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ABOUT AAC

AND ITS USE

(AUTOCLAVED

AERATED CONCRETE)

• AAC is one of the major achievements

of the 20th century in the field of wall construction.

It is a revolutionary material offering

an unique combination of high durability

and strength, low weight, unprecedented

buildability and superior ecological green

features.

• AAC is a high-quality, load-bearing and

extremely well insulating building material

produced as standard or mega blocks or

panels.

• AAC is a long proven material. It has successfully

been used in Europe since early

last century and is now among the mostly

used wall building materials in Europe with

rapidly growing market shares in Asia, the

Middle East and recently America.

• AAC is the material of choice for all

building applications, including homes,

multi-family, seniors housing, hotels, commercials,

schools, hospitals, sports halls,

etc. – an excellent building material for all

climatic conditions. It is used for all walls,

external or internal, loadbearing or nonloadbearing

walls, basement walls, infill

walls to framed structures, party walls, fire

break walls, etc.

• AAC is a steam-cured mix of sand or pulverized

fuel ash (PFA), cement, lime, anhydrite

(gypsum) and an aeration agent. The

high-pressure steam-curing in autoclaves

achieves a physically and chemically stable

product with an average density being

approx. one fifth of normal concrete. AAC

comprises myriads of tiny non-connecting

air bubbles which give AAC its diverse

qualities and make it such an excellent

insulating material.

A | AAC Blocks and Panels

Excellent heat insulation

6 times superior to clay bricks.

Fire resistant

more than 4 hours in 9 cm thickness.

Noise absorption

is superior than traditional clay bricks.

Easy workability

and 3 times faster than traditional masonry.

7


8

A | AAC Blocks and Panels

QUALITIES OF AAC

BLOCKS AND PANELS

Compare always cost and features of a

ready-installed wall of AAC with a wood

stick wall or a wall of bricks or concrete

blocks. The finished AAC wall features all

benefits, such as:

Ecological green building

Qualities:

• energy efficient

• best thermal insulation, 6 to 10 times

better than regular concrete = heat and

aircon saver

• environmentally friendly, non-toxic

• unsurpassed fire-resistance =

– life saver

– property saver

– insurance cost saver

• excellent sound absorption, ideal for the

hotel industry

• production process develops non-toxic

gases

• no waste of raw materials (water, fresh

cut-offs, etc. are all fully recycled into

production)

• industrial byproducts like PFA (pulverized

fuel ash = fly ash) of coal fired

Unsurpassed Fire-rating (average)*:

Block thickness, (mm)

minimum (inch)

Fire-rating (hours)

Non-load bearing wall DIN*

ASTM**

50

(2)

75

(3)

power plants can be used and are turned

into useful building materials

• recycling of breakage, rejects, etc.

• lowest energy consumption per cbm

(cft) during production in comparison to

other wall building materials

• saves resources: 1 m 3 (1 cft) of AAC

requires 0,2 – 0,25 m 3 of raw materials

only (0,2 – 0,25 cft)

Economic Qualities:

• competitive price = high economy

• high durability = long life, impervious to

rot or pest

• hurricane and earthquake resistant

• increased comfort and functionality of

the building

Physical Qualities:

• good workability, better than wood (can

be sawn, drilled, nailed, milled on site)

• large in size, however light weight =

considerable savings of structural costs

(loadbearing walls, foundation, piling

etc.)

• low weight results in easy handling and

rapid laying by the mason

• high load-bearing strength

• dimensional accuracy

115

(4 1 /2)

150

(6)

0,5 1 – 1,5 2 3

4

4 4 4

Load bearing wall DIN* 0,5 – 2 1 – 3 1,5 – 2 2 – 3 3

175

(7)

200

(8)

240

(10)


… MORE ABOUT AAC?

ENERGY EFFICIENCY

Great Energy Efficiency

High energy efficiency is one of the determining

characteristics of autoclaved aerated

concrete. AAC‘s cellular structure gives

it a thermal efficiency 10 times higher than

that of aggregate concrete and six times

better than clay brick. Consequently, buildings

made of AAC are warm in winter and

cool in summer.

With buildings consuming 40% of global

energy, greater use of AAC, both in construction

and renovation, offers an immediate

solution to cutting the energy consumption

of residential and non-residential

buildings across the globe.

AAC‘s excellent inherent thermal insulation

properties not only reduce the need

for heating and cooling, thereby cutting

carbon dioxide emissions and combating

climate change, but also make the use of

additional insulation materials unnecessary.

EU insulation requirements can be

met by using AAC alone. By contrast, aggregate

concrete, clay brick and calcium

silicate masonry units need to be used

in combination with insulation products,

thereby adding to their cost and environmental

impact.

AAC is energy-efficient over its whole life

cycle. Its production requires less energy

than other construction materials and its

light weight saves energy in transportation.

Because of the considerable thermal mass

AAC has the ability to store and release

energy over time. An increased comfort in

climates where outdoor temperatures fluctuate

strongly over a 24 h period.

FIRE RESISTANCE

Excellent Fire resistance

Autoclaved aerated concrete provides the

highest security against fire and meets the

most stringent fire safety requirements.

Due to its purely mineral composition, AAC

is classified as a non-combustible building

material. It is both resistant to fire up to 1200° C

and, unlike other construction materials,

heat-resistant.

Therefore AAC can be used as a fire wall

to prevent fire from spreading, thereby

protecting lives and economic assets. In

principle a fire wall should last up to four

hours, but tests have shown that an 150

mm thick AAC fire wall can resist at least

for six hours. In a real blaze, an AAC fire

wall even survived intact for 120 hours.

Some insurance companies offer reductions

in fire premiums for buildings

equipped with AAC fire walls.

In addition to internal fire walls, constructing

outer walls of AAC contributes significantly

to fire safety as most blazes start

outside buildings.

Besides being fire- and heat-resistant, AAC

does not give off any smoke or toxic gases,

which can endanger human life more than

fire itself.

STRUCTURAL

PERFORMANCE

Outstanding structural

Performance

Autoclaved aerated concrete is extremely

strong and durable despite its light weight.

AAC‘s solidity comes from the calcium silicate

that encloses its millions of air pores

and from the curing process in a pressurised

steam chamber (autoclave). Its excellent

mechanical properties make it the

construction material of choice for earthquake

zones.

AAC‘s light weight ensures that the foundations

of a building are lightly loaded, yet

it is strong enough to bear several floors.

It retains its properties for the entire life

of a building. AAC resists wind, rain and

storm and does not decay or rot. In general,

changing outside temperatures cannot

damage AAC.

A | AAC Blocks and Panels

9


10 A | AAC Blocks and Panels

RESOURCES

Autoclaved Aerated Concrete (AAC) is an

environmentally responsible building material

that conserves material and energy

usage in manufacture as well as energy efficiency

of the building.

High resource Efficiency, low

environmental Impact

Autoclaved aerated concrete‘s high resource

efficiency gives a low environmental

impact in all phases of its life cycle, from

processing of raw materials to the disposal

of AAC waste.

Raw Materials

AAC is made from naturally existing materials

that are found everywhere

– lime, fine sand, other siliceous materials,

water and a small amount of aluminium

powder (manufactured from

a by-product of aluminium) – plus

cement.

Production

Thanks to continuous efficiency improvements,

production of AAC demands relatively

small amounts of raw materials per

m 3 of AAC (1 m³ of raw materials results in

Consumption of raw materials and energy needed for production of

building materials *

1600

1400

1200

1000

800

600

400

200

0

Clay bricks

p = 1,2 kg/m 3

Consumption of raw materials in kg/m 3

Consumption of energy in kWh/m 3

5 m 3 of finished AAC), 5 times more than

any other construction products. No raw

materials are wasted in the production

process and all production offcuts are fed

back into the production circuit.

The manufacture of AAC requires less energy

than for all other masonry products,

thereby reducing use of fossil fuels and associated

emissions of carbon dioxide (CO 2 ).

Energy is also saved in the curing process

since AAC is steam cured at relatively low

temperatures and the hot steam generated

in the autoclaves is reused for subsequent

batches. Industrial-quality water is used

and neither water nor steam are released

into the environment. Non-toxic gases are

created in the production process.

Transportation

AAC‘s light weight also saves energy in

transportation. As AAC is up to five times

lighter than concrete and two to three times

lighter than clay brick CO 2 emissions are

significantly reduced during transport.

Reuse, Recovery and

Disposal

Throughout the life cycle of AAC, potential

waste is reused or recycled wherever possible

to minimise final disposal in landfill.

Porous clay

masonry units

p = 0,8 kg/m 3

Calcium silicate

masonry units

p = 1,4 kg/m 3

AAC

masonry units

p = 0,4 kg/m 3

*Source: FeBeCel handbook 2000: Le Béton Cellulaire – Matériau d’ Avenir, p. 32


Blocks

• length up to 625 mm (2 ft)

• height 200 – 400 mm (8‘‘ to 16‘‘)

• thickness 50 – 400 mm (2‘‘ to 16‘‘)

Megablocks

• length 625 to 1250 mm (2 ft to 4 ft)

• height 625 mm (2 ft)

• thickness 100 – 400 mm (4‘‘ to 16‘‘)

Panels

• length

– floor high 2.50 – 4.30 m (8 ft to 14 ft)

as vertical wall panels

– long up to 6.00 m (20 ft)

as horizontal or vertical wall and roof/floor panels

• width 625 mm (2 ft)

• thickness 75 – 300 mm (3“ to 12“)

Strength class

according

to DIN

*Density *Average Compressive

Strength

Thermal

Conductivity

t/m³ lb/cft N/mm² psi W/mk (BTU·in/ft²h°F)

PP2-035 0.35 22 2.5 350 < 0.11 < 0.76

PP2-040 0.40 25 2.5 350 0.11 0.76

PP2-050 0.50 30 2.5 350 0.14 0.97

PP4-055 0.55 33 5.0 700 0.14 0.97

PP4-060 0.60 35 5.0 700 0.16 1.11

PP6-070 0.70 40 7.5 1000 0.18 1.24

*Ref. DIN 4165

Note: The compressive strength and density to be achieved depend on the raw material quality and on the mix

formula.

Strength

Class

Nominal Dry

Bulk Density

Density

Limits

Compr.

Strength

psi (MPa)

Average

Drying

Shrinkage

Thermal

Resistance

(8 in. wall

thickness)**

R-value

lb/ ft³/ kg/ m³ lb/ ft³/ kg/ m³ min (%) (hft² °F/BTU)

AAC-2 25 (400) 22–28 (350)–(450) 290 (2.0)

31 (500) 28–34 (450)–(550) 11.5 – 9.2

AAC-4 31 (500) 28–34 (450)–(550) 580 (4.0) ≤ 0.02

37 (600) 34–41 (550)–(650) 9.2 – 7.4

44 (700) 41–47 (650)–(750)

50 (800) 47–53 (750)–(850)

AAC-6 37 (800) 35–41 (550)–(850) 870 (6.0)

44 (700) 41–47 (650)–(750) < 7.4

50 (800) 47–53 (750)–(850)

Ref. ASTM: C1386-07

**including air film coefficients

A | AAC Blocks and Panels

TYPICAL

SIZES

(other sizes

possible)

EUROPE

11

Physical

Characteristics

(DIN EN)

USA

Physical

Characteristics

(ASTM:

C1386 - 07)

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