Question

As per IS 456:2000, the cross-sectional area of longitudinal reinforcement in a column  shall NOT be:  
1. less than 1 per cent and more than 7 per cent of the gross sectional area
2. less than 0.8 per cent and more than 6 per cent of the gross sectional area
3. less than 1.2 per cent and more than 4 per cent of the gross sectional area
4. less than 2 per cent and more than 8 per cent of the gross sectional area
5. less than 4 per cent and more than 10 per cent of the gross sectional area

Answer 1

Correct Answer - Option 2 : less than 0.8 per cent and more than 6 per cent of the gross sectional area

Explanation

As per IS 456: 2000, clause 26.5.3.1,

Longitudinal reinforcement in a column:

Percentage of steel:

The cross-sectional area of longitudinal reinforcement shall be

• not less than 0.8 per cent of the gross cross-sectional area of the column
• nor more than 6 per cent for unlapped bars of the gross cross-sectional area of the column
• nor more than 4 per cent for lapped bars of the gross cross-sectional area of the column

 

The minimum diameter of longitudinal reinforcement bars:

The main longitudinal reinforcement bars used in column shall not be less than 12 mm in diameter.

The minimum number of longitudinal bar:

The minimum number of the longitudinal bar provided in column shall be

• four in rectangular columns
• six in circular columns.