What is fly ash?

What is fly ash?

• A. A byproduct of coal combustion in power plants, used as a supplementary cementitious material in concrete to improve strength, workability, and durability while reducing permeability and environmental impact.
• B. A type of inert filler used to reduce cost.
• C. A cement used for decorative concrete only.
• D. A curing compound applied to reduce drying shrinkage.

Answer: (A)

Fly ash is a byproduct produced when coal is burned in power plants. It’s captured from flue gases and processed into a fine powder that’s used as a supplementary cementitious material in concrete. When added, fly ash reacts with the calcium hydroxide released during cement hydration to form additional cementitious compounds, refines the pore structure, and improves long-term strength, workability, and durability. It also reduces permeability, helping protect against chemical attack and ingress of fluids. Using fly ash lowers environmental impact by reducing the amount of Portland cement needed and by recycling a waste product. It isn’t merely an inert filler, it’s an active cementitious additive. It isn’t decorative cement, and it isn’t a curing compound.

Fly ash is a byproduct produced when coal is burned in power plants. It’s captured from flue gases and processed into a fine powder that’s used as a supplementary cementitious material in concrete. When added, fly ash reacts with the calcium hydroxide released during cement hydration to form additional cementitious compounds, refines the pore structure, and improves long-term strength, workability, and durability. It also reduces permeability, helping protect against chemical attack and ingress of fluids. Using fly ash lowers environmental impact by reducing the amount of Portland cement needed and by recycling a waste product. It isn’t merely an inert filler, it’s an active cementitious additive. It isn’t decorative cement, and it isn’t a curing compound.