Column Design as per ACI codes

As per ACI Code 2.2:

A structural component having a ratio of height to least lateral dimension greater than 3
Hold up vertical loads shift those loads toward the footings.
Generally support compressive loads with or with no bending

Sorts of Columns – categorized into 3 sorts in accordance with reinforcement.

Tied Columns:

The longitudinal reinforcement bars are attached collectively with individual small diameter ties distanced at certain space beside the column height.
Those ties assist to keep the longitudinal reinforcement bars in position at the time of construction as well as assure firmness of those bars in opposition to local buckling.
Moreover, the cross sections of the columns are generally rectangular, circular, or square in form.
Nothing less than 4 bars are utilized in circular as well as rectangular cross sections.

Spirally-Reinforced Columns:

The longitudinal bars are set in a circle encompassed by a slightly distanced constant spiral.
Those columns are generally square or circular in form.
At the very least 6 bars is utilized for longitudinal reinforcement.

Composite Columns:

A column composed of structural steel pipes or forms enclosed by or loaded by concrete having or with no longitudinal reinforcement.

Inadequacy of Spiral and Tied Column:

Axial loading at spirally as well as tied reinforced columns with the similar cross sectional areas of concrete as well as steel reinforcement act in the similar way up till the ultimate load.
Moreover, on this load tied columns stop working abruptly because of major fissuring within the concrete segment succeeded by deforming of the longitudinal reinforcement amid ties in the collapse region.
With regard to spirally reinforced columns, at the time that ultimate load is attained, the concrete shell comprising the spiral begins to flake off/peel off. Merely afterwards, the spiral gets in on the act through offering a restraining/confining force toward the concrete core, therefore allowing the column to uphold significant distortions prior to last collapse happens.

ACI Code Requisites with regard to Columns – With regard to Ties Column:

No. 3 ties with regard to longitudinal reinforcement no. 10 bars or lesser, no. 4 ties with regard to no. 11 bars or bigger as well as bundled bars.
Tie distancing must not go beyond sixteen diameter of longitudinal bars, forty eight diameters of tie bars, also not the minimum dimension of column.
Each corner bar as well as alternate bars must have lateral tie offer the angle must not go beyond one hundred thirty five degree.
Moreover, no longitudinal bar must be distant greater than six inches devoid of a lateral tie.

To get more details, watch the following video.

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