Axial Load Capacity Evaluation of High Strength CFT

고강도 콘크리트충전강관기둥의 축압축 내력평가

In recent years, many countries are continuing to construct the super tall buildings despite of the global economic crisis. In case of super tall buildings, increase in the load of vertical members increases the important issues. Many researchers conducted the research on the high strength concrete filled steel tube to resolve these problems. The purpose of this study is to investigate the ultimate axial load capacity on the high strength CFT to evaluate the suitability of design code and enlarge the limit of material's strength based on the test results of various variables. The main variables were concrete compressive strength(30~100 MPa) and yield strength of steel(235~723 MPa) on the short and long CFT columns. Total 14 CFT short and long column specimens were tested under the axial compression. Test results were analyzed in the viewpoint of axial load capacity, load-shortening relationship, and failure aspect. KBC 2016 code was used to evaluate the test results. The results of this study were as follows; KBC 2016 code can safely predict the load capacity of the CFT regardless of the section type of the element or the strength of steel. But in the case of using the high strength concrete, it has appeared to be less safe in accordance with the confinement effects. On the other hand, safety ratio of the high strength steel is higher than that of normal strength steel because of reflecting the effect of slenderness ratio.