Collect a few of the really heavy duty used election signs and you could easily try it out. There are some pages on the web regarding which glues and glue systems, along with other joinery methods work on coroplast. Its a pretty durable stuff, and 4-8mil coro would probably outperform any similiar thickness cardboard, and be way more waterproof while doing so. Also, you can, if you care to go this far, build in ribs and ridges to add strength and rigidity.