How Much Rust Is Too Much Rust? Rebar Edition

[jar546]

This is an SFR on the beach. How much rust is too much when it comes to the structural steel inspections before concrete is poured?
There are portions (not in the photo) that must have been left exposed for weeks that are in pretty bad shape.

 

[steveray]

I don't know that there is great guidance but....

 

[tmurray]

What I have heard (from a structural engineer) is that you need to clear all the loose rust off with a wire brush. Surface rust is not a big deal, but if you don't clear the loose rust off, if can inhibit the bond forming between the rebar and the concrete.

 

[Yankee Chronicler]

My understanding is that light surface rust is not a problem. If the rusting has progressed to the point that rust flakes or chips off when tapped with a hammer, the rebar has been compromised and should be replaced.

Ultimately, if there's any question the engineer-of-record should be required to look at the steel and issue a report.

 

[ICE]

if there's any question the engineer-of-record should be required to look at the steel and issue a report.

Has anyone ever done that? If you’re to the point of hitting the rebar with a hammer to see if chunks fall off, that rebar is compromised.