Based on the ACI 209 method for predicting the creep and shrinkage of concrete,a study was conducted using age-adjusted effective modulus method to evaluate the deformation and stress redistribution of the long-term axially loaded concrete columns reinforced with concrete filled steel tube(CCRST),which was an ordinary reinforced-concrete column where there was a steel tube designed to be put in the core additionally.In addition,it was also examined the influence of different parameters,such as the age at first loading,the magnitude of loading and the area ratio of steel to gross section on the deformation and stress redistribution of the axially loaded CCRST columns.The analysis indicates that the deformation caused by the creep and shrinkage develops quickly in the early loading phase(within 4 or 5 months after loading),and the results of the stress redistribution will lead to a remarkable increase of the stress in steel tube.
Zhao Guofan, Zhang Dejun, Chen Zhouyi.Behavior and Design ofHigh-Performance Concrete Columns Under Cyclic Loading[C]//Proceedings of ICCMC /IBST 2001International Conference onAdvanced Technologies in Design, Construction and Maintenanceof Concrete Structures.2001:230-236.