Investigation of design specification calculations for concrete filled steel tube columns

Steel and concrete are frequently used materials in civil engineering structures. While the concrete members benefit from high compressive strength and stiffness, the steel members possess benefits of high tensile strength and ductility. For this reason, composite member combines both steel and concrete to produce a member with beneficial properties for both materials. The (CFST) column is the most common kind of composite column. Using of CFST columns is becoming an important solution in construction due to their advantage especially under the loads of seismic. The concrete is confined by the steel, and this will offer under compression a highly ductile reaction. The presence of infill concrete improves the local buckling of steel tube. Circular CFST column have advantages in comparing with other sections, where provides much more confinement to the concrete because of the improvement in the composite actions between concrete and steel. Depending on the material and geometrical properties, capacity calculations of the design specification lead to discrepancies. To project the differences between the most popular design specifications a computational study is done by employing AISC 360 – 10, the Eurocode 4, AS 5100.6, and AIJ 2001. This study goals to investigate the differences between these design codes for circular CFST columns under axial load and to evaluate how they model the real column behavior through a series of statistical comparisons. Also, the parameters which are used in design specification calculations steps are assesse d. Keywords: CFST column, compression capacity, design specifications, experiments.