AAC (Autoclaved Aerated Concrete) blocks are manufactured through a process that involves a combination of raw materials, mixing, molding, curing, and autoclaving. Here's a step-by-step overview of how AAC blocks are made:
Raw Materials Preparation:
OPC (Ordinary Portland Cement) is used as the binding agent.
Quicklime is used to create gas bubbles in the AAC mixture.
A fine, powder-like byproduct from coal-fired power plants, it reacts with lime to form gas during autoclaving.
Silica sand is the main aggregate that provides structure and strength to the blocks.
Provides the necessary moisture for the chemical reactions.
The raw materials are thoroughly mixed in precise proportions to create a slurry-like mixture. Aluminum powder is often added to the mixture as a foaming agent.
The mixed slurry is poured into molds of desired sizes and shapes. The aluminum powder reacts with lime and releases hydrogen gas, which creates bubbles in the mixture, resulting in a cellular structure.
Rising and Pre-Curing:
The molds are kept undisturbed for a few hours, allowing the mixture to rise and solidify slightly. This pre-curing phase initiates the formation of the cellular structure.
After pre-curing, the molds are loaded into an autoclave, which is a pressurized chamber. The autoclaving process subjects the blocks to high-pressure steam and temperature, causing a chemical reaction between lime, fly ash, and aluminum powder. This reaction generates additional gas, expanding the bubbles in the mixture, resulting in the characteristic lightweight and porous structure of AAC blocks. The autoclaving process also enhances the physical properties of the blocks, such as strength and durability.
Cooling and Demolding:
Once autoclaving is complete, the blocks are gradually cooled within the autoclave. After cooling, the blocks are removed from the molds.
Cutting and Finishing:
The large blocks are then cut into desired sizes using specialized cutting machines. These cut blocks can have various dimensions, such as standard blocks, lintel blocks, corner blocks, etc.
The freshly cut blocks undergo a secondary curing process, which allows them to attain their final strength and durability over a period of a few days.
Throughout the manufacturing process, quality control checks are conducted to ensure that the blocks meet required standards in terms of dimensions, density, strength, and other physical properties.
Please note that above following description outlines the process of manufacturing AAC (Autoclaved Aerated Concrete) blocks for educational purposes only. This content is not intended to serve as operational instructions or professional guidance for actual manufacturing. Attempting to manufacture AAC blocks without proper expertise and adherence to industry standards can pose risks and hazards.Its for education purpose only