>>507873198
>structurally
Yeah, reinforced concrete is better here. You can blast out parts and that shit will still sand.
But if you want to go through it, rather than blow it up, it's a different story.
Drilling a hole into reinforced concrete is just as easy as through regular concrete if you don't hit a metal rod. And even if you hit one, you will eventually get through it.
The largest 'Murican bunker buster claims to be capable to get through 60m reinforced concrete.... which is a weird claim, because how the steel lattice is aligned inside the concrete will matter a lot, but it is what it is.

Meanwhile good luck trying to get through granite boulders.
Pic related is B8 Bergkristall where NatSocs assembled planes.