That sounds cool as hell.
I've seen wood with epoxy poured to encapsulate paper things on wood. That holds up under abuse for years.
The cool thing about pouring epoxy is that it is self leveling. A trick I used was to run a hair dryer over it to release any air bubbles.
There is a 'work time' and then a cure time. This might vary depending on the product. Depending on the size of your floor you might have to consider sections?
My concerns would be the cost to epoxy a floor thick enough to bury the covers and then some. Also what glue would affix the paper to concrete.
It might be worth it to grab a bag of concrete and mix a test slab and experiment before you commit time and money to a floor. You can turn those into garden stepping stones.
I does sound cool.