Characteristics - Aerated Lightweight Concrete Block

Aerated Block

Advantages of Aerated Lightweight Concrete Bricks - AAC and ALC/NAAC

Lightweight -
• Steel & Cement requirement in structure is less due to less weight of wall construction results in savings
up to 15% of total project cost.
• Facilitates construction of unplanned walls anywhere & anytime.
• Three times less weight than clay or fly ash bricks and Blocks have an average compressive strength >2.5 N/mm2
Fire resistance -
• Thermal insulation performance is 5 times better than clay bricks & 10 times better than RCC
• With a just 100 mm thickness of wall 700kg/m3, aerated lightweight concrete Bricks offers fire endurance for heat transmission for Long hours without releasing any toxic fumes.
Weather & Earthquake resistance -
• Water absorption of aerated lightweight brick is relatively lower than any other materials. It is < 20 % for a density of 700 kg/m3.
• Closed cell structure of aerated lightweight concrete bricks reduces water absorption, So, No more Damp spots on the wall.
• Lower water absorption property of these blocks will help to reduce cracks in walls
• The lightness of the material increases resistance against earthquake
Sound Insulation -
• Due to porous structure, it gives very better sound insulation
• It is ideal in construction of schools, hospitals, amphitheaters. Etc.
Energy Savings –
• Less Electricity for AC/Heater. Due to Good thermal Insulation Property.
• Pollution free. Least energy requirement on production.

Environment Friendly -
• aerated lightweight concrete bricks are manufactured with fly ash - 100% recycled resource.
• Valuable Soil is not consumed.
• Very Less energy used for manufacturing.

Longer Life -
• Compressive strength increases with age of ALC/NAAC Blocks
• Typical Life is approximately double than clay bricks
Money Savings -
• Economical in transportation, reduction in Manpower. Due to less weight & larger size
• Significant reduction of overall weight results in savings on structural frames, footings or piles (steel and cement).
Such savings are often the multiple of the actual cost of the material itself.
• Decrease in number of joints and accurate dimensions of blocks, reduces cement mortar, plastering and precious
time & cost of labor.
• The bricks can be sawed, drilled and shaped like wood using standard hand tools, regular screws and nails.
It is simpler than brick or concrete. so less wastage.
• By using 6 inch block in place of 9 inch brick, customer gets an additional 2% - 3% carpet area. The savings on
account of additional carpet area gained is more than cost of bricks
• Savings in construction cost can be as much as up to 15% when using aerated lightweight concrete blocks, as
compared to clay bricks after considering resulting saving in steel, structure, cement, sand, gravel, etc


Difference Between AAC and ALC/NAAC Blocks
Block manufacturing process up to cutting is Similar in both AAC and ALC/NAAC. Only difference is curing type. Any ALC plant can be upgraded to AAC in future by adding Autoclave and Boiler
What is AAC ( Autoclaved Aerated Concrete ) Block : This is cured in pressurized Steam ( Typically 12KG Pressure / 190°C Temperature ). Due to pressure and temperature, block achieves it full strength in Approximate 12 Hour's curing.. Here strength of blocks is fixed after curing, There's NO change in strength in the future.
Generally this method is used for higher capacity plants.

Plant cost is very high compared to water curing plant - Example - 16M3/Day AAC machinery cost is approximate - Rs. 80 Lac
What is ALC ( Aerated Lightweight Concrete ) / NAAC ( Non AAC ) Block : This is cured with water , Just like we cure normal concrete by sprinkling water and keeping concrete wet. Here block gets full strength after 28 Days. But we can ship and utilize product after 10 Days. ( Curing process consumes water inside block which we used while mixing ). Strength of block gains day by day.
This method is used for small capacity plants up to 80M3/Day

Plant cost is very Less Compared to AAC plant - Example - 17M3/Day ALC Plant Machinery cost is approximate - Rs. 20 Lac
Technical Characteristics    
Density 600-750 600-800
Compressive Strength 30-45kg/CM² 25-40kg/CM² - After 28 days
Change in strength in future No change in strength Gain in strength day by day
Block ready for use Next day after manufactured After 10 days after manufactured
Water Absorption 20-24% Depend on density 12-20% Depend on density
Manufacturing Process    
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 12Hrs 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 Medium/Low
Maintenance Higher Lesser
Pollution while Production Yes No
Government formalities, permissions Strict norms, IBR approval required, yearly
Easy permissions as there's No pollution.
Basic Machine Cost without Taxes Very High
( 16M3 Plant basic machinery cost is approximate Rs. 80 Lac )
( 17M3 Plant basic machinery cost is approximate Rs. 20 Lac )
Overall investment High Approximate 25% compared to AAC
Profit Per Brick Almost similar to ALC/NAAC Almost similar to AAC
ROI period* 48-72 Months 12-24 Months
AAC Plants ALC / NAAC Plants Dry mix Plants

*ROI is depend on various factors such as machine model, automation level, raw material cost, finished product sales price, business manners.
All above figures are for information only. actual may differ from place to place. we suggest our clients to study all the factors before starting the project.