Red Bricks to Green Bricks

Going green is the only sustainable option to conserve the environment and save the planet for future generations. If you can replace the red building bricks in construction with a greener option, why not? Building bricks are the basic component of any construction project and provide strength to the foundation. A green option like aerated autoclaved concrete blocks offers a great combination of quality, strength, low weight, thermal insulation, acoustics, fire resistance and excellent build ability.

AAC blocks are made of a steam-cured mixture of sand or pulverized fuel ash, cement, lime and aeration agent. This is produced using high-pressure steam curing in autoclaves, which helps to create a physically and chemically stable product with average density being one-fifth of concrete and one-fourth of clay brick making it extremely lightweight and easy to use. AAC blocks have numerous tiny non-connecting air bubbles which make them excellent insulators. In addition, AAC is a natural non-toxic material that uses pulverized fuel ash that is a by-product of thermal power plants, making it extremely eco-friendly. If we do a quick comparison between “green” bricks and red bricks you will see that Green scores over Red on most parameters.

How does it look and weigh?

AAC blocks are grey, lightweight masonry blocks that are uniform in size while clay bricks are smaller than red blocks that are less uniform in size. Both are used for construction purposes but red bricks have been around for longer.

What goes into it?

AAC blocks are made out of a combination of pulverized fuel ash, cement, lime, gypsum and an aeration agent. On the other hand, red bricks are made from a mixture of clay, sand, lime, iron oxide and Magnesia. The quality of AAC blocks is uniform while the quality of red bricks is dependent on the quality of the topsoil used.

What can it be used for?

AAC blocks are used to build both load-bearing and non-load-bearing internal, partition and panel walls, inner part of cavity walls or as backing to brick masonry. It can also be used for external load-bearing walls and panel walls in steel or reinforced concrete frame structures.

Red bricks, being strong, hard and durable, are used as a construction material in creating buildings, arches, cornices ,pavements etc.

Where do green bricks score over red?

AAC blocks are better than red bricks in multiple ways. They are easy to handle and ordinary tools can be used for cutting them. These blocks are available in large sizes which means fewer joints, less cement and faster construction. The lightweight of the AAC blocks reduced the dead- load of the building which makes it highly earthquake-resistant. AAC blocks are made from inorganic material which makes them termite resistant, unlike red bricks. The use of AAC blocks helps to reduce the overall consumption of steel and concrete in the structure, reduce the dead load and add to the carpet area. They are easier to transport to higher floors and reduce the overall project construction time due to their larger size.

AAC blocks have another advantage over red bricks. They have a very high thermal insulation index which ensures that the ambient temperature is maintained for a longer period of time making the structure cooler in summers and warmer in winters. Research shows that AAC blocks can reduce the load on the air conditioning unit by 25% and can cut down electricity consumption on HVAC by 25-30%.

AAC blocks are roughly nine times the size of a normal red brick resulting in the reduction of 75% joints, saving mortar costs and causing minimal wastage. They need less curing leading to less water consumption which is great for the environment. In recent time, price of red bricks have shot up by 100% and thus AAC Blocks are now better priced compared to red bricks. Also the government also wants to put restriction on red bricks as it uses upper crust of soil and pollutes the environment. Hence govt has applied GST at 12% on bricks from 1 st January 2022 whereas AAC Blocks fall under 5% GST.

The lower dry density of the AAC blocks puts less load on the foundation and reduces the weight of the walls by 65%. The weight of AAC blocks is one fourth of concrete blocks & one third of red bricks. AAC blocks are extremely fire resistant and can resist fire up to 8 hours compared to red bricks which can resist only for 2 hours.

AAC blocks, being lightweight and porous have excellent acoustics properties. A 200mm thick wall can reduce 40-45 decibels of sound. AAC blocks can be used as interior partition walls as it provides a high sound reduction for privacy.

AAC blocks are made from a non-toxic material that does no harm to the environment. Usage of pulverized fuel ash helps to utilise this industrial waste generated by thermal plants. The wastage during the manufacturing process can be recycled for further use making AAC blocks the perfect green brick.

Bigbloc Construction, a company listed on National Stock Exchange, has two plants with a total capacity of 5.5 lacs cbm with plants at Umargaon near Vapi & Kapadvanj near Ahmedabad. The locational advantage helps it to cater to both Gujarat and Maharashtra markets. The company caters to large construction companies like Lodha, HDIL, L&T, Shapoorji Palloji, Runwal, PSP Projects, B G Shirke and many other reputed builders and developers.

AAC blocks need to be adopted by builders because of their eco-friendly features that can make a sustainable impact on the environment. It is a pocket-friendly alternative that reduces construction costs on one hand while reducing the carbon footprint on the other. It is high time that we moved to green bricks from red ones in our quest for eco-friendly solutions to help save the planet.

- Mohit Saboo

Director & CFO, Mohit Industries BigBloc Construction

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