What is AAC?
Autoclaved Aerated Concrete (AAC) is a lightweight, precast, foam concrete building material suitable for producing concrete masonry unit (CMU) like blocks. Composed of quartz sand, calcined gypsum, lime, cement, water and aluminum powder, AAC products are cured under heat and pressure in an autoclave.
The aluminum powder serves as a blowing agent that causes the fresh mixture to rise like bread dough, giving the material its characteristic cellular structure with evenly distributed voids.
Manufacturing Process
Mixing
Raw materials are precisely measured and mixed with water to form a slurry
Casting
The mixture is poured into molds where aluminum powder creates cellular structure
Pre-curing
The green cake is allowed to set and gain initial strength before cutting
Autoclaving
Blocks are steam-cured under high pressure and temperature for 8-12 hours
Technical Properties
Physical Properties
Performance Benefits
Applications
Residential Buildings
- • Load bearing walls
- • Partition walls
- • Boundary walls
- • Individual houses
Commercial Buildings
- • Office complexes
- • Shopping malls
- • Hotels and resorts
- • Educational institutions
Industrial Applications
- • Warehouses
- • Factory buildings
- • Cold storage units
- • Industrial sheds
Standards & Certifications
Indian Standards
- • IS 2185 (Part 3): 1984 - Concrete Masonry Units
- • IS 6042: 1969 - Autoclaved Cellular Concrete
- • ISI License No: HYBO/CM/L6300090807
- • Grade-1 Quality Certification
International Standards
- • ASTM C1386 - Standard Specification for AAC
- • EN 771-4 - European Standard for AAC Units
- • ISO 9001:2015 Quality Management
- • Green Building Council Approved
Comparative Analysis
Technical Parameters
| Parameters | Traditional Red Brick | AAC Block |
|---|---|---|
| Size (In mm) | 225 x 100 x 65 230 x 75 x 115 | 600 x 200 x (100/150/200/225) 4"/6"/8"/9" |
| Precision in Size | 5 to 10 mm (+/-) | 1.5 mm (+/-) |
| Compressive Strength | 2.5 - 3 N/mm² | Above 3.8-5.0 N/mm² |
| Density | 1800-2000 kg/m³ | 550-650 kg/m³ |
| Fire Resistance | Approx. 2 hrs | 2 - 7 hrs depending on thickness |
| Energy Saving | Less | Reduces usage of air conditioner. 25-30% less electricity consumption |
| Thermal Conductivity | K value = 0.81 W/mk | K value = 0.16 W/mk |
| Sound Insulation | More than 50db for 230mm thick wall | 45-45db for 200mm thick wall |
| Mortar consumption per M³ with 1:6 | 1.40 bag of cement | 0.50 bag of cement |
Consumer Parameters
| Parameters | Traditional Red Brick | AAC Block |
|---|---|---|
| Quality | Normally varies | Uniform and finished |
| Environmental Benefits | One clay brick consumes 3kgs of soil | No soil used, uses fly ash from thermal plants |
| Maintenance | High | Less due to superior properties |
| Pest & Termite Resistance | Low | AAC blocks are inorganic, insect resistant and solid wall construction material. Termites and ants do not eat or nest in AAC blocks |
| Wastage during construction | 10-15% | 1-2% wastage and can be cut with an axle blade as needed |
| Construction Benefits | Low | 8 times bigger than red brick results in lesser joints, less mortar and high labour cost savings |
| Savings in plaster | No Savings | 35% reduction |
* AAC blocks clearly demonstrate superior performance across all major parameters compared to traditional red bricks