Last updated on February 22nd, 2021

fly ash bricks
Img : srisakthiflyashbricks

Are you opting for Red bricks to construct a home? Or thinking about how wise it will be to use Fly Ash bricks to develop a structure? Today, all the reputed developers are using the latest technology to create landmark structures, and the Fly Ash Brick is helping them a lot. Fly Ash bricks are unconventional bricks manufactured from industrial wastes such as fly ash, cement, sand/stone dust.

These bricks are gaining popularity worldwide over the red bricks. Hence, you must know what these bricks are all about.

Fly ash bricks composition

fly ash bricks composition
source: Youtube

The grey-colored Fly Ash bricks are made from burning coal. This idea was first tested by Dr. Bhanumathidas and Kalidas, who also hold the same patent. The main ingredients are fly ash, water, quicklime or lime sludge, cement, aluminum powder, and gypsum. They are also 

eco-friendly as fly ash bricks are made of recycled products.

Types of fly ash bricks

Fly ash bricks are divided into 2 types- fly ash Class C and fly ash Class F.

Fly ash Class C is designated in ASTM C 618 and originates from sub-bituminous and lignite coals. Its formation consists mainly of calcium, alumina, and silica with a more moderate loss on ignition (LOI) than Class F fly ash. Fly ash Class F is assigned in ASTM C 618 and originates from anthracite and bituminous coals. It consists of alumina and silica and has a more eminent LOI than Class C fly ash. It also has lower calcium content than Class C fly ash.

Which is better? 

Both the types of fly ash bricks (Class F and Class C) are capable of making high strength concrete, but Class F fly ashes are generally more effective than Class C fly ashes in reducing the heat of hydration.

Fly ash bricks advantages

These bricks are light in weight, and their strength improves with time. These bricks’ uniform size gives an impeccable structure that the red bricks hardly offer. The Fly Ash Bricks are environment-friendly as they are made from coal-burning and create a sound-proof environment.

The Fly Ash bricks are a self-cementing product and do not need soaking in water before use. Also, the production of these bricks is cost-efficient. Thus, developers worldwide and even India are using Fly Ash bricks instead of the regular red bricks that create pollution. Simultaneously, the production process doesn’t have a uniform size as they get damaged while transferring from one place to another.

The fly ash bricks’ robust nature makes them earthquake-resistant and deals with natural calamities like hurricanes and even fires. These bricks have high fire insulation, and the uniform size of these bricks reduces the plaster requirement by 50 percent.

The Gypsum plaster can also be done directly on the Fly Ash bricks without lime plaster. The minimum water penetration restricts seepage of water and offers a subtle finish to the structure.

The Fly Ash bricks blend finely with alkalis of cement and make a resistant structure. Also, the pozzolanic reaction between lime and fly ash produces less heat and restricts thermal cracking.

Fly ash bricks vs. red bricks

fly ash bricks composition
source: Engineering Discoveries
  • To protect our environment, utilizing fly ash bricks would be helpful as they are eco-friendly.
  • Fly ash bricks have a more uniform shape than cast in machine mould.
  • Fly ash bricks are less expensive and light in weight than red bricks. Therefore, it helps to reduce construction cost.
  • When fly ash bricks are made with high automated machines, these bricks’ finish does not need plastering.

All in all, Fly ash bricks score over red bricks on Environment friendliness, the cost of production, technical parameters, and price. Fly Ash bricks the best product to use for construction purposes at a reduced cost.