With WinRAR you can specify the use of a recovery volume which will allow an entire CD/DVD from a recovery set to be destroyed and still be able to recover from the remaining disks. For example, I use WinRAR to backup a set of files/directories by compressing them into a RAR archive, using the span options to set it to span to the size of a DVD(or whatever media you are spanning, the size of a tape backup, etc.) and also set a Recover Volume of 1 or more (found under Advanced tab in the Volumes section, and requires that you have set the Split To Volumes on the General tab, this is different from a Recovery Record so don't confuse them).
With a Recovery Volume an extra Rar file will be created in the set. Some sort of parity is used such that any one of the rar files in a set can be lost and the remaining files can still be used to recover all of the data. You could use Recovery Record as well to allow for a certain amount of damage in all of the rar files.
You can then test the integrity of the data periodically by performing a test extraction. I don't know if you'll get any feedback about the damage of the files. You could easily test this by purposely damaging a file in a set. With a Recovery Volume the data should still be extracted, but hopefully WinRAR will display some feedback in it's console about the damaged archive.