Step-by-step processes for developing a column

Construction of a column

Vertical Reinforcement: A rectangular column should contain minimum 4 reinforcements at 4 corners.

Circular Column in Reinforcement: Circular column should contain at least 6 reinforcements.

The highest reinforcement should be 8% and lowest reinforcement should be 1%.

Overlapping of Rods: It is performed if the length of reinforcement bar is small but bigger reinforcement is essential.

Arranged in mid span
Affixed with hooks

Ties: Column contains closed lateral ties which are arranged equivalently over the column.

Withstand shear force and bursting out effect.
Bars having different types of diameters like 10 mm, 12 mm are applied.

Positioning of Ties:
Normal spacing = S in mid span
Gapping near support joint = S/2

Hooks: The objective of hooks is to withstand enlargement.
The hooks should have been curved at 135 degree.

Formwork: It should have resistance capacity against leak. It has smooth inside and it should be arranged perfectly.
Minimum clear cover in formwork should be 1.5.

Casting in Column: The casting in concrete is performed in two lifts. To get rid of concrete segregation, casting should not be performed from over 5 feet high.

Compaction & Removal of Formwork: Compaction is performed through vibrator.

To make superior bonding among new and old concrete, construction joints are utilized.
Elimination of formwork is done after 3 days.

Curing: In curing, water is arranged for hydration reaction.
Raise the strength up to 2.5 times.
Curing is accomplished for 21 days.
To make curing stronger, gunny bags are utilized.

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