1. Appearance
The appearance of fly ash bricks is very attractive due to their pleasing colors like cement, uniform size, and smooth finish. Due to uniform size, mortar required for walls and plastering reduces almost by 40-50%.
Plaster of Paris (Gypsum plaster), putty can be applied directly without a baking coat of plaster. These bricks are free from cracks, wrap age, organic matter, pebbles, and nodules of free lime.
2. Strength
The compressive strength of fly ash bricks is very high (9-10 N/mm2). Due to high strength, no breakages/wastages during transport and handling. The lower thickness of joints and plaster reduces cracking in plaster.
These bricks do not cause any extra load for the design of structures and provide better earthquake resistance. It improves the strength over time and offers greater strength to the building.
3. Thermal Properties
The thermal conductivity of fly ash bricks is 0.90 – 1.05 W/m2. They absorb less heat. The pozzolanic reaction between fly ash and lime produces less heat. It keeps your building cooler in summer, hence most suitable for Indian climates.
4. Durability
These bricks are highly durable and less permeable. The lower permeability can efficiently reduce the effect of fly ash bricks .
These bricks are less porous, absorb less water, and reduce dampness on the walls. It is also highly resistant to attack by mild acid, water, and sulfate.
5. Sound Insulation
Construction with these bricks provides decent sound insulation to the building.
6. Fire Resistance
These bricks are highly fire-resistant compared to normal clay bricks.
7. Sustainability
Fly ash bricks are environmentally friendly as they are made of waste materials that come from the combustion of coal in thermal power plants. There is no pollution or environmental damage, and it is considered a white category product.
8. Buildability
These bricks have easy workability and absorb less water. Unlike clay bricks, they do not require soaking in water for 24 hours. The sprinkling of water before use is sufficient. The construction technique is same as clay brick construction and does not require any extra training for the masons.
9. Availability
These bricks are generally available closer to the thermal power plants. However, finding dealers in all major cities and towns wouldn’t be a problem.
10. Cost
The same number of fly ash bricks will cover more areas than clay bricks. Consumption of mortar is also low. Requires less labour. The cost is approximately 30% lower than clay bricks.
11. Applicability
Due to their lightweight, these bricks are suitable for multi-storey structures. Less weight means less stress on the building.
These bricks can be used in load-bearing external walls in low structures, non-load bearing internal walls in low/mid structures, and non-load bearing internal or external walls in highrise buildings.
