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ACI 318-14 Section 25.7.2.1 specifies that ties shall have a center-to-center spacing of at least (3/4)dagg.

Spiral columns are often used in situations where ductility is important.

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 = 12 in.h = 22 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 9Size of ties = No. 4Concrete strength = 2,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi

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

Ties serve as shear reinforcement for columns.

In a tied column in a nonseismic region, the ties are spaced approximately the width of the column apart.

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 = 20 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 9Size of ties = No. 3Concrete strength = 3,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi

To reduce the chance of field errors, all of the bars in a column should have splices of the same length, regardless of whether they are on the tension or compression face.

Almost universally, an even number of bars is used in rectangular columns, so that the column is symmetrical about the axis of bending.

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