Complete RCC column design Guide – Numerical Example as per IS Code

Definition

Column is defined as a vertical compressive member which is subjected to a compressive force.

It shall called a column if its effective length will be three times the least lateral dimension.

If the effective length of the column is not at least three times its lateral dimension then it is known as Pedestal.

The inclined column subjected to axial loading is known as Strut.

In this post, I Have provided also the RCC column design pdf file which contains further more information than this post. You can download this.

Shape of Cross Section of Column

• Square
• Rectangular
• Circular
• Pentagonal
• T-Shape
• L-Shape etc.

Materials of Column

• Timber
• Masonry
• R.C.C
• Steel Column
• Composite Column

Types of Loading on Column

1. Axially Loaded Column
2. Eccentrically Loaded Column

Eccentrically Loaded Column further divided into two type

1. Uniaxial Loaded Column
2. Biaxial Loaded Column

Types of Column- Slenderness ratio

1. Short Columns
2. Long Column

Effective length of Compression members

Types of Reinforcement in Column

Longitudinal Reinforcement

The Steel Rod placed longitudinally in a column is known as Longitudinal reinforcement. It is also known as main rod of a column.

Function of Longitudinal Reinforcement

• It spread the compressive load to concrete.
• It resists Tensile Stress
• It Provides Ductility to column
• It reduces the effect of shrinkage.

Lateral or Transverse Reinforcement

The steel rod provided along the lateral dimension of the column is known as lateral or Transverse reinforcement.

Function of transverse Reinforcement

• It prevents buckling of the column due to excess load.
• It holds all the main or transverse reinforcement
• It Resists horizontal or diagonal tension on the column.

Types of Lateral Reinforcement

Column with lateral ties

Column with Spiral ties

Longitudinal Reinforcement to RCC column design – Specification As Per- IS456-2000

Cover- The nominal cover for a longitudinal reinforcement bar in a column should not be less than any of the following,

A) 40 mm

B) The diameter of the bars

Minimum Eccentricity:- The Minimum eccentricity to design a column should be,

Requirement of Longitudinal Reinforcement for RCC column design

1.The cross sectional area of longitudinal reinforcement in a column should not less than 0.8 percent and more than 6 percent of the gross cross sectional area of the column.

2.The minimum numbers of longitudinal bars in a column should not be less than four in rectangular column and less than six in circular column.

3.The longitudinal bars should not be less tha 12 mm in diameter.

4.The spacing of longitudinal bars should not be more than 300 mm.

Requirement of Lateral Reinforcement of Column

1.The diameter of lateral ties should be greater among,

1.(¼)th of the diameter of the largest longitudinal bars.

2.6 mm

2. The Pitch or spacing of the lateral ties should not be greater than the following.

1.Least lateral dimension of the column.

2.16 times the diameter of the smallest longitudinal bars.

3.300 mm

3. The diameter of spiral or helical reinforcement bars should be greater among,

1.(1/4)th of the diameter of the largest longitudinal bar.

2.6 mm

4.The pitch of spiral reinforcement should not be more among,

1.75 mm

2.(1/6)th of the diameter of the core of concrete.

Design of RCC Short Column- Axial Loading

Design of RCC Short Column- Unaxial Loading

Download RCC column design pdf

This RCC column design pdf file contains also numerical of,

• Design of Short Column for Biaxial Loading
• Design of Long Column.

Further, if you have any questions or help, then please provide your email address and question in the comment box below.

I hope this post remains helpful for you.

Happy Learning – Civil Concept

Contributed By,

Civil Engineer – Ranjeet Sahani

Read Also,

Column reinforcement details- As Per- IS456-2000

Short column and Long column- Difference by the Slenderness ratio

Effective length of Column- Under Different condition of Fixed-Rotation

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