Blog

For tied columns in seismic regions, ties are spaced roughly the width of the column apart.

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

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 = 24 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 6Size of longitudinal bars = No. 8Size of ties = No. 3Concrete strength = 5,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi

Determine the required splice length for the epoxy-coated longitudinal bars in the following tied column made of normal-weight concrete. Assume that some of the longitudinal bars are in tension and that the connection should be designed as a Class B contact lap splice. Use ACI 318-14 Table 25.4.2.2 to calculate the development length, and assume that the ties satisfy the Code minimum.Column width, b = 22 in.Column thickness, h = 24 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 12Size of longitudinal bars = No. 9Size of ties = No. 3Concrete strength = 3,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

The minimum number of bars in a _______ column is six.

Spiral reinforcement acts to restrain the lateral expansion of the column core under high axial loads and delays the failure of the core, making the column more ductile.

To minimize splice lengths, choose the smallest practical bar size and the lowest practical concrete strength.

Determine the required splice length for the uncoated longitudinal bars in the following tied column made of normal-weight concrete. Assume that some of the longitudinal bars are in tension and that the connection should be designed as a Class B contact lap splice. Use ACI 318-14 Table 25.4.2.2 to calculate the development length, and assume that the ties satisfy the Code minimum.Column width, b = 22 in.Column thickness, h = 26 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 4Size of longitudinal bars = No. 10Size of ties = No. 3Concrete strength = 3,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

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

Tied columns have higher ductility giving less warning before a failure.