Aerated Concrete -Manufacturing -Advantages-Disadvantages
What is meant by Aerated concrete?
It is a composite of cement, lime, fly ash, and gas former (aluminum powder). It is a high efficiency thermal insulating material made through the processes of molding and steam curing.
There are different ways in which Aerated concrete can be manufactured.
- By the formation of gas by a chemical reaction within the mass during the liquid or plastic state.
- Mixing preformed stable foam with the suspension.
- By using finely powdered metal (usually aluminum powder) with the suspension and reacted with the calcium hydroxide released during the hydration process, to give a large amount of hydrogen gas. This hydrogen gas when contained in the suspension mixture, gives the cellular structure.
- Zinc powder can also be added instead of aluminum powder. Hydrogen peroxide and bleaching powder have also been used in place of metallic powder. But this practice is not widely followed today.
- In the preformed method, the stable foam is mixed with cement and grout of crushed sand, thus causing the Aerated concrete structure when this hardens and hardens. As a minor modification, some foaming agents are also mixed and thoroughly agitated to obtain a foaming effect on the concrete.
- Similarly, a large number of airborne agents can also be used and mixed thoroughly to introduce an Aerated concrete structure into the concrete.
- However, this method cannot be used to decrease the density of concrete beyond a certain point and, as such, the use of air entrainment is often not practiced to make aerated concrete.
- The gasification method is one of the most widely used methods that use aluminum powder or other similar material.
- Aerated concrete the practices of using foam performed with mud is limited to small-scale production and on-site work where small changes in dimensional stability can be tolerated. But the advantage is that any desired density on the site can be done in this method.
Advantages of Aerated Concrete
- The improved thermal efficiency reduces the heating and cooling load in buildings.
- The porous structure provides superior fire resistance.
- Workability allows precise cutting, which minimizes the generation of solid waste during use.
- The efficiency of resources gives it a lower environmental impact in all phases of its life cycle, from raw material processing to waste disposal.
- The lightweight saves costs and energy in transport, labor costs and increases the chances of survival during seismic activity.
- The larger blocks lead to faster masonry work.
- Reduce the cost of the project.
- Environmentally friendly.
- Great ventilation.
Disadvantages of Aerated Concrete
- Installation during rainy weather.
- Accessories: the fragile nature of the blocks requires longer and thinner screws when installing cabinets and tapestries and drill bits or hammers suitable for wood.
- Special large-diameter wall plugs are available at a higher cost than common wall plugs.
- Insulation requirements in the new building codes of northern European countries would require very thick walls when using AAC alone.
- Therefore, many builders choose to use traditional construction methods by installing an additional layer of insulation around the entire building.
AAC block Manufacturing process
- Step 1 - Raw material preparation
- Step 2 - Sand grinding
- Step 3 - Automated mould closing
- Step 4 -Mould transport
- Step 5 - Casting process
- Step 6 - Pre curing
- Step 7 - Green cake form
- Step 8 - Cutting line
- Step 9 - Cross cutting
- Step 10 - Vertical and horizontal cutting
- Step 11 -Veccum crane (crust recycling)
- Step 12 - Green cake stracking
- Step 13 - Finally loading process and stored