In order to prevent Alkali-aggregate reaction, low alkali cement can be used, in such a case what is the maximum permissible percentage of fly ash allowed in concrete mix design?
- A10%
- B20%Correct
- C30%
- D40%
Solution
Concept
Fly ash with low alkali cement
Step-by-step solution
1. The key gives 20% fly ash as the permissible level.
Explanation
Fly ash reduces the alkalinity of the pore solution.
Why the other options are wrong
Other values are not the key.
Correct answer: B) 20%