Abstract: “Slenderness is an important factor in the design of long reinforced concrete (RC) columns. It is also a major problem for RC columns which are restricted to lateral displacement. In that case, buckling is effective on the second the second order effects. The elastic curve of the columns may have single or double curvature. The type of curvature is effective on slenderness of the column. In ACI318-Building code requirements for structural concrete-, an effect of slenderness is considered by using a moment magnification factor. In this factor, the type of curvature is also considered by a correction factor (Cm) which is defined according to end moments. For that reason, different flexural moment cases are presented in the present study. By employing teaching learning based optimization, the cost optimization of the columns was done. According to the results, the type of curvature is effective on the optimum design and cos”

Keywords: Reinforced concrete, slenderness, columns, optimization, metaheuristic methods, teaching learning based optimization