametric s tudy, the applicability of the previous concrete models is examined an d a physically motivated modeling for the cyclic stress-strain relatio nships is proposed. The present modeling of concrete under general cyc lic lending is initiated to provide substantial applicability flexibil ity of mathematical expressions, and, furthermore, to describe the beh avior of random cycles. For the experimental study of concrete subject ed to cyclic axial compressions, tests of 3 in. by 6 in, concrete cyli nders are conducted under four different loading regimes to determine the major experimental parameters for the proposed analytical expressi ons. The model developed is based on the results of parametric study a nd experimental data obtained for the present study. The validity of t he proposed general cyclic model is confirmed through a comparison of the experimental results and simulated behavior of the model.