ABSTRACT
Concrete columns are divided into four categories. They are pedestals, columns with axial loads, short columns with combined loads, large or slender columns with combined loads. Composite columns are reinforced by steel shapes that are contained within the concrete sections or by concrete being filled in within the steel section or tubing. Axially loaded columns include columns with a small eccentricity. The analysis of columns of small eccentricity involves determining the maximum design load capacity and verifying the amount and details of the reinforcement according to the code. Design involves fixing the column dimensions, selecting reinforcement, and deciding the size and spacing of ties and spirals. The rigidity of the connection between beam and column makes the column rotate with the beam, resulting in a moment at the end. Even an interior column of equally spanned beams receives unequal loads due to variations in the applied loads, producing a moment on the column.
