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 contents 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 codes given below.
✓ Correct answer: a) 1 and 2
ExplanationFly ash is a fine powder produced as a byproduct of burning pulverized coal in thermal power plants.It is collected from the flue gases through electrostatic precipitators or bag filters before the gases are released into the atmosphere.Fly ash is composed of small, glassy, spherical particles and is categorized as an industrial waste material.Statements 1 is correct: Fly ash is utilized in manufacturing bricks, known as fly ash bricks, which are used in building construction.These bricks offer advantages such as uniformity, reduced weight, and enhanced strength compared to traditional clay bricks.Statements 2 is correct: Fly ash is commonly used as a supplementary cementitious material in concrete.It can replace a portion of Portland cement, leading to benefits like improved workability, reduced heat of hydration, and increased long-term strength.Additionally, incorporating fly ash contributes to sustainability by recycling industrial waste and reducing greenhouse gas emissions associated with cement production.Statement 3 is incorrect: While fly ash primarily consists of si
Practice more Science PYQs
Attempt a free 10-question quiz or browse the full Science & Technology previous-year-question bank with instant answers and explanations.
🔬 Science PYQs →