Different Types of Columns

Types of Columns Based on Shape

Columns can be divided into different types based on the shape of their cross-section. In this category, the most common types of columns are square/rectangular, circular columns, L-type columns, T-type columns and Y-type columns. These are further explained below.

Square/Rectangular columns- These are generally used in building constructions. Due to the ease of shuttering and reinforcement placement, these types of columns are both cost-effective and simple to construct.
Circular columns- Circular columns are commonly used in piling and elevation of buildings. It is also used as bridge pillars. They provide better bending resistance than square or rectangular column
L-type columns- These types of columns are commonly used at the corners of boundary walls.
T-type columns- These types of columns are quite commonly used in bridge construction.
Y-type columns- They are used in bridge and flyover construction.

Types of Columns Based on the Type of Reinforcement

Columns can be classified based on the type of reinforcement used in their construction. In this classification, we have 3 types of columns: tied columns, spiral columns and composite columns. These are further explained below.

Tied Columns- These are the types of columns in which the main longitudinal bars are enclosed within closely and uniformly spaced lateral ties. These are the most commonly used types of reinforced columns.
Spiral Columns- In these types of columns, the main longitudinal bars are confined within continuously wound spiral reinforcement. The spiral reinforcements provide lateral support and delay failure due to axial load.
Composite Columns- These are the types of columns where the reinforcement is in the form of structural steel sections or pipes with or without longitudinal bars.

Types of Columns Based on the Type of Loading

Columns can also be categorized based on how the load is acting on the cross-section of the columns. Different types of columns are defined based on whether the load is concentric or eccentric and if eccentricity is present, is it uniaxial or biaxial? Based on the above criteria, different types of columns are specified below.

Columns with axial loading (applied concentrically)- Axially loaded columns are the types of columns which has vertical axial loads acting on the centre of gravity of the cross-section of the column. These types of columns are not generally used in construction due to impracticality in coinciding vertical loads acting at the column’s centre of gravity.
Columns with uniaxial eccentric loading- A uniaxial eccentrically loaded column is one in which the axis of vertical loads does not coincide with the C.G. of the cross-section of the column, but rather acts eccentrically on either the X or Y axis of the column cross-section. These types of columns are generally used in columns rigidly connected to beams from one side such as edge columns.
Columns with biaxial eccentric loading- A biaxial eccentrically loaded column is one in which the vertical loads on the column do not correspond with the centre of gravity of the column cross-section and do not act on either X or Y-axis. These types of columns are used in columns with beams rigidly connected at right angles at the top of columns such as corner columns.

Types of Columns Based on the Slenderness Ratio

The slenderness ratio of a compression member is defined as the ratio of its effective length to its lateral dimensions. It provides a measure of the column’s susceptibility to buckling failure. Columns can be divided into two types of columns based on the slenderness ratio.

Short column- The column is referred to as a short column if the ratio of the effective length of the column to the least lateral dimension is less than 12. The failure of a short column is due to crushing (pure compression failure).
Long columns- A long column is defined as one in which the ratio of the effective length of the column to the least lateral dimension is more than 12. Bending or buckling is how a long column fails.

Types of Columns Based on the Type of Material

Columns can also be classified based on the material used for their construction. Stone, brick, concrete, timber, steel, etc. are commonly used to make columns. Under this classification, different types of columns are listed below.

Reinforced concrete column
Steel column
Timber column
Stone Column
Brick column

FAQs on Types of Columns

What are columns in a structure?

Different types of columns are used in structures. A column is a vertical structural element that mostly carries compression loads. It may carry loads to a floor or foundations from a ceiling, floor slab, roof slab, or beam. Columns are generally defined as vertical compression members having an effective length greater than three times the least lateral dimension.

How columns are classified?

Columns can be categorized into different types based on different parameters. The different types of columns based on various factors are listed below:

Based on the type of reinforcement - Tied columns, spiral columns and composite columns
Based on shape - square/rectangular section, circular section, L section, T section, Y section, etc.
Based on the type of loading - Axially loaded columns, Uniaxially eccentrically loaded columns and Biaxially eccentrically loaded columns
Based on the slenderness ratio - Short and long columns
Based on the material - Reinforced concrete columns, steel columns, timber columns, stone columns, and brick columns.

What are short and long columns?

Short and long columns are types of columns classified based on the slenderness ratio. The slenderness ratio of a member is defined as the ratio of its effective length to its lateral dimension and it provides a measure of the susceptibility of a member to buckling failure.

Columns having a ratio of effective length to the least lateral dimension less than 12 are termed short columns. These types of columns fail due to crushing. Columns having a ratio of effective length to the least lateral dimension greater than 12 are classified as long or slender columns. These types of columns undergo buckling failure.

Why do spiral columns take more loads than tied columns?

Tied columns are the types of columns in which the main longitudinal bars are enclosed within closely and uniformly spaced lateral ties. Whereas, the spiral columns are the types of columns in which the main longitudinal bars are confined within continuously wound spiral reinforcement. The spiral reinforcements provide lateral support and delay failure due to axial load. When load eccentricities are small, spiral columns offer greater toughness and ductility to tied columns, allowing them to carry heavier loads.

What is the difference between uniaxial and biaxial loaded columns?

Uniaxial eccentrically loaded columns are the types of columns in which the axis of vertical loads does not coincide with the C.G. of a cross-section of the column, but rather acts eccentrically on either the X or Y axis of the column cross-section. This causes the column to be subjected to a moment on one of the axes along with the axial load.

Biaxial eccentrically loaded columns are the types of columns in which the vertical loads on the column do not correspond with the centre of gravity of the column cross-section and do not act on either axis. This leads to the column being subjected to moment on both the axis along with the axial load.