Design-oriented method for the load-bearing capacity of RC columns jacketed by octagonal and spiral stirrups under axial and eccentric compression

The purpose of this study was to develop the design-oriented calculation method for the load-bearing capacity of RC columns jacketed by octagonal and spiral stirrups under axial and eccentric compression load. Based on the result of sixteen full-scale jacketed concrete columns which subjected to axial compression load, the judging method for the axial load-bearing capacity ultimate state of jacketed RC columns was determined. Then the design-oriented method for the axial load-bearing capacity of jacketed columns was proposed according to the axial load-bearing capacity ultimate state of jacketed RC columns. In addition, based on the six full-scale jacketed concrete columns which subjected to lateral cyclic load, the design-oriented calculation model for the relative compression zone height of jacketed RC columns under eccentric compression was proposed. And the calculation methods for evaluating the load-bearing capacity of jacketed RC columns with large eccentricity and small eccentricity were proposed, respectively. Furthermore, the predicted results from proposed method fitted well with the test results, which indicated that the proposed design-oriented methods were suitable for evaluating the load-bearing capacity of jacketed RC columns under axial and eccentric compression.