Reinforced concrete is not elastic and has a compressive strength that is much higher than its tensile strength.

Determine the maximum axial strength φPn,max for the following tied column.Column width, b = 22 in.Column thickness, h = 26 in.Number of longitudinal bars = 12Size of longitudinal bars = No. 10Size of ties = No. 4Concrete strength = 7,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi

The minimum number of longitudinal bars in a rectangular column is four.

Determine the maximum pitch, s, for the spirals in the following circular column.Column diameter, h = 22 in.Clear cover to spirals = 1.5 in.Number of longitudinal bars = 16Size of longitudinal bars = No. 8Size of spiral = No. 4Concrete strength = 5,500 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 = 5,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of spiral = 60,000 psi

When designing columns, it is often more desirable to use symmetrical reinforcement.

Use the interaction diagrams found in Appendix A of the textbook to determine whether the following rectangular tied column with bars in 2 faces can safely support a load of Pu = 1,320 kip and Mu = 645.3 kip-ft.b = 20 in.h = 22 in.fc’ = 4 ksify = 60 ksiγ = 0.6ρg = 0.03

Use the interaction diagrams found in Appendix A of the textbook to determine whether the following circular spiral column can safely support a load of Pu = 704 kip and Mu = 160.8 kip-ft.h = 16 in.fc’ = 4 ksify = 60 ksiγ = 0.9ρg = 0.04

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 = 12Size of longitudinal bars = No. 6Size of spiral = No. 4Concrete strength = 3,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of spiral = 60,000 psi

To account for the effect of accidental moments, the maximum load on a tied column must not exceed 85% of the load capacity.