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

Compute the axial compressive strength Pn and moment capacity Mn of the following tied column when the largest strain in the concrete is 0.003 and the strain in the tension reinforcement is 0.003. Note that you should not include φ in the answer and that you should not consider Pn,max.b = 12 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 = 8,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 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

Determine the maximum axial strength φPn,max for the following circular tie column.Column diameter, h = 22 in.Number of longitudinal bars = 10Size of longitudinal bars = No. 6Size of ties = No. 4Concrete strength = 6,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi

The equation P/Pmax + M/Mmax = 1 is known as a/an _______ equation.

ACI 318-14 Section 25.7.3.1 limits the clear spacing of spirals in a column to a maximum of _______.

_______ columns are those which are not appreciably weakened by moments induced by slenderness effects.

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

What is the easiest way to analyze a column section?

Generally, columns are built with the same reinforcement in the two faces parallel to the axis of bending.