alt Hacker News> It's why rebar rusting out destroys concrete structures
That isn't really why. The loss of tensile strength from rebar decomposition isn't what kills it.
Steel expands as it rusts. It breaks apart the concrete via expansion just like freezing water would. If you had a mix of steel and stainless steel rebar, the rusting of the normal steel would destroy the concrete all the same.
Good point. The steel rusts, expands, more water gets in, more rust, concrete cracking, exposed rebar, rebar rusts away, no tensile strength, collapse.
(I was going to link to a picture, but at least half the images of corroded rebar found by search are AI-generated. Bogus technical pictures are getting out of control. Just saw some of the construction of the Panama Canal. No, steam shovels there did not have cowcatchers.)