Production of Autoclaved Aerated Concrete Blocks from 600 to 750 kg/M3 Density
Main ingredents (Raw Materials) and approximate quantity per Cubic Meter
- Water - 200 - 280 Ltrs
- Ordinary portland cement (OPC 53 Grade) – 90-110KG
- Quick lime - 40-60KG
- Gypsum - 5-10KG
- fillers (fly ash/fine sand) – 450 – 550KG
- Aluminum powder – 400-500Gms
- Additives – quantity depend on raw material properties
Water for concrete mixture shall of any suitable drinking water. It is preferable to water from surface sources, unsalted, soft or medium hardness.
- Portland Cement
Virtually all of ordinary portland cement (OPC 53 Grade) suitable for the production of aerated lightweight concrete. Cement should be fresh, lumps free. Preferred use of good standard brands.
- Quick Lime
Quick lime powder required for the AAC production. It is a main binder. Higher purity gives better result.
Gypsum is commonly used as a mineral additive in production of autoclaved aerated concrete (AAC)
As part of concrete mix fly ash / fine silica sand can be used as filler.
Fly ash / pond ash is available from thermal power plants (fly ash is silica rich product, which is industrial waste obtained from thermal power plant). Also fine silica sand can be used as filler.
- Foaming Agent
Small quantity of pure aluminum powder is used for foaming of concrete.
Just like other concretes, additives such as activators / accelerators may used to improve and stabilize the quality of final product.
Process of production -
- Measured quantity of water is poured in primary slurry mixer.
- Measured quantity of fly ash is added in primary slurry mixer. Mixed well and checked the density of slurry. To obtain the desired density,need to add more water or fly ash.
- Pour desired quantity of prepared slurry in to main mixer.
- Desired quantity of cement is then mixed with fly ash slurry.
- Desired quantity of lime and gypsum are added to the mix.
- Additives are poured in mixer.
- Mixture is heated with the help of steam up to the required temperature.
- Aluminum powder premixed with small quantity of water is added in mixer. mixed up to 45 seconds.
- Prepared mixture is poured into the molds.
- After filling, mold moved towards pre-curing area
- In filled mold, concrete slurry rises and volume increases up to desired height in 15-20 Minutes.
- In 2-4 Hrs. raised concrete gets its initial strength and mold panels are removed for cutting process.
- Then this concrete “cake” is sliced in required sizes Horizontally and then Vertically with the help of cutting machines.
- After cutting the mold base trolley is pushed inside the Autoclave.
- In autoclave steaming process is done with pressurized steam. Typically 12KG pressure. Depending on raw material properties, This curing cycle takes approximately 12 hours.
- After completing steaming (autoclaving) process, hardened blocks are removed from mold base trolley and shifted to the storage area. These are ready blocks and can be shipped immediately.
Note : Raw material quantity is depend on quality of raw material. it may vary from place to place