It's easy to test this. Please do so, and then discuss your findings, rather than just repeating assertions that appear to be nothing but trolling. I have seen enormous amounts of steel that has been coated with zinc, a process called galvanization, and so has everybody here.

Never have I noted that steel becoming useless structurally.

This allegation is baseless, almost certainly false, and appears to be intended to poison the well of rational discussion of the terrorism executed by the US government against American civilians to keep them cowed and obedient to profitable quasi-slavery.

You can easily buy pure zinc at any marina, because it is sold to decrease corrosion of other metals, and use it to test whether or not galvanization turns steel into trash. However, just considering the claim logically reveals it's almost certainly nothing but disinformation - a lie - intended to prevent people from considering actual facts.

Repeating it without rational consideration, or better yet, actually testing it, is harmful to folks facing the horrifying prospect of being ruled by despots via terrorism.

Please don't do that.