Introduction

AAC blocks stands for Autoclaved Aerated Cement blocks. These are lightweight, durable, eco-friendly and heavy load-bearing construction materials. Due to these features, AAC blocks have started gaining preference over traditional clay bricks in countries like India, the United States, Australia, South Africa, Canada and Britain. AAC blocks have higher compressive strength than clay bricks and are about 8 to 9 times bigger in size.

How are AAC blocks made?

AAC blocks are made using portland cement, gypsum, sand, aluminium powder and water and are prepared through baking under high temperature and pressure in an autoclave. It is coated with a stucco finish like veneer brick or vinyl siding.

Advantages of AAC blocks

With the world becoming more environmentally conscious and growing technological advancements, there has been an increase in the demand for the usage of eco-friendly construction materials. And that is where AAC blocks come into play. Given below are advantages of the usage of the AAC blocks.

AAC blocks reduce the deadweight. It reduces steel, mortar and cement consumption due to its lighter weight. Also, the lightweight blocks are easier to transport and there is a reduction in the shipping and logistics costs as well.

AAC blocks are baked using a non-polluting process. There is a decrease of 50% in greenhouse gas emissions when manufacturing AAC blocks compared to traditional bricks. Some of the offcuts can also be recycled or used as aggregates.

AAC blocks are about 50% lighter and 10 times larger than traditional bricks, easier to install and more flexible. As they have fewer joints and their dimensions are consistent, the laying process is easier. There is a reduction in the construction time by 25%. The blocks also provide high compressive strength, about 3-5 N/mm².

AAC blocks reduce the overall operating cost by 30%-40%. With the reduction in the number of joints and the quantity of cement and steel, the construction cost is also reduced by 2.5%. Additionally, high insulation blocks can save up to 30% in energy costs.

AAC blocks provide high precision in terms of size. These are available in the exact dimensions that help in giving a smooth finish to the wall with a perfect joint between different elements.

AAC blocks are fire-resistant, soundproof, earthquake-resistant, moisture-proof, pest resistant and provide thermal insulation. Along with that, AAC blocks provide great ventilation and energy efficiency.

Disadvantages of AAC blocks

AAC blocks have a lot of positives, but that doesn’t mean they don’t possess any flaws. Given below are some of the disadvantages of using AAC blocks.

1. There is a possibility of crack formations in the wall after the installation of AAC blocks. This can be prevented by using suitable adhesives instead of cement mortar for masonry.
2. As AAC blocks are non-load-bearing materials, these can be used only for partition walls.
3. AAC blocks are brittle, thus requiring more care than clay bricks during transportation.
4. In the case of fixing furniture on the wall, you cannot use nails. You have to use a drill bit and insert a raw plug. 
5. A lot of contractors are unaware of AAC blocks, and they employ unskilled masons as the mortar used is thin as compared to conventional cement-based mortar.

Now that you are aware of the advantages and disadvantage of AAC blocks, you can decide which type of brick to use for your construction, based on your needs.