It is a power point presentation on the topic of Auto-Claved Aerated Concrete Bricks(AAC). This gives a little more Knowledge about the Concrete Bricks in a Presentation format. This includes the comparison between the traditional Bricks and AAC bricks or also knows as AAC blocks, and the availability in India and use of concrete bricks for future aspects.

1. AuTOCLAVED AERATEDCONCRETE BRICKS.
Presented by- Guided By:-
VIGYAN NIDHI Mr. Vikrant Singh
Roll no. – 1428400093 (Faculty, Dept. of
Branch- Civil Engineering. Civil Engineering, UIT).
United Institute Of Technology..

2. **CONTENTS**
1. INTRODUCTION.
2. IMPORTANCE OF AAC BRICKS.
3. TYPES OF AAC BRICKS.
4. CHARACTERSTICS OF AAC BRICKS.
5. MANUFACTURING PROCESS.
6. COMPARISON BETWEEN AAC BRICKS & CLAY BRICKS.
7. COST ANALYSIS.
8. AAC BRICKS IN INDIA.
9. CONCLUSION.

3. INTRODUCTI
ON Autoclaved aerated concrete brick was invented in mid-1923 in
Sweden by a Swedish architect Dr. Johan Errikson, who was
looking for a alternate building material having quality of :-
 Wood – good thermal insulation, solid structure and easy to
work.
 Without the disadvantage of combustibility and decay.

4. Continued……..
 It is now considered as a new generation brick also known as
Autoclaved Cellular Concrete (ACC) bricks or Autoclaved Lightweight
Concrete (ALC) bricks or, autoclaved aerated concrete bricks(AAC).
 These AAC bricks are made with a mixture of cement, fly ash, lime,
aluminium and water involving an aeration process that gives it the
unique cellular structure.

5. ITS IMPORTANCE IN NEXT GENERATION CONSTRUCTION.
It seems important for the next generation construction because it involves –
 Use of waste Product:-
Fly Ash is usually a by-product of thermal power plants and is an important
raw material in the manufacture of AAC Blocks.
 Water Conservation :-
AAC blocks don’t need curing, as water used in other ordinary Clay Brick.

6. Durability:-
AAC has a very porous structure filled by Air Bubbles which arrests
water absorption into the AAC material is minimum. So, It leads to Low maintenance
and increased durability.
 Recycle / Reuse :-
 Waste from the cutting process is recycled back with raw materials and used
again.
 During construction, there is virtually no waste generated.
 AAC blocks can be reused into base preparation of roads.

7. Types Of AAC Bricks.
AAC bricks are currently available in three sizes:-
1. Infill bricks:
 Size :- 600X600 mm.
 Thickness :- 75,100,125,150,200 mm.
IMPORTANCE –
 Easily replace 60% of the concrete in roof slabs.
 Saving significant amounts of concrete, steel, labor, water, plaster etc.

8. 2. Jumbo blocks:-
 Size:- 600X200 mm.
 Thickness:- 75,100,125,150, to 200 mm.
IMPORTANCE –
 Because of large size less mortar is required.
 These bricks are more suitable for multi-storied buildings etc.

9. 3. Thermal blocks:-
 Size:- 300X200 mm.
 Thickness:- 50 mm.
IMPORTANCE –
 Delay the transmission of heat flow. So, help interiors remain warm
during winters and cool during summers.
 Good for roofing.

10. Different characteristics of AAC bricks.
The characteristics of bricks are as follows :-
1. Light-weight:
 Because of its aerated structure it become light in weight.
 The weight is only one third the density of clay bricks, makes them easy to handle
on-site.
2. Fire resistance:
 Walls of AAC bricks, with a minimum thickness of 100mm can resist fire for up to
4 hours.
 Especially for industries and companies, which are vulnerable to fire accidents,
these blocks are of much help.

11. 3. Sound insulation:
 AAC brick can minimize the sound transmission up to 42 decibels.
 Better for wall construction in hotels, auditoriums, Colleges, hospitals, etc.
4. Thermal insulation:
 The cellular structure of the AAC bricks provides excellent thermal Insulation.
 Help interiors to remain cooler during summer and warmer during winter.

12. 5. Strength and durability:
 AAC bricks made with higher weight ratio help in building stronger and
economical structure.
 They remain unaffected by the environmental conditions they ensure longer life
for the building.
6. Perfect finish and dimensional stability:
 Perfect dimensions to the blocks along with low tolerances.
 Dimensionally perfect blocks help in building uniform, thin walls with perfect
finish.

13. Steps Involved in manufacturing process.
There are mainly four steps involves in manufacturing process of AAC Bricks:-
1. Raw Material Preparation:
 Fly ash :-
 Fly ash is mixed with water to form fly ash slurry.
 Fly Ash is usually a by-product of thermal power plants and is an important raw
material in the manufacture of AAC Blocks.
 Slurry thus formed is mixed with other ingredients like lime powder, cement,
gypsum and Aluminium powder in quantities consistent with the recipe.

14.  Limestone powder:-
 Lime powder required for AAC production is obtained either by
crushing limestone to fine powder at AAC factory or by directly
purchasing it in powder form from a vendor.
Crusher for grinding lime stone.

15.  Cement :-
 53-grade Ordinary Portland Cement (OPC) from reputed manufacturer is required
for manufacturing AAC blocks.
 Gypsum :-
 Gypsum is easily available in the market and is used in powder form.
 Aluminium powder/paste :-
 A small quantity of Aluminium powder/paste is required to be added to the
mixture, it is usually weighed manually and added to the mixing unit.

16. 2. Dosing and Mixing: -
 Fly ash slurry is pumped into a separate container. Once the desired weight is
poured in, pumping is stopped.
 Lime powder, cement and gypsum are poured into individual containers using
screw conveyors.
 Mixing drum is like a giant bowl with a stirrer rotating inside to ensure proper
mixing of ingredients. Steam might also be fed to the unit to maintain
temperature in range of 40-42oC.
 Dosing and mixing process is carried out continuously because if there is a long
gap between charging and discharging of ingredients, residual mixture might start
hardening and choke up the entire unit.

17. 3. Casting and Rising : -
 Before casting, the moulds are coated with a thin layer of oil. Done in order to
ensure that cake does not stick to the mould.
 While slurry is mixed and poured into greased moulds, Aluminium reacts with
Calcium Hydroxide and water to form Hydrogen.
 Millions of tiny Hydrogen bubbles are released due to this reaction. This leads to
formation of tiny unconnected cells causing slurry mix to expand.
 These cells are the reason behind light weight and insulating properties of AAC
blocks.

18. 4. Demoulding and Cutting:-
 Once a mould is out of pre-curing room, it is lifted by a crane or rolled on tracks
for the demoulding operation.
 Cutting operation is achieved by moving green cake through horizontal cutting
machine.
 Horizontal or Vertical cuttings are made through cake using stationary steel
wires.
 These wires can be adjusted offline to get desired height of AAC blocks or panels.

19. **A Quick Comparison Between AAC Bricks and Clay Bricks**
s.no Parameters AAC Bricks Clay Bricks
1. Soil
Consumption.
Zero soil consumption. 1 square ft. of area with clay brick
walling will consume 25.5 kg of
top soil.
2. Labour. Organized sector with proper HR
practices.
Unorganized sector with rampant
use of child Labour.
3. Production
Facility.
State-of-the-art factory facility. Unhealthy working conditions due
to toxic gases.
4. Compressive
Strength.
3-4 N/m2 2.5-3 N/m2
5. Fire Resistance
(8″ wall).
Up to 7 hours. Around 2 hours.
6. Cost Benefit. Reduction in dead weight
leading to savings in steel and
concrete.
None
7. Thermal
Resistance.
Approximately 30% for heating
and cooling.
None
8. Speed of
manufacturing
HIGH LOW

20. **COST ANALYSIS**
 Cost of building materials vary from region to region.
 In Mumbai, bricks cost between Rs.6-7/- per unit.
 In Uttar Pradesh it is approx Rs. 5/- per unit.
 For Instance, one cubic meter comprises of 600 bricks, which costs around
Rs.3000-4000/- cubic meter.
 However, AAC blocks are available at the range of Rs.2800-4000/- per m3.
 Builders prefer AAC considering numerous advantages of the materials as seen
above.

21. **AAC Manufacturing in India**
The first AAC blocks plant in India was set up in early 1970s by Siporex at Pune.
S.NO. Brand Name Company Location
1. Aerocon Aerocon India. Rajkot
2. Aerocon HIL Golan
3. Ascolite Aswani Construcion Pvt. Ltd. Surat
4. Xtralite Ultratech. Hyderabad
5. Renacon Renaatus Procon Pvt. Ltd. Chennai
6. Reliconz Reliconz Brixs Pvt. Ltd. Hyderabad
7. JK smart Blox JK Lakshmi Cement. Jhajjar
8. Magicrete Magicrete Building. Surat
9. Prime AAC ECO-CARE Building Products Pvt.
Ltd.
Vijayvada
10. Siporex B G Shirke Group. Pune
11. Efcon Phenix Procon Pvt. Ltd. Bawla
12. Ecogreen Ecogreen Pvt. Ltd. Gandhinagar
13. Ecolite JVS Comastco. Sinnar
14. BBEL Avantha. Palwal.

22. CONCLUSION
 However it is difficult to replace the old materials with new one.
Comparative Analysis indicates that in almost all the parameters, the
AAC blocks have a superior edge over burnt clay bricks.
 The use of AAC blocks leads to savings in overall project cost; enables
to speed up the construction process reduced environmental and
social impact.
 Therefore we can conclude that use of ACC blocks over burnt clay
bricks is recommended. It is advisable to developers, contractors, and
individuals to encourage this product as its use is in national interest.

23. *REFERENCES*
1. www.aacindia.com
2. www.indiamart.com
3. www.constructionworld.in
4. www.grihaindia.org, Report by Atul Kapur, “HIL- Upgrading India‟s life spaces”,
26th February 2013.
5. www.iosrjournals.org , An Investigation of Using Aerocon Block and M-Sand in
Constructing Low Cost Housing K.Jaiganesh 1, S.Dinesh.
6. International Journal of Engineering Research & Technology (IJERT), Burnt Clay
Bricks Versus Autoclaved Aerated Concrete Blocks. A Comparative Analysis , By
Radhika Shukla, Architecture dept. MIET Nagpur University, Mumbai, India.