Long-term response of concrete-encased composite columns

During the last few decades, owing to their several advantages, composite columns have gained acceptance for high-rise buildings as an alternative to steel or reinforced concrete columns. When a composite column is subjected to an eccentrically applied sustained axial load, its structural response must undergo both a short-term and long-term analysis. The study presented in the current paper aims to evaluate the short- and long-term response of concrete-encased composite columns. A numerical model previously developed and experimentally verified is systematically used within this work. This model is capable of developing non-linear and time-dependent analyses on reinforced concrete frame structures. In order to verify the obtained numerical results for this particular case, a series of experimental results on concrete-encased composite columns are compared with those derived numerically. Once verified, the model is used as a simulation tool to analyse in depth the structural short- and long-term response of composite columns. Finally, based on the present study, conclusions about design criteria for concrete-encased composite columns are drawn.