@thraeryn this would probably work pretty well:
I used it to glue concrete landscaping blocks together and it's pretty permanent. If you can break apart the blocks at all you basically end up with a chunk of one block still stuck to the other, and the bonds have lasted years so far.
Not sure how different a concrete-to-asphalt bond would be. I think similar, but asphalt isn't as solid so blocks might get yanked off with a chunk of road? Worth trying though.