Basic Thumb Rules For RCC Column Design

This civil engineering article focuses on the basic thumb rules for a column layout. Though the design of RCC columns is created on the basis of the total load on the columns but there are also some thumb rules to get rid of probable errors.

Considerations should be given on the following thumb rules :

1. Size of the Columns
2. Distance between Columns
3. Alignment of columns

First Thumb rule - Size of the columns

a. The size of the columns is influenced by the total load on the columns.
b. Least size of the column should not be lower than 9”x9”.
c. The standard size of the columns for a single storey structure with M15 grade of concrete is 9”x9”.
d. When 9”x9” column size is required for 1 and half storey structure, it is recommended to employ M20 grade concrete.
e. A secure and structurally strong column size for a 1 and half storey structure should not remain under 12”x9” with M15 grade concrete.

Second Thumb Rule - Spacing amount the columns

a. It is necessary to keep equivalent spacing among the centres of two columns. A column layout should be provided on a grid.
b. The spacing among two columns with 9”x9” size should not remain in excess of 4m centre to centre of column.
c. When bigger barrier free distances are required then the column with bigger size should be applied.

The size of the columns is raised due to the following reasons:

1. Increase in the distance among two columns (It raises the dimensions of the columns along with the depth of the beam.)

Also Read: Some useful tips to design RCC columns

2. Height of the building (Increase in the number of floors is directly proportional to the dimensions of the columns.

Third Thumb Rule - Alignment of Columns

There should be a rectangular grid for placing the columns to get rid of errors and make the column placement process perfect.

The columns are mainly arranged in following ways :

1. In a straight line through a grid
2. In a circular fashion for circular buildings.

Zigzag arrangement of columns should not be followed for making structural design. It should be kept in mind that when columns are constructed, beams are placed connecting the columns.

The following major problems are occurred due to the Zigzag column placement:

1. Unbalanced load transfer
2. Errors in wall construction
3. Errors in placing beams

Don't forget to watch the following exclusive video tutorial for RCC column design:-

Video Source: Civil Engineers