What is AAC Block? (Autoclaved aerated concrete)

AAC Blocks: Autoclaved Aerated Concrete is a Lightweight, Load- bearing, High- insulating, durable building products. This blocks which is produced in a wide range of size and strengths.

They are solid blocks which are stacked and bonded together with mortar and can be reinforcedwith steel and other things to make a good amount of strength. ACC structure are very airtight which helps reducing the loss of energy due to air leaks.

aac blocks

These blocks are three times lighter than normal blocks concrete, it is a certified green building material which has great uses and is widely used for commercial, industrial and residential construction. The property of being porous, non-toxic, reusable, and renewable and recycle make its demand even larger.

This material was developed in the 1924 in Sweden. Now at this position this building block used in almost every construction. The ingredient for the formation of this building block is sand, cement, water and a bit of rising agent.

Advantages of ACC

  • Acc- Autoclaved aerated concrete, they are lightweight, Cellular, porous concrete blocks.
  • They have very Easy Usability, they are easy to cut, frown, drilled, chiselled, nailed and can be shaped in an accurate proportion with ease.
  • Thermal conductivity: Acc block provide a great thermal conductivity which give your house a comfortable interior.
  • Free Resistant Bricks.
  • One of the best characteristics they are eco-friendly since they are made from fly ash, they can reused, renewable and recyclable. Renewable and recyclable.
  • The best thing about this blocks are that they are cost efficient.
  • Acc helps in reducing noise pollution and also helps in making fresh the indoor air quality. There are many air cells available in it. Which helps in dampen the sound transmission and in addition to this ACC has low infiltration which helps improving indoor air quality.
  • ACC has both structural and insulation materials which helps cutting out the need of other insulation material.

Features of AAC 

  • ACC doesn’tcontain any kind of toxic materials.
  • ACC Blocks have an attractiveappearance. You can build them in the way you.
  • They have high compressive strength, they are 25 % stronger than other products
  • One of the best in class facilityof this blocks is that they results into higher steadiness. They can withstand very the impact of earthquake.
  • ACC are sound proof, since they have porous structure, the sound transmission class rating of the ACC blocks is around 45db.
  • Acc requires very less maintenance. And even helps in reducing the maintenance cost to 20 to 30 % and one of the best benefit of ACC is thatyou can make variety of size blocks which helps in increasing the carpet area.
  • They have a very accurate size which helps reducing the use of cement and steel usage. Due to variety in sizes this make the walls very smooth and you can make perfect

Manufacturing process

  • This product is a manufactured by pulverised by fly ash, cement, lime, water and an aeration agent. The first step is to take aluminium is poured into the mould. And then concrete is added to the aluminium. Then the aluminium reacts with lime and fly ash, which results in the formation
  • The hydrogen bubbles cause the concrete to expand which doubles the time of its original volume, now hydrogen is made to evaporate. Which make the cell aerated concrete which is then cut into the block and then steam and pressure-cured in an autoclave.


  • ACC is used in both interior as well as exteriorconstruction.
  • ACC is very easy to install hence in is used in high-rise buildings.
  • ACC reduce the use of mortar since number of joint are reduced to a great extent.
  • They are used in the formation of cannels and drainagesystem formation due to its water resistant property.


  1. The density (PCF) of this concrete is around 25-50.
  2. The compressive strength of this concrete in PSI is between 360-1090.
  3. The fire rating is less than or is around 8.
  4. The thermal conductivity comes around 0.75-1.20.

 This concrete no doubt has some of the best in class features but has somedrawbacks also

  1. They don’t have consistency in quality and colour.
  2. The cost of this concrete is higher than the normal cement.
  3. You need to add exterior cladding to protect the walls from weather
  4. This concrete has low R value.

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