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If additional steel reinforcement in a column prevents concrete from expanding outward under compression, then logically it follows that _______.

Over _____ percent of all columns in buildings in nonseismic regions are tied columns.

In tall buildings, the concrete strength in the columns is often selected to be _______ that in the floors.

Ties confine the concrete core and decrease the column’s ductility.

Spiral reinforcement acts to restrain the _______ of the column core under high axial loads.

In tall buildings, concrete strength in the columns is often higher than that in the floors.

What is the strength-reduction factor, φ, for tied columns?

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

Determine the maximum axial strength φPn,max for the following tied column.Column width, b = 24 in.Column thickness, h = 12 in.Number of longitudinal bars = 14Size of longitudinal bars = No. 8Size of ties = No. 3Concrete strength = 2,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

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 = 16 in.h = 20 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 8Size of ties = No. 4Concrete strength = 4,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi