The history of AAC block: From invention to modern construction

What is an AAC block?

AAC (autoclaved aerated concrete) blocks are building materials custom for wall and partition construction. They are made from cement, lime, sand or fly ash, water, and aluminum powder. The aluminum creates tiny air bubbles, causing the mixture to rise like a cake. Once set, it's cut into blocks and cured in a high-pressure steam chamber called an autoclave, giving it strength, lightness and insulation properties.

Early Invention of Autoclaved Aerated Concrete (AAC) Blocks

• 1880: German scientist Michaelis patents steam curing of concrete, starting the aerated concrete concept.
• 1889: Czech inventor Hoffman patents a method to make concrete porous using carbon dioxide.
• 1914: American inventors Aylsworth and Dyer create porous concrete using aluminum powder and calcium hydroxide.
• 1920: Swedish architect Dr. Johan Axel Eriksson and Professor Henrik Kreuger developed improved aerated concrete.
• 1924: Dr. Eriksson patents a method using limestone and ground slate—foundation for the first commercial AAC block production.

WHY WAS AAC BLOCK INVENTED? — An in-depth look

• Resource and Energy Efficiency: The early 20th century also saw concerns about resource scarcity and industrial waste. AAC production uses less raw material per cubic meter and can incorporate by-products like fly ash, making it a more sustainable choice. Additionally, the autoclaving process cures the material faster and at lower temperatures compared to traditional concrete curing.
• Innovative Chemistry: The breakthrough chemical process—introducing aluminum powder to generate hydrogen gas and create a uniform porous structure—enabled the production of strong, lightweight blocks with excellent insulation.
• Minimizing Negative Environmental Impact: Importantly, the inventors recognized the need for a building material that would reduce the disturbance of valuable agricultural land. Traditional clay bricks required large amounts of fertile soil and involved harmful kiln emissions. This reflected an early environmental consciousness, developing a material that would have a positive impact on the environment by lowering carbon emissions and conserving natural resources.

Why it’s high time to invest in AAC industry!

• High Growth Potential: Bangladesh is on the verge of a construction boom, driven by urban expansion, infrastructure projects, and industrial development.
• Open Market Advantage: With traditional brick kiln licensing restricted, AAC stands as the clear alternative, creating a massive supply gap ready to be filled.
• Government-Backed Industry: AAC is officially recognized under the national green construction agenda, ensuring long-term policy support.
• Economical Production: Requires less energy, fewer workers, and recycles industrial waste, making it cost-effective from the ground up.
• Tax-Free Profits: Enjoy VAT-free sales on AAC blocks, boosting margins and accelerating ROI (return on investment).
• Low Carbon Footprint: AAC production emits significantly less carbon, contributing to climate change mitigation.
• Future-Smart Business: As sustainability becomes non-negotiable, AAC aligns perfectly with global and national environmental goals.

So, the AAC industry in Bangladesh isn’t just an opportunity today—it’s a strategic move for any visionary investor.

FAQs regarding AAC block