Reported via Discord, can't do this with regular concrete but can with chiseled. Investigate whether this was intended to be disabled and ensure the variations are also disabled if so.

Image from discord:

This recipe should probably be removed, both from the crafting grid and the macerator, as it skips having to make the liquid concrete in the mixer. The removal should be fairly easy, as both are oredict inputs. However, then that leaves a separate recipe to obtain the chisel concrete, via concrete powder and vanilla's in world crafting, so maybe the recipe for vanilla concrete powder should be adjusted to be inline with the desired gtce recipe, as I am assuming we cannot change the in-world crafting to make it in a mixer.