I'll give you the same answer I got at my LHS when I asked about buying rail without ties - get sections of flex track and pull the rails out. I've never used concrete tie track, but I'd imagine the rail would pull out about the same.
It takes an iron man to play with a toy iron horse.
For decorative use?
Shapeways?
https://tinyurl.com/yddy5aur
Good luck, Ed
I'm looking to buy HO Scale concrete ties without the rail. Does anyone sell them?