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,

L_{ex} = Effective length of column in minor axis

L_{ey} = 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.

L_{ex} = Effective length of column in minor axis

L_{ey} = 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