<HTML>Sandy/Litz:
Good points. You have seen the recipe for geopolymer in previous posts (salt, lime, shells, etc). The shells in the mix would tend to act like iron wire/rods in concrete. However, they would hardly constitute enough strength to hold together a composite of the nature that Sandy is describing.
In actuality, having handled the coral stone from the Coral Castle.... well, let me tell you what happened...
After my last visit to Homestead, I brought back a piece to my office to show my assistant. She picked it up, and her first comment was how light it was (in actuality, it is extremely porous, with some bubbles of almost an inch in diameter all through it). She then commented on how strong it was... nothing like the brittle stone I had described to her... and then she started apologizing profusely as she "accidentally" broke the stone into three pieces with her bare hands.
This is probably a great example of a geopolymer that was formed without pressure, and without a structural assistant like shells or wire.
How important is the pressure to the formation of limestone, and what part of Davidovits' recipe would take the place of the pressure?
Anthony</HTML>
