• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Rebar left exposed too long

jar546

jar546

Forum Coordinator
Joined
Oct 16, 2009
Messages
11,046
Location
Somewhere Too Hot & Humid
What is the standard that you hold people to when rebar sits exposed too long? This photo, for example is of a beachfront foundation that has been sitting for over a year exposed to the harsh elements of a beachfront environment.

IMG_2973.JPG
 
See ACI 318. Not sure of the section, but it actually permits a light coating of rust. In the case of the pictured, have the Special Inspector right it up (if there is one) and send it to the EoR for approval. If no engineer/special inspection, and you feel it is excessive, then have it wire brushed off.
 
Agree with Ty and Msradell,

ACI 318-95

Have a Special inspection, some rust is allowed and a special inspector can preform a test which in most cases require some brushing of loose material. Flaking of steel would be an issue IMO. There may even be some coatings that are allowed prior to the concrete pour.
 
I wouldn't accept it, but with if a Special Inspector wants to sign off on it, I would buy it.
 
The rebar in that pic is how it comes out on the truck in my neck of the woods. I can drive 6 blocks from here and take pics of piles and piles of it sitting outside on their lot right now if you like.

Excessive rust is bad, and actual metal flaking off the bar is worse, but that pic is not an example either. I'd check some random tie wires and if they don't break when I touch them, they're going to get an "OK to pour" on the inspection sheet.
 
Some Rust is okay
Section 12 of ASTM A 615-96a, "Standard Specification for Deformed and Plain Billet Steel Bars for Concrete Reinforcement," says that rust shall not be cause for rejection provided the weight, dimensions, cross-sectional area, and tensile properties of a hand-wire-brushed test specimen aren't less than the ASTM specification requires.

Section 7.4.2 of ACI 318-95, "Building Code Requirements for Structural Concrete," has a similar statement indicating that reinforcement with rust shall be considered satisfactory, provided the minimum dimensions (including height of deformations) and weight of a hand-wire-brushed test specimen aren't less than applicable ASTM specification requirements.
 
Mark Handler is correct.

If there is a question whether the rust is excessive the contractor might request the opinion of the structural engineer since there may still be enough steel to satisfy the code and the design. It might be cheaper to add some steel as opposed to replacing the rusted steel.

Fatboy why would you not accept it if it was in compliance with the code?
 
At first glance it appeared pretty ratty. After a relook, I would probably give tie wires a tug, see how much flaking occurred. Probably would be Ok......
 
Still need to clean the debris before placement on concrete
And I would like the bars cleaner... But not my circus not my monkeys
 
Most of the rebar has not rusted to the point of rejection.....but not all of it. I have no knowledge about the application but the grouping of the conduit raises obvious questions.
 
jar546 said:
Why exactly would the grouping of the conduit raise questions?
Click to expand...
Well the thing is...I'm not sure what this is. It has the earmarks of a floor of something. Something weak to begin with. The cluster is about 14" wide for a big weaker spot. Now if it is a floor of something, the conduit should be higher in the slab and not tied to the bottom rebar. The cluster effect shouldn't happen and tied to the bar....but like I said, I don't know much about this stuff.
 
The compression values maybe reduced, and may have been calculated.
You still have the tension of the continuous bars.
Structural engineer should review.
 
Individual electrical conduits in concrete are typically not a problem structurally. When the conduit diameter is large compared to the dimension of the concrete or when there are a lot of conduits spaced close together the engineer should probably be consulted. In my experience if there is at least 2 inches of concrete between the conduit in your typical slab on grade the conduit can be tolerated.
 
You must log in or register to reply here.
Top