What is the best way to build a house - from autoclave (AAC) or non-autoclaved aerated (ALC) concrete? Are there any significant differences between the materials? Which is better: autoclaved or non-autoclaved aerated concrete? We answer all questions as fully and honestly as possible. We compare in detail autoclaved and non-autoclave blocks for all characteristics.
Let’s compare …
Autoclaved (AAC) and non-autoclaved aerated (ALC) concrete are two very similar materials. They are varieties of aerated (cellular) concrete. This group of materials also includes foam concrete (CLC) . Aerated concrete is a type of lightweight concrete, the weight of which is reduced due to the content of air pores. Pores are formed as a result of various chemical processes:
Hardening of autoclaved concrete occurs in autoclaves at high temperature and pressure (about 190 °C and 12Kg), it achieves its desired strength in12 Hours curing. Strength of concrete will not gain in the future.
For hardening of non-autoclaved aerated concrete, a temperature of 35-40 ° C is sufficient, it hardens under natural conditions. Just like we cure normal concrete by sprinkling water and keeping concrete wet. This concrete gets the desired strength after 28 Days. But we can ship and utilize the product after 10 Days. ( Curing process consumes water inside the block which we added while mixing ). Strength of concrete gains day by day.
Also One can start with Non autoclaved concrete block factory and if required it can be converted later to AAC by adding autoclave and boiler. This can be a HYBRID production line as it can produce AAC as well as ALC simultaneously
Compressive strength of both autoclaved and non autoclaved concrete is almost equal. Strength can be varied by changing the quantity of cementitious material in the mix. Adding more cement will result in stronger concrete with higher production cost.
Strength of autoclaved concrete is unchanged with time. Where non autoclaved blocks gain strength with time
Autoclaved concrete blocks absorb more water compared to non autoclaved concrete blocks
Autoclaved concrete blocks can be utilized after 3 Days of manufacturing. Where non autoclaved blocks can be utilized only after 10 Days.
One of the properties of autoclaved aerated concrete is its fragility. Non-autoclaved aerated concrete is significantly less brittle.
Autoclaved and non autoclaved concrete blocks look similar. There's no visual difference between both. Even dimensional accuracy for both is similar.
| Differentiate between | Autoclaved Concrete (AAC) | Non-autoclaved Concrete (ALC / NAAC) |
|---|---|---|
| Density | 600-750 Kg/M³ | 600-800 Kg/M³ |
| Compressive Strength | 30-45 Kg/cm² | 25-40 Kg/cm² After 28 days |
| Change in strength in future | No change in strength | Gain in strength day by day |
| Block ready for utilize | 3 days after manufacturing | 10 days after manufacturing |
| Water Absorption | 20-24% Depend on density | 12-20% Depend on density |
| Delicacy of material | Fragile | Less brittle |
| Raw Material | Water, Cement, Quick Lime, Gypsum, Fly ash, Aluminum Powder, Coal/Wood ( For Steam ) | Water, Cement, Quick Lime, Gypsum, Fly ash, Aluminum Powder, Hardener |
| Curing Type | Pressurize Steam | Natural (Water) Curing |
| Curing Period | Approximate 12 Hrs | Minimum 7 Days |
| Machinery Required | Mixer / Cutter / Molds / Boiler / Autoclave | Mixer / Cutter / Molds |
| Production Capacity | 10M3/Day to 500M3/Day | 3.3M3/Day to 80M3/Day |
| Land Requirement | Minimum 30000 FT² for Smallest plant | Minimum 6000 FT² for Smallest Plant |
| Electric Load | 50HP for Smallest plant | 5HP for Smallest plant |
| Operator skill | High | Less compared to AAC |
| Maintenance | Higher | Lesser |
| Pollution while Production | Yes | No |
| Government formalities, permissions | Strict norms, IBR approval required, yearly renewal | Easy permissions as there's almost Zero pollution. |
| Basic Machine Cost without Taxes | Very High ( 16M3 Plant basic machinery cost starts from approximate Rs. 80 Lac ) | Less ( 17M3 Plant basic machinery cost starts from approximate Rs. 20 Lac ) |
| Overall investment | High | Approximate 25% compared to AAC |
| Profit Per Brick | Almost similar to ALC/NAAC | Almost similar to AAC |
Almost all negative reviews about non-autoclaved aerated concrete arise due to unscrupulous artisanal manufacturers. Non-autoclaved aerated concrete made on high-quality factory equipment is almost similar in characteristics, but in some ways even surpasses others, and, importantly, is cheaper to produce with cheaper equipment.
We "Essarcon" already helped to launch More than 55 of aerated concrete plants and we know what issues concern beginner businessmen. We have collected a few useful tips for those who are going to build their business on aerated concrete from scratch. What you need to pay attention to and what mistakes you can avoid.
We offer top-notch products along with prompt services that guarantee customer satisfaction. Whether you're a small business owner or a large industrial corporation, we have the perfect machine for you.
The warranty for the equipment is 1 Year, but even if you call us in 10-15 years, we will certainly help you.
By purchasing equipment from us, you will receive every possible help from a team of Essarcon employees as a bonus.