Quote Originally Posted by cognitdiss View Post
The "stone" you speak of is the the gravel aggregate that is mixed with cement to make concrete. All concrete has aggregate.
Indeed the concrete itself is "locally quarried" limestone.
Both usually come from within a few hundred miles of the mixing plant, which should be within 50 miles of the site.
That said there is little to any coarse aggregate in shotcrete, from what I saw. It is more akin to grout, with very fine aggregate such as sand. It's probably a pretty hot mix at that, I don't know how they keep it watered.

Quarrying actual stone that is recognizable as such is a much more difficult and expensive undertaking.
Cutting said stone is even more expensive and difficult.

No, I don't mean aggregate. Concrete is the matrix, not the filler (aggregate, fiber, etc.). Not all concrete has aggregate.

Neil