Correct Option
Fly ash is a fine powder byproduct generated from the combustion of pulverized coal in thermal power plants. It possesses pozzolanic properties, making it valuable in various applications.
- Statement 1 is correct. Fly ash is extensively utilized in the manufacturing of bricks for building construction. These fly ash bricks are known for their strength, uniformity, and reduced environmental impact compared to traditional clay bricks.
- Statement 2 is correct. Fly ash serves as a pozzolanic material and can partially replace Portland cement in concrete mixtures. Its inclusion enhances the workability, strength, and long-term durability of concrete, while also contributing to a reduction in the carbon footprint associated with cement production.
Incorrect Options
- Statement 3 is incorrect. While fly ash primarily consists of silicon dioxide (SiO₂) and calcium oxide (CaO), it also contains other major oxides such as aluminium oxide (Al₂O₃) and iron oxide (Fe₂O₃). Furthermore, depending on the source of coal, fly ash can contain various toxic trace elements, including but not limited to arsenic, mercury, and lead. Therefore, the assertion that it contains only silicon dioxide and calcium oxide and no toxic elements is factually inaccurate.
- Options (b), (c), and (d) are incorrect as they either omit a correct statement (Statement 1) or include the factually inaccurate Statement 3.