2.2. Criteria for Acceptance (IS 456:2000)

Try these first

1. 1.

   What does 'fck' represent in concrete mix design?

   Hint

   Think about the strength point where only a small percentage of samples fall below.

2. 2.

   Define workability.

   Hint

   Consider how well concrete can flow and fill forms.

3. 3.

   What is considered the minimum individual strength for acceptance of concrete mixes?

   • 15 MPa
   • 18 MPa
   • 21 MPa

   Hint

   Remember, it’s the limit set for individual tests.

4. 4.

   True or False: Durability is solely determined by compressive strength.

   • True
   • False

   Hint

   Think about what else contributes to durability.

5. 5.

   Given a scenario where you've tested seven concrete samples yielding results of: 26, 24, 25, 21, 20, 23, and 22 MPa, calculate whether you can approve this mix for use.

   Hint

   Assess average strength and individual results!

6. 6.

   If you decrease the water-cement ratio from 0.50 to 0.42 to enhance durability, what factors should you monitor?

   Hint

   Think about how cement interacts with water and aggregates.