Introduction
Fly ash bricks are modern, high-quality bricks that contain class C or class F fly ash and water. Class C fly ash is a type of fly ash specified in ASTM C 618, which is a standard specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for use in concrete. It originates from sub-bituminous and lignite coals and its composition consists mainly of calcium, alumina, and silica. Class F fly ash is designated in ASTM C 618, and it originates from anthracite and bituminous coals. It consists mainly of alumina and silica and has a higher Loss on Ignition than Class C fly ash. It also has a lower calcium content than Class C fly ash.
Fly ash bricks are used to replace standard clay bricks and have superior qualities to the conventional ones. Its utilization also results in the conservation of natural resources as well as the protection of the environment.
The Raw Materials Used for the Preparation of Fly Ash Bricks
A possible material mix for the production of Fly ash brick is as follows-
| Material | Mass |
| Fly ash | 60% |
| Sand/ Stone dust | 30% |
| Portland Cement or Lime | 10% |
The main components of Fly ash bricks are fly ash, water, quicklime or lime sludge, cement, aluminum powder, and gypsum. During the preparation of the bricks, the method of autoclaving is applied as it encourages cement to cure more quickly, resulting in the increase of the block’s toughness. Also, gypsum serves as a long-term enhancer of strength. The aluminum paste causes a chemical reaction that gives AAC its distinctive porous structure, low weight, and insulating qualities.
It differs from other lightweight concrete materials due to the aforementioned characteristics. With identical strengths, the ultimate product is a lighter block that weighs less than 40% as little as traditional bricks. The specific gravity remains within the range of 0.6 to 0.65. By using these blocks, one can use less structural steel and concrete (about 30 to 35 percent less dead load) in buildings.
Commercial operations can be divided into two groups: those using lime and those using cement (OPC), where the latter serves as a source of lime. Fly ash (50 percent), slaked lime (30 percent), and anhydrous gypsum (20 percent) make up the composition of the lime route to which three to four times as much stone dust, and sand, or any other inert filler material may also be added. In the cement route, the composition is Fly ash (76 percent), OPC (20 percent), and anhydrite (4 percent) to which three to four times as much filler material may be added.
Conclusion
Over the years, Fly ash bricks have gained immense popularity and a large section of people can be seen opting for them over clay bricks. As they provide a lot of advantages, they are highly used for construction purposes, helping build high-quality structures with outstanding strength, while being environment-friendly too.
About Us
TNE AAC Private Ltd. is one of the most important mercantile companies in the North Eastern Region. The company provides superior-quality AAC blocks under the name Taj AAC Blocks. In addition, the manufacturing facilities of the company have been developed in Changsari and Kamrup (local).
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