I have a lot of "pots" in my studio that didn't turn out as well as I thought they would. Either the shape wasn't right, or the colour a bit different from my expectations. Sometimes when I fire things, the slightest difference in temperature can change the shade. So, my plan is to do a retaining wall with cement/concrete(what's the difference) and put broken coloured pottery in it, like a mosaic.
Concrete has larger aggregate in it (gravel usually).