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Autoclaved Aerated Concrete production line - details see: https://www.machineto.com/autoclaved-aerated-concrete-production-line-aac-10076399

Autoclaved aerated concrete (AAC), also known as autoclaved cellular concrete (ACC) or autoclaved lightweight concrete (ALC).

Our company produces fully-automatic AAC production lines. We can provide our clients with wide range of different solutions from conventional raw materials like sand and lime to the very promising industrial waste recycling solutions like AAC made from fly ash generated from the elertic power plants and other facilities which use coal for burning.

Autoclaved aerated concrete was inventedby the Swedish architect and inventor Johan Axel Erikssonin the mid-1920s. AAC is a lightweight, precast building material that simultaneously provides structure, insulation, and fire and mold resistance. AAC products include blocks, wall panels, floor and roof panels, and lintels.

It has been refined into a highly thermally insulating concrete-based material used for both internal and external construction. Besides AAC's insulating capability, one of its advantages in construction is its quick and easy installation, for the material can be routed, sanded, and cut to size on site using standard carbon steelbandsaws, hand saws, and drills.

Even though regular cement mortar can be used, 98% of the buildings erected with AAC materials use thin bed mortar, which comes to deployment in a thickness of 1/8 inch. This varies according to national building codes and creates solid and compact building members. AAC material can be coated with a stucco compound or plaster against the elements. Siding materials such as brick or vinyl siding can also be used to cover the outside of AAC materials.

AAC has been produced for more than 70 years, and it offers advantages over other cementitious construction materials, one of the most important being its lower environmental impact.

• AAC’s improved thermal efficiency reduces the heating and cooling load in buildings.
• AAC’s workability allows accurate cutting, which minimizes the generation of solid waste during use.
• AAC’s resource efficiency gives it lower environmental impact in all phases of its life cycle, from processing of raw materials to the disposal of AAC waste.
• AAC’s light weight also saves cost & energy in transportation.
• AAC's light weight saves labour

Raw materials

Unlike most other concrete applications, AAC is produced using no aggregate larger than sand. Quartz sand, lime, and/or cement and water are used as a binding agent. Aluminum powder is used at a rate of 0.05%–0.08% by volume (depending on the pre-specified density). When AAC is mixed and cast in forms, several chemical reactions take place that give AAC its light weight (20% of the weight of concrete) and thermal properties. Aluminum powder reacts with calcium hydroxideand water to form hydrogen. The hydrogen gas foams and doubles the volume of the raw mix (creating gas bubbles up to 3mm (1/8 inch) in diameter). At the end of the foaming process, the hydrogen escapes into the atmosphere and is replaced by air.

When the forms are removed from the material, it is solid but still soft. It is then cut into either blocks or panels, and placed in an autoclave chamber for 12 hours. During this steam pressure hardening process, when the temperature reaches 190° Celsius (374° Fahrenheit) and the pressure reaches 8 to 12 bars, quartz sand reacts with calcium hydroxide to form calcium silica hydrate, which accounts for AAC's high strength and other unique properties. After the autoclaving process, the material is ready for immediate use on the construction site. Depending on its density, up to 80% of the volume of an AAC block is air. AAC's low density also accounts for its low structural compression strength. It can carry loads of up to 8 MPa (1,160 PSI), approximately 50% of the compressive strength of regular concrete.^[4]

Since 1980, there has been a worldwide increase in the use of AAC materials.

Raw materials compound in case if main raw material is Fly Ash:

Fly ash: 65-70% Lime: 8-25% Cement: 6-15 % Gypsum: 3-5% Aluminium: 0,08%

Production process description

1.Batching

2.Mixing

3.Mould pouring

4.Precuring

5.Tilting

6.De-moulding

7.Sides cutting

8.Horizontal cutting

9.Vertical cutting

10.Carts loading

11.Autoclaves loading

2.Hardening

13.Leaving autoclave

14.Hanging and stacking

15.Loading and packing

16.Side plate returning

17.Reorganizing with empty mould

18.Cleaning and mould spraying

19.Bar reinforcing for slab

Production Process Workflow

After selecting and weighing (1) of the raw materials, they are loaded into the mixer, mixed evenly (2) and filled (3) in the mould (if we producing sheets we are placing reinforcement into the mould (19)). After maturing (4) at a certain temperature, the raw block is a preliminary hardened, and transferred by crane for turning over and then to the cutting machine a) reverses the form of 90 degrees (5). remains as one sidewall to the bottom of the array on the rest of the process. b) inserts a form with an array on a cart or cutting machine, open and unload the form (6). c) links (17) blank form with reverse side walls (16). Collected forms are cleaned and lubricated with oil for the next pouring. On the cutting machine the block will be cut by an array of saws. A) vertical cutting surpluses on both sides (7) B) vertical cutting (8). In) horizontal cutting (9). After cutting the array together with the bottom using the crane is applied to the cart (10) to be loaded into an autoclave (11). The autoclave under high temperature and pressure, the process of hardening of concrete (12). After the array goes out of the unit (13), they add up (14) or packaged. After the removal of the array, the sidewall-bottom returns (16) for cleaning and connection with the form (17).

Fly ash block plant profit analysis

(according to China market, only as your reference)

1.One cubic meter AAC block using material cost :

No.	Item	Price(RMB/ton)	Consumption/m3(kg)	Unite Cost(RMB/m3)
1.	Fly ash	30	420	12.6
2.	Cement	360	72	25.92
3.	Lime	260	90	23.4
4.	gypsum	25	18	0.45
5.	Aluminium paste	14000	0.5	7
Total price:				69.37 RMB (about $10.67)

1. 2.One cube Acerated block other cost:

No.	Item	Price(RMB)	Consumption/m3	Unite cost(RMB/m3)
1	Burning Coal	800	30kg	24
2.	Demould Oil	3	1kg	3
3.	Water cost	2	300kg	0.6
4.	Electricity cost	0.8	6kw	4.8
5	Worker salary	12		12
Total price:				44.4RMB (about $6.83)

One cube meter block material cost:

69.37+44.4=113.77RMB (about $17.5)

Chinamarket:190 RMB/ m3 (about $29.23)

The profit rate:40.13%

one shift need 10-12 workers. One day(two or three shifts) need 20-24 workers