Evaluation of Deformation Limits in Codes for Reinforced Concrete Columns

Abstract

Predicting the deformation capacities of reinforced concrete columns is necessary for seismic evaluation of existing and newbuildings. These deformation capacities have been set in terms of the rotation angle in EC-8 (2005) and ASCE/SEI 41 (2013)and strain in Turkish Seismic Code (2007-2016). In this study, finite element models of sixty-nine experimentally testedcolumn specimens were modelled and analyzed by using nonlinear finite element method. As a result of the analyzes, data,which is difficult to measure in experiments such as the strain of outer fiber of confined concrete, were calculated andcompared with code deformation limits. As a result of this study, EC-8 column ultimate deformation limits found to remainunsafe according to calculated deformation capacities herein. Taking into account TSC and ASCE/SEI 41, calculatedcapacities are in the safe region. However, for the axial load ratios over 0.45 and columns produced of high strength concrete,code limit state expressions are unable to predict the limit values correctly. In addition, TSC may significantly limit thedeformation capacity of RC columns under their actual capacities. There is a need to improve these code limits using a moreextensive column database which includes different design parameters.