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 content of 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
Statement 1 is correct: Fly ash finds various applications in construction, including brick manufacturing. Its pozzolanic properties improve the strength and durability of bricks.
Statement 2 is correct: Fly ash can partially replace Portland cement in concrete mixes. It reacts with the hydration byproducts of cement to form additional cementitious materials, leading to benefits like improved workability, reduced heat of hydration, and enhanced concrete performance.
Statement 3 is incorrect: Fly ash primarily consists of silicon dioxide (SiO2), aluminum oxide (Al2O3), and calcium oxide (CaO). However, it may also contain trace amounts of heavy metals like arsenic, mercury, and chromium.