Question

With reference to 'fly ash' produced by the power plants using coal as fuel, which of the following statements is/are correct? 

1. Fly ash can be used in the production of bricks for building construction. 

2. Fly ash can be used as a replacement for some of the Portland cement concrete. 

3. Fly ash is made up of silicon dioxide and calcium oxide only, and does not contain any toxic elements. 

Select the correct answer using the code given below. 

(a) 1 and 2 (b) 2 only (c) 1 and 3 (d) 3 only

Answer 1

(a) Fly ash brick (FAB) is a building material, specifically masonry units, containing class C fly ash and water. All fly ash includes substantial amounts of silicon dioxide (SiO₂) aluminum oxide (Al₂O₃) and calcium oxide (CaO), the main mineral compunds in coal-bearing rock strata. Fly ash can be used as a replacement for some of the Portland cement contents of concrete.