Several types of columns are used in building construction, the effective depth of a column is at least 3 times its lateral dimension.
Column is a vertical member that carries the load of the structure from beam and slab to the foundation.
The column carries the axial load in compression because it is an extremely essential part of the structure so the structure collapses as a result of column failure.
Sometimes columns carry bending moments at one or both cross-section axes.
Different loads corresponding to snow loads, wind loads, horizontal forces, or thrusts may cause bending within the column.
Columns are usually constructed from materials such as stone, brick, block, concrete, metal, or others that have corrosive strength.
Different Types of Columns used in Construction:
Different types of columns are used in construction industries, they can be classified based on several conditions as follows:
Classification of Columns Based on the Shape:
Following are the types of columns based on size:
1.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 is mostly used for aesthetic functions within the elevation of buildings.
In this column, more than 4 longitudinal steel bars are used as a reinforcement strip and its bending resistance is usually greater than square or rectangular column.
These columns are largely used as bridge columns because of good resistance against deflection.
3.L and T shaped column:
Generally, L-shaped columns are used in the corners of the boundary wall and have similar characteristics like rectangular or square column.
T-shaped columns are used in the bridges based on the design requirements on large scale construction.
Classification of Columns Based on the Reinforcement:
Followings are types of columns based on the shape:
This tied column is normally constructed from reinforced concrete, while longitudinal reinforcements are closely restricted throughout the tie reinforcement.
If the ties are placed too far, the column will experience the shear failure and intersection between the ties.
It is estimated that 95% of all columns in buildings are tied columns.
Spiral column is reinforced with spiral reinforcement closely and evenly spread also called spiral columns.
Most spiral columns are provided to support the transverse direction and prevent the column from barring.
Normally reinforced columns usually have 6 bars as longitudinal reinforcement.
Composite column consists of structural steel or cast iron column surrounded by concrete, reinforced with longitudinal as well as spiral reinforcement.
Composite columns are widely used in truss structures to avoid corrosion of steel.
These types of column has more adequate strength, with smaller cross-sections to demonstrate good fire performance.
Classification of Columns Based on Loading:
Following are the types of columns based on loading:
7.Axially filled column:
If the vertical axial load acts at center of gravity of the column’s cross-section termed as an axially loaded column.
This column is rare in construction because it is not practical to settle the vertical load on the center of gravity of the column section.
The internal column of symmetrical multi-story buildings with floor slabs from each side is an example of this column.
8.Uniaxial Eccentrically Loaded Column:
The axis of vertical load does not cross with C.G. (Center of gravity) of a cross-section of the column, but also acting either eccentrically on the X or Y axis of the column cross-section is called a uniaxially loaded column.
With this loading system, the column is attached to the beam from one side of the column.
9.Biaxial eccentric column:
When the vertical load on the column doesn’t coincide with the center of gravity of the column and it doesn’t act on the shock axis (X and Y axis), the column is known as a biaxial eccentric column.
Columns with biaxial loading are principally used in corner columns with beams rigidly combined at right angles to the top of the columns.
These types of columns are used in particular types of buildings.
Classification of Columns Based on Slenderness Ratio:
Followings are types of columns primarily based on slenderness ratio:
If the ratio of the efficient length of the column to the least lateral dimension is lower than 12, then the column is known as a short column.
The crushing of concrete (pure compression failure) causes the failure of a small column.
If the ratio of the effective size of the column to the least lateral dimension is bigger than 12, it is known as a long column.
A long column fails by bending or buckling, they are weaker than shorter columns of a similar cross-sectional area which are generally not preferred.
Classification of Column Based on Construction Materials:
Followings are types of columns based on slenderness ratio:
12.Reinforced Concrete Column:
Reinforced concrete column are reinforced with steel are known as reinforced concrete columns.
These columns are used prominently in building construction, concrete is strong in compression and weak in tension.
Subsequently, steel reinforcement is provided to extend its tensioning capability.
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.
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.
The brick column is generally used in load-bearing structures as it plays an important role in supporting and enhancing the stability of the masonry structure.
Sometimes, the construction of brick masonry columns above the concrete column enhances its aesthetic appearance.
These types of columns may have different cross-sections such as round, rectangle, square or elliptical.
Block column is made of AAC blocks or cement concrete blocks, these column structural weight is lower compared to concrete columns.
The stone column is made using stone and rubble commonly used to improve the aesthetic appearance of a household.
Also read: Types of Foundation, Types of Structures & Types of Footing
The various types of columns are generally designed to evenly distribute compressed axial loads and additional forces such as ice, wind, and to maintain the structure in earthquakes or any other forces.