A compression member i.e. column is an important element of every reinforced concrete structure. These are used to transmit the load of superstructure to the foundation safely.
A column is a vertical compression member which is mainly subjected to axial loads and the effective length of which exceeds three times its lateral dimension.
Types of column
- Short Column
- Long Column
What is slenderness ratio?
The slenderness ratio is the ratio of the effective length of the column to the least lateral dimension of the column.
Short column
The column is considered as short column when the slenderness ratio of column i.e. ratio of effective length to its least dimension,
Lex = Effective length of column in minor axis
Ley = Effective length of column in minor axis
d = Depth of column in respective axis b = Breadth of column
Long column
The column is considered as long column when the slenderness ratio of column is greater than 12.
Lex = Effective length of column in minor axis
Ley = Effective length of column in minor axis
d = Depth of column in respective axis
b = Breadth of column
Difference between short column and long column
| SN. | Short Column | Long Column |
| 1 | A column is said to be short if the ratio of effective length to its least lateral dimension is less than or equal to 12. | A column is said to be long if the ratio of effective length of column to its least lateral dimension is greater than 12. |
| 2 | The ratio of effective length of short column to its least radius of gyration is less than or equal to 40. | The ratio of effective length of a long column to its radius of gyration is greater than 40. |
| 3 | Buckling tendency is very low. | Long and slender columns buckle easily. |
| 4 | The load carrying capacity is high as compared to long column of same cross-sectional area. | The load carrying capacity of a long column is less as compared to short column of same cross- sectional area. |
| 5 | The failure of short column is by crushing. | The column generally fails in buckling. |
Read Also,
Design of compression members- Design of Column
Effective length of Column- Under Different condition of Fixed-Rotation
10 Cause of crack in concrete structure like Column, Beam, Slab, etc
