Casting a stone wall.

[tetters]

I like the idea of gauze or some metal window screening in there to act like a re-bar of sorts. You also mentioned air bubbles and I wonder if they could also be trapped in the pour and causing some weak spots. I wonder if you could try to lightly vibrate the mold to get all if not most of the air bubbles out if that might help make the wall more structurally sound.