Types of Columns

Types of Columns: Dimensions and Uses

 

Columns are defined as long slender member load axially in compression and having lateral dimensions very small as compared to their lengths.

A vertical compression member is called a column. If load passes through the longitudinal axis coinciding with the CG of the column, it is called the axially loaded column, otherwise eccentrically loaded column.

Columns are the building structures connected to different footings to transfer the load of the building to the footings of the buildings.

 


 

  1. Types of Columns  

There are different types of columns, which are listed below depending on various factors:

 

  a. Based on Loading  

Types of Columns based on loading are as follows:

a. Axially Loaded Columns

When the compressive vertical loads lie along the centroidal axis of the column, it is known as an axially loaded column. This type of column without bending is not available in the real world so much.

 

Axially Loaded Columns

 

b. Eccentrically Loaded Column: Uniaxial

When the loads on the column are lying at a distance ‘e’ from the centroid of the column cross-section, the column is known as an eccentrically loaded column. In a uniaxial eccentrically loaded column this distance ‘e’ could be along the x-axis or y-axis. The eccentric loads result in moments along the x-axis or y-axis at the same time.

 

Eccentrically Loaded Column: Uniaxial

 

c.  Eccentrically Loaded Column: Biaxial  

In this type of column, loads are loaded at any point of cross-section but not on the axis. The eccentric loads result in moments about both the x- and y-axes at the same time.

 

Types of Columns

 

  b. Based On Column Ties  

Types of Columns based on column ties are as follows:

a. Tied Column

The longitudinal bars are bound together with smaller bars are the tied column. These smaller bars are placed at uniform gaps up the column. Steel ties in columns enclose the main longitudinal bars.

Over 95 % of all columns in structure in non-seismic regions are bounded columns.

 

Based On Column Ties

 

b. Spiral Column

Spiral columns include spirals to support the main longitudinal reinforcement. Spiral is spring-type reinforcement used in the buildings. The main bars are kept in a circle and ties are removed by spirals.

Spiral columns are utilized when high strength and/or high ductility are needed. Because the spiral acts to withstand the lateral expansion of the column bars under high axial loads. The main bars are kept in a circle and ties are removed by spirals. Spiral columns are utilized more highly in seismic regions.

 

 

  c. Based On Slenderness  

Types of Columns based on slenderness are as follows:

a. Short Compression Block or Pedestals

A pedestal is a compression member containing a height lower than three times its least lateral dimension. Pedestals require not to be reinforced and may be prepared with plain concrete.

 

Short Compression Block or Pedestals

 

b. Short Reinforced Column

The slenderness ratio is the ratio of effective length to the least lateral dimension. It is less than 12 in the short reinforced column. Short columns collapse because of the crushing or yielding of the steel bars. The loads that a short column may hold are based on the dimension of the cross-section and the strength of materials. The short columns provide low flexibility.

 

Short Reinforced Column

 

c. Long Reinforced Column

The slenderness ratio is more than 12 long columns and this type of column is also termed the slender column. As the slenderness raise, bending deformation raises. The long column collapse due to the buckling effect which decreases load-bearing capacity.

 

Long Reinforced Column

 

  d. Based On the Shape of the Cross Section  

Types of Columns based on the shape of the cross-section are as follows:

Geo-matric Shaped

Column segments can be rectangular, round, square, octagonal, or hexagonal as per need.

Tied columns can be square and rectangular while spiral columns are made of circular shapes. Circular columns are utilized when higher elevation is required like in piles, bridges pillars. Circular columns give a smooth and aesthetic finish. On the other hand, rectangular columns are available in residential and official buildings. They are easy and less costly to mold.

 

L-Shaped

This type of column isn’t very popular. The L-shaped column can be utilized as a corner column in a framed structure. This design of the column can be the best replacement to withstand both axial compression and biaxial bending of corners.

 

L-Shaped

 

V-Shaped

In the trapezoidal structure, this type of column can be utilized. V-shaped columns require more materials relatively.

 

L-Shaped V-Shaped T-Shaped

 

T-Shaped

T-shaped columns are utilized in bridge pillars depending on design criteria.

 

 

  e. Based on Construction Materials  

Types of Columns based on construction material are as follows:

a. Reinforced Concrete Column

Reinforced concrete columns are the most widely used columns for framed structures. The reinforced concrete column is made of concrete as a matrix. The steel frame is attached to the concrete.

Concrete support the compressive load and reinforcement withstand the tensile load. The reinforcing materials can be prepared of steel, polymers, or other composite materials.

For a strong, ductile, and durable work the reinforcement requires to have features like thermal compatibility, high resistance to tensile stress, good bond to concrete, anti-corrosive, etc.

 

Types of Columns: Dimensions and Uses

 

 

b. Composite Column

Composite columns are prepared to utilize a different combination of structural steel and concrete. The interactive and integral behavior of concrete and the structural steel elements constructed the composite column into a very stiff, more ductile, cost-effective, and so a structurally systematic member of building and bridge construction. The composite type of column has the best capacity to withstand fire and corrosion resistance.

 

Composite Column

 

c. Steel, Timber, Brick Column

Steel columns are made of steel entirely. Steel, Timber, and Brick columns are utilized in aircraft constructing warehouses, indoor shipyards, etc. Timber columns are prepared of wood timber. They give an aesthetic appearance giving a feeling of space and openness.

Timber columns are prepared for housebuilders, reception areas, and refurbishment features. Brick columns are available in masonry structures. They can be reinforced with concrete to expand strength or can be unreinforced.

The brick columns can be round-shaped, rectangle, square, or elliptical in cross-section.

Steel, Timber, Brick Column

 

  f. Based on Frame Bracing  

Types of Columns based on frame bracing are as follows:

a. Braced Column

Columns can be components of a frame that is braced or unbraced sideways. Lateral stability to a structure as a whole is given by bracing. Bracing can be done by utilizing shear walls or bracings in the building frame. In braced frames, comparative transverse movement of the upper and lower ends of a column is saved. Braced columns safe gravity loads and shear walls safe lateral loads and wind loads.

Based on Frame Bracing

 

b. Unbraced Column

Unbraced columns can withstand both gravity load and lateral load. As a result, the load capacity of the column decreases.

Types of Columns: Dimensions and Uses

 

 

  g. Other Types of Columns  

 

a. Prestressed Concrete Column

Prestressed columns can be used as an extension of the reinforced concrete columns when bending moments due to wind and earthwork forces, eccentric loads, or frame action are utilized to columns. Prestressing transforms a cracked section into a non-cracked one and withstands notable bending. This type can be available useful when the column is a high slender column and precast column.

 

Prestressed Concrete Column

 

b. Greek And Roman Columns

Greek and Roman architecture made use of four major styles of columns for their buildings and temples.

These four types of columns were Doric, Ionic, Corinthian, and Tuscan. These columns look straight and uniform from a distance. But up close, they might actually tilt a bit, or lean left or right.

 

Greek And Roman Columns

 


  2. Dimensions of Columns in Different Countries  

Country Column Size (MM X MM)
USA225 x 225
India229 x 305
UK254 x 254
Philippines225  x 300
Nepal305 x 305
Japan400 x 280

 


  3. Uses of Columns  

Here are the following uses of columns:

1. It is used to support arches and beams.

2. It is used to increase the aesthetic beauty of buildings.

3. It is used to transfer the load to the foundation.

 


 

Read Also: Lap Length