Question

The workability of concrete can be increased by which of the following?
1. Increasing the quantity of coarse aggregate without altering the total aggregate quantity.
2. Decreasing the quantity of coarse aggregate and at the same time correspondingly increasing the quantity of fine aggregate.
3. Using round aggregate.
Select the correct answer using the codes given below:

• A. 1 and 3 only
• B. 1 and 2 only
• C. 2 and 3 only
• D. 1, 2 and 3

Answer 1

The correct option is A 1 and 3 only

For the same water content, decreasing the quantity of coarse aggregate and correspondingly increasing the quantity of fine aggregate decreases workability . Coarse aggregate gives higher workability because of less friction among particles and reduction in total surface area, thus more gel paste is available hence more workable.