AUTOCLAVED AERATED CONCRETE-A SUSTAINABLE BUILDING

MATERIAL

Submitted by

Anuya BhideAkshata DeshpandePramod MandadeSamira Ahmed

Need for AAC

Problem of disposal of fly-ashTop soil erosionSand crisisPollution caused in manufacture of clay

bricksIncrease in demand for cement, sand, steelTotal environmental imbalance

Solution……Autoclaved Aerated Concrete

What is AAC?

AAC is a lightweight product consisting of calcareous materials and/or lime and siliceous fine materials and water to form a homogeneous cell structure.

Cellular structure is attained by the inclusion of microscopic voids originating from a chemical reaction.

It is recommended by Indian Green Building Council (IGBC) as for material of choice for LEED certification and offers cost savings up to 40% due to huge savings in structural costs and increase in floor space area.

CLOSE–UP VIEW OF AAC

Properties of AAC

Light weight Workability

Acoustic Insulation

Mold and Pest Resistance

Fire Resistance

Properties of AAC

Thermal insulation provided by AAC

Graph for k values of different construction materials

Properties of AAC

Other important properties:DurabilityImproved Indoor Air QualitySustainable under seismic loadsCost Effectiveness.

Comparison of properties of the different building materials

Sr.

No.

Properties AAC Clay Bricks Concrete Blocks

1 Basic Materials Cement, Sand,

Fly-Ash and

Aeration

compounds

Top

agricultural

Soil

Cement, Sand

and Aggregates

2 Dry Density (Kg/m3) 800 1900 1700

3 Co-Efficient Of

Thermal Conductivity

(k)

0.16 0.84 2

4 Sound Insulation Superior Normal Better

5 Workability Good (Can be

cut, sawn,

nailed, drilled)

Normal Difficult

6 Energy Efficiency Can Consume

fly-ash, Low

energy

requirement

Top Soil

Erosion,

High Energy

Requirement

Medium

Energy

Consumption

7 Eco-friendliness A green

product

Creates

pollution

High sand

consumption

Manufacture of AAC

The manufacturing process of AAC is completed in to the following four steps:

1) Assembling and mixing of the raw materials.

2) Adding of the expansion agent.

3) Expansion, shaping, pre-curing, and cutting.

4)Final curing utilizing an autoclave.

Sand ground to require finenessSand is ground to

the required fineness

raw materials batched by weight and

delivered to the mixer.

water and expansive agent are added to the

mixer

the slurry is poured into the

molds

the initial hydration of cementitious

compounds gives sufficient strength to

hold its shape in a few hours

the volume increases by 50% in the molds within 3 hours, due to expansive agents.

aerated concrete product is

transported to a large autoclave, where the curing

process is completed.

AAC units are normally placed on pallets for

shipping

Overall Steps in Manufacture of AAC

AAC blocks ready to be removed from Autoclave

Exterior view of Autoclaves

Interior view of Autoclaves

Environmental Benefits of AAC

produces no waste products or pollution.avoid usage of topsoilmanufactured with abundant recycled raw materials such

as fly-ash reduces energy consumption.

Methodology

Study of AAC- includes1.Need for a substitute2.AAC as a solution3.Properties of AAC4.Manufacturing of AAC5.Environmental benefits by use of AAC

Methodology

Comparison of AAC with clay bricks- includes1.Sustainability2.Cost effectiveness3.Environmental benefits

Expected results

AAC is a better product which can solve some of the alarming problems in the construction industry.

Hence its use in construction should be increased in order to have building with less impact on the environment.