Spirals are normally made from Grade-_____ steel.

To minimize splice lengths, choose the smallest practical bar size and the highest practical concrete strength.

For tied columns in seismic regions, ties are spaced roughly the width of the column apart.

A common example of a column supporting axial forces and bending about two perpendicular axes is a corner column in a frame.

Determine the maximum axial strength φPn,max for the following tied column.Column width, b = 24 in.Column thickness, h = 28 in.Number of longitudinal bars = 8Size of longitudinal bars = No. 8Size of ties = No. 3Concrete strength = 8,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

Tied columns cannot be circular-shaped.

Determine the maximum axial strength φPn,max for the following tied column.Column width, b = 26 in.Column thickness, h = 12 in.Number of longitudinal bars = 10Size of longitudinal bars = No. 6Size of ties = No. 4Concrete strength = 4,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

Because the designer has little control over the arrangement of the bars in a circular column, the interaction diagram should be computed for the least favorable bar orientation.

Columns with spirals generally exhibits more ductility than columns without spirals.

Determine the maximum axial strength φPn,max for the following tied column.Column width, b = 26 in.Column thickness, h = 14 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 7Size of ties = No. 3Concrete strength = 9,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi