I'm laying a 20 foot square slightly sloping concrete slab onto which a pig sty will be built. (18" block wall topped by several rows of scaffold poles between piers)
At the lower edge I want to in-situ cast a 6" semi circular drainage channel inside the sty to lead run off into a settling tank. If it wasn't a sty I'd set some aco drain before the concrete pour, but this would block too quickly and not be easy to clear.
But how the heck, given 6 cu M of concrete riddled smooth and rapidly setting do you form a channel???? Indeed is it possible?
AWEM