Hi Jim, Hola: The first thing you would need to understand is that aircrete is a commercial name for another process that involves aluminum powders and autoclave oven to do the finished product, which have higher compression and tensile strenghs than what you would do with just soap. A better name for the type of block that domegaia builds would be cellular concrete. It also depends how your local office works. If they only want enginnering data to approve and they are not going to actually test or see the process, then you can get that information online from different companies brochures. Now if you want the real data, you need to fabricate a cellular concrete block and send to a local engineering firm to be tested , normally it will require 4 or 5 blocks and the test can take up to 60 days. Then you can use those numbers for the county. Domegaia do not sell a block with engineering data. They sell a method and the tools to get it done.
Since you are using an octagonal form, a good way could be to fabricate triangles with cellular concrete using the domegaia method and put a lath mesh in the middle on the triangle before pouring and extend this mesh outside of the triangle area. Then you can put these triangles together and build a geodesic dome. You could build a wood geodesic dome frame and use it as support, then when the triangles are in place, put rebar rings to hold the triangles together using the lath mesh, and then fill up the sems with either cellular concrete or just a stronger regular concrete mixture. You can them remove the wood frame from the inside and have spray or install inner insulation and stucco to your needs. This is how geodesic homes of Florida do them, but they do not use aircrete and their triangles have the insulation glued to the concrete triangle. Look at this page so you get an idea:
Another idea for you is that instead of using regular portland cement, you use magnesium cement, which is much stronger and then you can make thinner walls but with the same strengh. Magnesium cement is much more expensive than portland, but then again it gives so much strengh that you maybe could combine it with portland and get a happy medium. I hope this helps. Happy building.