Bondada Ecobuild

Fly Ash Bricks

Fly ash bricks are known for their exceptional strength and durability, outlasting many traditional building materials in the industry. In this article, we will explore the properties and advantages of fly ash bricks and blocks.

What is Fly Ash?
Fly ash is a by-product derived from modern thermal power plants, produced when a mixture of air and coal dust is combusted. This finely dispersed residue results from burning ground or powdered bituminous or sub-bituminous coals, such as lignite, and is carried away by the flue gases from pulverized coal or lignite-fired boilers.

Types of Fly Ash
Fly ash is typically classified into two categories: Class C and Class F. Class F fly ash contains particles coated in what resembles molten glass, which significantly reduces the risk of expansion due to sulfate exposure, often seen in fertilized soils or coastal regions. Class F usually has a low calcium content and can contain carbon levels of less than 5%, though sometimes up to 10%.

Class C fly ash, on the other hand, is also resistant to expansion from chemical attacks but has a higher percentage of calcium oxide than Class F. It is frequently used in structural concrete and generally contains less than 2% calcium in carbon fly ash.

Properties of Fly Ash Blocks and Bricks

  • Fly ash blocks are molded into uniform shapes using poured mixtures.
  • They feature an extremely smooth surface, eliminating the need for mortar to achieve a polished finish.
  • Fly ash blocks are lightweight, making them less bulky compared to traditional clay blocks.
  • Fly ash concrete is highly resistant to corrosive elements and sulfate attacks.
  • The shrinkage of concrete made with fly ash is minimal, enhancing durability and performance.

Advantages of Fly Ash Blocks and Bricks

  • The lightweight nature of fly ash bricks makes them ideal for multi-story buildings, reducing the stresses and strains on foundations as building height increases.
  • Construction with fly ash bricks requires less mortar, which translates to reduced labor costs during installation.
  • Utilizing fly ash is environmentally friendly, as it repurposes industrial waste into high-quality building materials.
  • The small particle size of fly ash contributes to denser concrete, decreasing permeability and enhancing structural strength.
  • Fly ash bricks absorb less heat, making them more suitable for hot climates, such as those in India, compared to clay bricks.
  • The concrete mix generates a low heat of hydration, preventing thermal cracking.
  • Fly ash concrete exhibits resistance to acids and sulfates, ensuring long-term durability.
  • Due to their high strength, fly ash bricks are less likely to break during transportation and installation.
  • Water penetration is significantly reduced, minimizing the risk of leakage through fly ash bricks.
  • Fly ash bricks boast high compressive strength and low porosity, leading to reduced water absorption and overall cost savings.
  • The production of fly ash bricks does not require fossil fuels, resulting in negligible greenhouse gas emissions.

Bondada is dedicated to advancing green technology within the construction industry. We have perfected the art of producing bricks and manufacturing AAC blocks using 70-80% fly ash.