DIFFERENT TYPES OF COLUMNS USED IN CONSTRUCTION

A vertical member whose effective length is greater than 3 times Its least lateral dimension carrying compressive loads is called as a column. Columns transfer the loads from the beams or slabs to the footings or foundations. 

The Column is a vertical member which transmits loads of a structure from beam and slab to the foundation. The effective depth of a column exceeds three times its least lateral dimension. Usually, the column carries axial loads in compression. Columns are very important components of a structure. 

Failure of the column results in the collapse of the structure. There are different types of columns used in building construction.

Generally, columns carry axial loads and therefore are designed for compression. Other loads like snow load, wind load, or other horizontal forces or thrusts can cause bending in the columns. Columns then need to be designed for axial load and bending.

Columns are typically constructed from materials like stone, brick, block, concrete, steel, etc. which have good compressive strength.

Importance of Column Construction:

• Because columns bear axial loads, they are intended to withstand compression stresses.
• Other loads, such as snow, wind, or other horizontal forces, might induce bending in the structure. Thus provisions are included to prevent the collapse or settlement of structural columns.
• The column is often constructed to equally distribute compressive axial load and other forces such as snow and wind to the foundation, allowing the building to withstand earthquakes and other pressures.
• We will create a tiny structure of random rubble masonry to a particular height. Still, we will not construct a multi-story building out of random rubble masonry since the structure must be capable of transmitting heavyweight to the foundation’s base.

Types of Columns in Building Construction

Columns are classified based on several conditions which include:

1. Based on Types of Reinforcement
2. Based on Types of Loading
3. Based on Slenderness Ratio
4. Based on Shape
5. Based on Construction Material

 

Based on Types of Reinforcement

• Tied Column

This kind of column is usually made of reinforced concrete. Longitudinal reinforcement is contained within tie reinforcement that is tightly spaced. It is estimated that 95% of all construction columns are tethered.

• Spiral Column

When the main longitudinal bars of the column are enclosed with in closely spaced and continuously wound spiral reinforcement, it is called as a spiral column.

• Composite column

When the longitudinal reinforcement is in the form of structural steel section or pipe with or without longitudinal bars, it is called as a composite column. This type of column have high strength with fairly small cross section, in addition to exhibit good fire performance.

Based on Types of Loading

• Axially Loaded Column

An axially loaded column has vertical axial loads acting on the center of gravity of the cross-section of the column. Because it is impractical to align vertical loads on the center of gravity of the column cross-section, axially loaded columns are uncommon in construction. This column can be seen inside multi-story buildings with symmetrical loads from floor slabs on all sides.

• Column with Uniaxial Eccentric Loading

When vertical loads do not coincide with center of gravity of column cross section, but rather act eccentrically either on X or Y axis of the column cross section, then it is called uniaxially eccentric loading column. Column with uniaxial loading are generally encountered in the case of columns rigidly connected beam from one side only such as edge columns.

• Column with Biaxial Eccentric Loading

When vertical on the column is not coincide with center of gravity of column cross section and does not act on either axis (X and Y axis), then the column is called biaxially eccentric loaded column. Columns with biaxial loading is common in corner columns with beams rigidly connected at right angles at the top of columns.

Based on Slenderness Ratio:

• Short Column

The column is known as a short column if 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 Column

If the ratio of the effective length of the column to the least lateral dimension exceeds 12, it is called a long column. A long column fails by bending or buckling. Long columns are weaker compare to short columns of the same cross-sectional area and not generally preferred.

Based on Shape Shape of Reinforced Concrete Column

Square or Rectangular Column

Square column is generally used within the buildings construction and heavy structures. Due to the ease of shuttering and to prevent it from collapsing due to pressure, rectangular or square columns are much easier to construct and cast, while concrete is still in a flowable form. Squares or rectangles are better in cost and cheaper.

• Circular column

They are specially designed columns, they are mostly used in piling and elevation of the buildings. Why we use it in elevation? In order to avoid edges, we use this type of columns. they are also provided in sit out areas, auditoriums or fire assembly zones, where you have enough space for them not to hinder any movement of people or look bad with flat surfaces You can find circular columns as pillars of Bridges because there you don’t need to flush them to anything. Also circular looks aesthetic there.

• L-Shape Column

Commonly, L-shaped column is utilized in the corners of the boundary wall and has similar characteristics of a rectangular or square column.

• V- Type Column

As a name itself, it showcasing the column is in V shape and generally used if the shape of the room is in trapezoidal. As it requires more amount of concrete when compared to the other columns.

Based on Construction Material:-

• Reinforced Concrete Column

A column in which is reinforced with steel are known as reinforced concrete column. This column majorly used in building construction. Concrete is strong in compression and weak in tension. Therefore, steel reinforcement is provided to increase its tension capacity.

• Steel Column:

The column made of steel is known as steel column, there are huge trends in steel structure manufacturing in the world. The steel structure is comparatively more flexible, stronger and durable than the concrete structure. There are different types of steel columns such as T section steel columns which are most commonly used in steel structure.

• Timber Column:

The columns made of wood are known as wooden columns, they have been popular in the last century. Timber is usually seen in old buildings since that time it is the only building materials that might be readily available. The timer is a strong and durable construction material if it is given proper treatment used to extract moisture from wood which gives better strength and reduces weight.