Question

How much percent of fly ash is, mixed with Portland cement?

(a) 10 to 25%

(b) 5 to 10%

(c) 30 to 50%

(d) 50%

I have been asked this question in examination.

I need to ask this question from Ash and its Effects on Boiler Operation and Performance in chapter Steam Generators & Accessories of Energy Engineering

Answer 1

Correct option is (a) 10 to 25%

To elaborate: 10 to 25% dry fly ash can be used as during manufacture of cement or blended with finished Portland cement to produce Portland pozzolana cement whose strength is higher. The major drawback of this cement is its high cost and it requires more setting time.