Aerated concrete blocks, also known as autoclaved aerated concrete (AAC) blocks, are lightweight and porous blocks that are widely used in the construction industry for walls, floors, and roofs. They are made from a mixture of cement, lime, sand, gypsum, and aluminum powder, which creates a chemical reaction that forms gas bubbles in the mixture, resulting in a lightweight, cellular material.

Special masonry mortar and plastering mortar are used for aerated concrete blocks for several reasons:

1. Adhesion: Aerated concrete blocks have a porous surface that requires a specialized mortar that can bond well to the block’s surface. The special mortar has a high adhesive strength and can form a strong bond with the blocks, ensuring a secure and durable structure.
2. Water absorption: Aerated concrete blocks have a high level of water absorption, and regular mortar may not be able to withstand the absorption and drainage of water. Special masonry mortar and plastering mortar have low water absorption and high water retention capacity, ensuring that the blocks remain strong and durable, even when exposed to moisture.
3. Workability: Specialized masonry and plastering mortar have excellent workability, which allows the mortar to be applied easily and smoothly to the blocks. The mortar can be spread evenly on the blocks’ surface, ensuring a level and uniform finish.
4. Thermal insulation: Aerated concrete blocks have excellent thermal insulation properties, which can be enhanced by using specialized mortar. The mortar can be mixed with insulating materials, such as expanded perlite or vermiculite, to improve the blocks’ insulation properties.
5. Crack resistance: Specialized masonry and plastering mortar have a high level of crack resistance, which is essential for ensuring the long-term durability and structural integrity of the building. The mortar can withstand movement and vibrations caused by environmental factors, such as earthquakes and wind.

In summary, special masonry mortar and plastering mortar are used for aerated concrete blocks to ensure adhesion, water resistance, workability, thermal insulation, and crack resistance. Using the appropriate mortar ensures the long-term durability and structural integrity of the building, providing a safe and comfortable living environment for occupants.