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 = 4Size of longitudinal bars = No. 10Size of ties = No. 4Concrete strength = 7,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

Ties serve as shear reinforcement for columns.

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.

Determine the maximum pitch, s, for the spirals in the following circular column.Column diameter, h = 26 in.Clear cover to spirals = 1.5 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 8Size of spiral = No. 3Concrete strength = 3,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of spiral = 60,000 psi

Determine the maximum pitch, s, for the spirals in the following circular column.Column diameter, h = 18 in.Clear cover to spirals = 1.5 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 10Size of spiral = No. 4Concrete strength = 8,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of spiral = 60,000 psi

Most compression members in concrete are only subjected to uniaxial loads.

The strain will be unequal in the steel and concrete that are bonded together in a symmetrical column subjected to a concentric axial load.

Determine the location of the neutral axis, c, for the following tied column when the largest strain in the concrete is 0.003 and the strain in the tension reinforcement is 0.003.b = 16 in.h = 24 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 9Size of ties = No. 3Concrete strength = 5,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

Determine the maximum axial strength φPn,max for the following tied column.Column width, b = 20 in.Column thickness, h = 28 in.Number of longitudinal bars = 14Size of longitudinal bars = No. 6Size of ties = No. 4Concrete strength = 3,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi

Columns with only two layers of steel and a low steel ratio typically have interaction diagrams composed of straight lines.