Question

As per IS 1343 – 1980, the minimum 28 days compressive strength for pre-tensioned member is:

1. 50 N/mm2
2. 30 N/mm2
3. 25 N/mm2
4. 40 N/mm2

Answer 1

Correct Answer - Option 4 : 40 N/mm2

Explanation

 the minimum 28 days compressive strength for pre-tensioned member is: M 40 or 40 N/mm2

A minimum grade of concrete to be used in the design of the prestressed concrete structure as per IS 1343 is as below:

1. For Post-tensioning minimum grade of concrete used is M-30.

2. For Pre-tensioning minimum grade of concrete used is M-40.

Cover to be used in the design of the prestressed concrete structure as per IS 1343 is as below:

1. For Posttensioning minimum cover to be used is 30 mm.

2. For Pre-tensioning minimum cover to be used is 20 mm.