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Heading: 1.1Production of autoclaved aerated concrete
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I'm interested in the production of autoclaved and non autoclaved aerated concrete. I've been searching some information about it and I still have too many questions that I haven't found their answers anywhere. I would appreciate if you answer my questions and give me some sources about AAC and non AAC.

Thank you!

1. Is any additive used during the production of aerated concrete to make a homogenous dispersion? I looked for many information about it but I couldn't find anything, except usage of Al powder for making air bubbles. But I can't find out how they make a homogenous dispersion of air bubbles. I think that air entering additives may be used but I'm not sure about it.

2. I saw in some articles that, producers use more sand than cement during the production of aerated concrete. If we use more cement than sand, could the product become more lighter and stronger? Will there occur any side effect to the product by using more cement than normal amount.

3. I noticed that generally 90 microns of sand are used. What should be the interval on the sand?

4. As far as I understood the quantity of the water is more than that of the normal concrete. Knowing that the use of extra water reduces the resistance of the concrete, do they use a plasticizer to prevent it?

5. Can set accelerating additive be used on aerated concrete?

6. The additives which are used at normal concrete, can they also be used for aerated concrete or are there special additives for this?

7. Is there any alternative for Al powder and what should be its main speciality that will required?

8. Do the answers to these 7 questions apply to non autoclaved aerated concrete as well?



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Nursel Eren


Nursel,
You've asked more questions than a quick answer on this forum could do justice to.

I suggest you have a look at the chapter on Cellular Concrete by Fouad in ASTM STP169D.

For non-autoclaved foamed concrete look for articles by Jones (University of Dundee) or Kearsley (University of Pretoria)

Also ACI 523.1R and 523.3R.

Also google "Neopor System GmbH".

For autoclaved foam concrete try ACI SP 226.

After you have a look at some of the above, feel free to come back with some more specific questions.
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Alan Kirby
 
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