Type of column in construction

 


column:  When  vertical load carry and slab and beam dead load and live load transfer to footing that is called column .

 Column may be classified into the following two types, depending on whether slendeness effects  are considered insignificant or significant 

1.       Short column

2.        Long column

       The road of effective column length to least lateral dimension is referred to as ‘slenderness ratio’

  • Columns with slenderness ratio between 3 to 12 are short column which invariably fail under ultimate loads with the material reaching its ultimate strength and not by buckling
  • Column with slenderness ratio between 12 to 60 are long columns.
  • Column having slenderness ratio less than 3 are called as pedestal.


Maximum longitudinal reinforcement in an axially loaded column is 6% of gross cross sectional area and minimum is 0.8% of gross cross sectional area.

Columns with circular sections are mostly provided with transverse helical reinforcement, although they may be provided with circular stirrups as a transverse reinforcement but always helical reinforcement is preferred.

Spacing of lateral cannot be more than

  •     16 times the smallest diameter of longitudinal reinforcement bar to be tied.
  •     The least lateral dimensio  is 300mm.

Longitudinal reinforcement bars should be in contact with transverse reinforcement so that lateral confining of longitudinal bars occurs which will prevent buckling of longitudinal bars and increases strength of column.

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