Autoclaved aerated concrete is used for manufacturing of precast
elements namely roof elements and wall elements .In AAC,fly ash is used
to the tune of 80% of total mass of total mass the elements.The density
of AAC products is in the range of 600-1000 kg/m3..
AAC is produced by a highly developed factory process under the careful
control of chemists and Engineers.The basic raw material are mixed with
water form a slurry to which aluminum powder is added,carefully to arrive
at desired density of final product.Chemically coated,high strength welded
steel reinforcement in the form of cages is hung in the moulds with special
holding arrangement. The concrete get bulged due to the hydrogen bubbles
that evolve from the reaction between aluminum powder and the alkaline
slurry.As the slurry sets the hydrogen within the cellular structure diffuses
and is replaced by air.
AAC products are then placed in autoclaves for steam curing at high temperature
and pressure.The final product i.e calcium silicate hydrates are formed
in the autoclave.
Advantages of AAC:
Light weight construction hence lighter foundation
Faster construction
Higher thermal and sound insulation
Higher resistively to fire
Lesser size of structural member i.e. lesser section of beams and columns.
