Aircrete comparison.

  • Major Contributor

    HI. I am new to the forum. I was reading about your aircrete and the aircrete the is manufacured as described in Wikipedia and the patented and historical process used around the world. What they call aircrete have a different composition with lime, aluminum and other minerals and it is baked on an autoclave as blocks with a precise temperature and pressure. That is the manufactured aircrete blocks they sell. How your aircrete compares to that one? Because just cement powder and foaming agents are not going to have the same strengh and finish as the manufactured one I can guess. Also, can you use your aircrete to cover a rebar dome and would it hold with structural strengh? I would like to use your aircrete and molding process and add rebar to the aircrete wall. I was thinking to use your aircrete to hold the rebar instead of urethane , as they do in the monolithic dome process , and then use normal shotcrete over aircrete to reinforce the final product. Do you think this could be done? Thanks for the great website and information.

  • Hi Joe, the Wikipedia information you describe sounds like Autoclaved aerated concrete (AAC). I coined the term AirCrete, when I invented the Green Dragon, but it's nothing new. It's the same material called Cellular Concrete, or Foamed concrete, etc. It's been around a long time and it's a big industry around the world. Concrete companies often charge more for
    cellular concrete then conventional concrete because it's a specialty product. Conventional equipment is costly, heavy and requires a lot of power to operate. I've simple made it Cellular concrete accessible for the DIY builder. It's very inexpensive and easy to produce yourself with our equipment. All you need is a small $100 air-compressor.
    AirCrete is very strong when reinforced properly. It has good compression strength but poor tensile strength.
    I dont' have any experience reinforcing with rebar as you describe. Nor is it something I'm interested in. There are easier and better ways to reinforce AirCrete.
    My preferred method of reinforcement is to apply reinforcing fabric to the surface of the structure. Polyester reinforcing fabric is inexpensive, very strong and it doesn't rust, rot or decay. It's an appropriate and wise use of a natural resource.
    You can also add fiber into the mix for tensile strength. PVA fibers work great. We haven't been able to get hemp fibers yet, but they probably will work well too.
    Good luck, I'm interested in what you discover.

  • Major Contributor

    Thanks for clearing that up. Somehow wikipedia uses the term aircrete for the process I described, so know I know that there are 2 diferent methods. I would love to try your low cost method with basalt rebar, which is a rebar make of molten volcanic mineral material and composite, and 80% lighter than metal rebar and stronger that comparable diameter steel rebar. It can be bought from Chinese suppliers for about 300 dollars for metric ton. For me, your material lends itself to be used in place of the urethane they presently use to hold the metal rebar together in airform monolitic dome construction. With basalt rebar and your material, a low cost dome could be built that can be then shotcreted either outside or inside, making it even stronger and eliminating the expensive airform that the monolitic dome suppliers sell as part of their kits. Just an idea of how it could be made better in tensile strengh with basalt rebar, which also dont even get corrosion because it is basically a rock composite. Thanks again and I will keep in touch. Also I am interested in your next workshop in August.

  • Thanks Joe, good luck with your project. The basalt products are impressive. When I tried to order some they were very expensive to bring to Hawaii so I haven't experimented with them yet. Let me know what you discover. Maybe we can get some for the Aug workshop?

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