TYPES OF COLUMNS USED IN CONSTRUCTION
Different types of columns are used in various parts of structures. A column is a vertical structural element used to support compression loads. Loads may be transferred from a ceiling, floor slab, roof slab, or beam to a floor or foundation. Columns usually carry bending moments along one or both cross-section axes.
Types of Columns
In structures, different column types are used. Columns can be categorized depending on different factors, which include:
A. BASED ON THE SHAPE
Circular columns are commonly utilized in piling and construction elevations for aesthetic purposes.
A circular column contains more than four longitudinal steel bars as a reinforcement bar, and it can withstand higher bending forces than a square or rectangular column.
Due to their high resistance to bending, circular columns are commonly used as bridge pillars.
The L-shaped column, which is comparable to a rectangular or square column, is typically used at the corners of the boundary wall. The T-shaped column is used depending on the structure’s design requirements. It’s commonly used in the construction of bridges.
They are frequently utilized in the construction of buildings and other large structures.
Because of the ease of shuttering and supporting the column from collapsing due to pressure while the concrete is still in flowable form, rectangular or square columns are considerably easier to design and cast than circular ones.
The square or rectangular ones are preferable and less expensive.
B. BASED ON THE TYPE OF REINFORCEMENT
These columns are made up of structural steel or cast iron columns that are concrete-encased and reinforced with longitudinal and spiral reinforcement.
To prevent steel from corroding, composite columns are commonly used in truss construction. This type of column has appropriate strength and a fairly small cross-section, as well as good fire performance.
READ MORE: STRUCTURAL MEMBERS OF A BUILDING
Spiral columns are also known as “spiral reinforcement columns” when they are reinforced with closely and consistently spaced spiral reinforcement.
Generally, spiral columns provide transverse support and prevent the column from barreling. Spirally reinforced columns typically have six bars as longitudinal reinforcement.
Reinforced concrete is commonly used to construct this type of column. Closely spaced ties reinforce the longitudinal reinforcement. It is estimated that approximately 95% of all construction columns are tied.
C. BASED ON THE TYPE OF LOADING
7. Axially Loaded Column
An axially loaded column is one in which vertical axial loads act on the center of gravity of the cross-section of the column.
An axially loaded column is uncommon in construction because imposing vertical stresses on the column section’s center of gravity is impractical.
This type of column includes the interior columns of multi-story structures with symmetrical loads from floor slabs on all sides.
8. Biaxial Eccentrically Loaded Column
A biaxial eccentrically loaded column is one in which vertical loads on the column do not correspond with the center of gravity of the column cross-section and do not operate on the wither axis (X and Y axis).
Biaxially loaded columns are typically utilized in corner columns with beams permanently connected at right angles at the top of the columns. These columns are used in specialized construction.
9. Uniaxial Eccentrically Loaded Column
The axis of vertical loads does not intersect with the C.G. (center of gravity) of a column’s cross–section but mostly acts eccentrically on the X or Y axis of the column’s cross–section. It is referred to as a uniaxial eccentrically loaded column.
A column with this loading mechanism is utilized in the situation of rigidly attached beam columns from just one side, such as edge columns.
D. BASED ON THE SLENDERNESS RATIO
10. Long Column
A long column is one whose effective length exceeds the least lateral dimension by a factor of 12. A long column might fail through bending or buckling. Long columns are weaker than short columns with the same cross-sectional area and are not often used.
11. Short Column
A column is called a short column if the effective length of the column to the least lateral dimension is less than 12. A short column fails due to concrete crushing (pure compression failure).
E. BASED ON THE CONSTRUCTION MATERIALS
12. Reinforced Concrete Column
Reinforced concrete columns are columns that have steel reinforcement. This column is commonly found in the construction of buildings. Concrete has a high compressive strength but a low tension strength. As a result, steel reinforcement is added to improve the stress capacity of the structure.
13. Brick Column
Columns made of brick masonry are commonly employed in load-bearing constructions. It is critical in maintaining and strengthening the masonry building’s stability. Construction of brick masonry columns over a concrete column can sometimes improve its visual look. Brick masonry columns can have round, rectangular, square, or elliptical cross-sections.
14. Block Column
Block columns are made of AAC or cement concrete blocks. The structural weight of a block column is lower than that of a concrete column.
15. Steel Column
A steel column is a particular type of column built of steel. There are significant global trends in steel structure building. In comparison to concrete, steel structures are more flexible, sturdy, and long-lasting. Steel columns come in a variety of styles, including the T-section steel column, which is the most widely used in steel construction.
16. Stone Column
The stone column refers to the types of columns that are constructed from stones and rubble. They are most often used to improve the house’s visual appearance.
17. Timber Column
The term “timber column” refers to a column composed of wood. In the past century, timber columns became popular.
Timber is commonly seen in older structures since it was the only readily available construction material in the period.