Analytical Load Displacement Curves of RC Columns under Constant Axial and Cyclic Lateral Loads

Abstract

The cyclic tests of the columns are of practical relevance to the performance of compressionmembers during earthquake loading. The strength, ductility and energy absorption capabilities of RCcolumns, subjected to cyclic loading, have been estimated by many researchers. These characteristicsare not normally inherent in plain concrete but can be achieved by effectively confining columnsthrough transverse reinforcement. An extensive experimental program, in which performance of fourRC columns detailed according to provisions of ACI-318-08, was studied in comparisonwith that offour columns confined by a new proposed technique. Out of total eight, this paper presentsperformance of three columns which were detailed according to provision of ACI-318-08 and castwith 25 and 32 MPa concrete. The experimentally achieved load-displacement hysteresis andbackbone curves of the three columns are presented. Two approaches, which utilize moment-curvatureand shear-shear strain relationship of RC columns achieved through Response-2000, have beensuggested to draw analytical load-displacement curves of the columns. The experimental andanalytical load-displacement curves are found in good agreement. The suggested analytical techniqueis simple and easy to implement. The technique will be available to the engineers involved in design toestimate capacity of RC columns.