>I did a quick check, and it looks like rebar concrete has a lifespan of about 50 years, The variability based on type of rebar and the environment it is insta

>I did a quick check, and it looks like rebar concrete has a lifespan of about 50 years, The variability based on type of rebar and the environment it is installed in is too high to make statements like that. Galvanized rebar in concrete in non-marine environment will last hundreds of years. The concrete will probably crumble around it before the rebar corrodes if there's any appreciable moisture and freezing temps. Epoxied rebar will last less, bare rebar less still and improperly installed epoxy rebar will last less than that. There are tons of 100yo buildings in fairly moist temperate climates with (poorly, by modern standards) reinforced concrete foundation that used bare rebar and are doing just fine.