Originally Posted by Scout
We are in So. Ga. I doubt there is any salt in our sand. I'm going to try it. I'll let you know how it goes.
Did anyone have any experience with clay in cement? Plaster in cement?
I use the fine white Unimin quartz sand in the bag, it's perfectly clean, dry, free of any foreign material, it comes in 50# plastic bags. I prefer this over trucked in sand which is always wet or damp, and if dumped outside- cats, leaves and debris become an issue, if it stays there long enough you get grass or weed seeds sprouting quickly and their roots create a headache to sift out.
I'm trying to move away from concrete in favor of terracotta.
Clay I doubt will help anything, and likely make weak concrete, if you put plaster in concrete you essentially get USG's Hydrocal or Hydrostone gypsum cement. USG's spec sheets show that they add Portland cement to the gypsum but not the exact amount.
I can say from tests that neither Hydrocal or Hydrostone last outdoors, you get this after about 3-4 years, they weather and disolve away like sandstone rocks in the Utah desert have: