Design of Circular Column || Spirally Reinforced Axially Loaded Short Column || RCC

Описание: Circular columns are mostly used in piling and elevation of the buildings for aesthetic purposes. In a circular column, more than 4 longitudinal steel bars are used as a reinforcement bar and its bending resistance is generally higher than the square or rectangular column.
The most regularly used shapes for columns in building projects are rectangular shape, circular shape and square shape. In most of the projects, rectangular column shape is preferred over circular columns. Some times square columns are also preferred over circular columns.
Different Types of RCC Columns

1 Classification of the Column based on its Cross Section.
Square Column or Rectangular Column
Circular Column
T Shape Column
L Shape Column
Y Shape Column
2 Classification of the Column based on its Loading.
Axially Loaded Column
Axially Loaded and Uniaxial Bending Column
Axially Loaded and Biaxial Bending Column
3 Classification of the Column based on its Length and Behaviour.
Short Column
Long Column
4 Classification of the Column based on its Longitudinal Reinforcement.
Tied Column
Spiral Column
Composite Column

Square or Rectangular Column: They are commonly used in the construction of buildings and heavy structures. It is much effortless to construct and cast rectangular or square columns than circular ones because of the ease of shuttering and to support it from collapsing due to pressure while the concrete is still in flowable form.

Circular Column: Circular columns are mostly used in piling and elevation of the buildings for aesthetic purposes. In a circular column, more than 4 longitudinal steel bars are used as a reinforcement bar and its bending resistance is generally higher than the square or rectangular column.

L and T shaped Column: Generally, the L-shaped column is utilized in the corners of the boundary wall and has similar characteristics of a rectangular or square column. The T-shaped column is utilized based on the design requirements of a structure. It is widely used in the construction of bridges.

Tied Column: This is usually constructed from reinforced concrete. Longitudinal reinforcements are confined within closely spaced tie reinforcement. If ties are spaced too far apart, the column will experience shear failure and barreling in between ties. It is estimated that 95% of all columns in buildings are tied columns

Spiral Column: When spiral columns are reinforced with closely and uniformly spaced spiral reinforcement, they are also known as spiral columns. Mostly the spiral columns are providing to support in the transverse direction and prevent the column from barreling. Spirally reinforced columns generally consist of 6 bars as longitudinal reinforcement.

Composite Column: These columns consist of structural steel or cast iron column enclosed with concrete, reinforced with longitudinal as well as spiral reinforcement. Composite columns are widely used in truss structures to avoid the corrosion of steel. This type of column has more adequate strength with a fairly small cross-section, in addition, to exhibit good fire performance.

Axially Loaded Column: If vertical axial loads act on the center of gravity of the cross-section of the column, then it is termed as an axially loaded column. The axially loaded column is rare in construction since coinciding vertical loads on the center of gravity of the column section is not practical.

Uniaxial Eccentrically Loaded Column: The axis of vertical loads doesn’t cross with C.G. (center of gravity) of a cross-section of the column, but rather act eccentrically either on the X or Y axis of the column cross-section, then it is called a uniaxial eccentrically loaded column. A column with this loading system used in the case of columns rigidly connected beam from one side only such as edge columns.

Biaxial Eccentrically Loaded Column: When vertical loads on the column do not coincide with the center of gravity of the column cross-section and do not act on wither axis (X and Y axis), then the column is called a biaxial eccentrically loaded column. Columns with biaxial loading are mostly used in corner columns with beams rigidly connected at right angles at the top of columns. These types of columns are used in special types of construction.

Short Column: If the ratio of the effective length of the column to the least lateral dimension is less than 12, the column is called the short column. A short column fails by crushing of the concrete (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.