Decided to come with something interesting:
After WW2 an Norwegian company bought the steal of the German battleship "Tirpitz". and for over 10 year worked on "Tirpitz" to get all it's steal. many of the steal plates frome this ship, specialy the inner armor plating, an the back wall armor plating on the torpedo bulge was bought up by several Norwegian road company's. main reason for this was that the steal was very strong but did also flex a little, something that mad it possible for them to protect large opening in the ground, while big heavy trucks could drive on it. 70 years later they are still in use in all over in Norway.
The plate in the picture bellow is one of the smaller one, and it weights 5 tons:
I have personally seen "Tirpitz"-steal plates, large plates that had covered large hulls, where they had mounted f*** big crane on top and under the steal plate... workers was working!