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Rebar in contact with soil - gotta go?

Darren Emery

Registered User
Joined
Oct 20, 2009
Messages
501
Location
Manhattan, Ks
The vertical short bars stabbed in the ground are for chalk lines to guide the placement of wall forms. If the soil contact rebar was in contact with the horizontal bars - no question, it would come out. Wondering what others think of the presence of short rebar that will eventually rust out, but is not part of the true reinforcement?
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Well... I thought I had figured out how to post a pic, but apparently not! Is there a post that gives some guidance on how to upload a photo? Could not find anything in the website discussion thread.
 
as I understand it you need to be a Sawhorse to post a photo directly, workaround put in somewhere that has a link and post the link
 
When steel rusts it expands. That's not to say that it would cause the concrete in your case to crack. A single rebar probably wouldn't matter much other than an impalement danger. The rebars for strings are usually pulled out before the placement of concrete.
 
+ & +

Darren, ...in your photo it appears as though
the short pieces of rebar are indeed for the
string-lines.......IMO, the presence of "left
over \ non-removed material" indicates sloppy
work.......I would want them removed.

Are the 2" x 4" wooden forms
for a sidewalk ?

Also, ...if you would like to be able to insert
photos in to Thread Topics, I encourage you
to become a Sawhorse by starting a subscription
to this "most excellent" Forum.......Send Jeff a
P.M. for
payment options.

Thanks !

+ & +
 
+ & +

Darren, ...in your photo it appears as though
the short pieces of rebar are indeed for the
string-lines.......IMO, the presence of "left
over \ non-removed material" indicates sloppy
work.......I would want them removed.

Are the 2" x 4" wooden forms
for a sidewalk ?

Also, ...if you would like to be able to insert
photos in to Thread Topics, I encourage you
to become a Sawhorse by starting a subscription
to this "most excellent" Forum.......Send Jeff a
P.M. for
payment options.

Thanks !

+ & +

I don’t see a picture.
 
@ ! @

ICE Man, ...at the end of Darren's OP, there is an
image Link.....I clicked on it and it took me to his
photo.


@ ! @
 
Thanks for the input everyone. I appreciate Ty posting the pic, and I will re-join as a sawhorse soon. Was one of the original supports many moons ago - good to be back!
 
+ & +

Darren, ...in your photo it appears as though
the short pieces of rebar are indeed for the
string-lines.......IMO, the presence of "left
over \ non-removed material" indicates sloppy
work.......I would want them removed.

Are the 2" x 4" wooden forms
for a sidewalk ?



Thanks !

+ & +

The forms are for spread footings under foundation walls.
 
Darren's picture of the form boards for the footing is cause for my residential code question:

What is the maximum allowable space between the bottom of the concrete form and the ground?
 
Orange indicates "remove"?

No. In my area the soil is the same color as the rebar, so we paint the vertical bars so they don't get stepped on / tripped over.

I guess if we were in Cali., I'd have to write them up when they do that because there's no caps on top..
 
Darren's picture of the form boards for the footing is cause for my residential code question:

What is the maximum allowable space between the bottom of the concrete form and the ground?


Depends on how much concrete you want to waste..

There's nothing in the IRC I don't think. Maybe something in ACI 318?
 
Darren's picture of the form boards for the footing is cause for my residential code question:

What is the maximum allowable space between the bottom of the concrete form and the ground?

I don’t have an ACI book and it’s been moons since I’ve thumbed through, I do recall when I was ACI 1&2 certified prior to ICC the formwork was to be in substantial contact w the surface. I wouldn’t raise an eyebrow over a minimal gaps that won’t affect the overall sizing of the footing. And for residential most Crete for footings is poured stiff so the contractors can strip it soon after and move on.
 
We limit gaps to no more than 2 inches between the earth and bottom of the form. It was something we got from ACI 318 about the forms are required to constrain the concrete. 2018 IRC, Section 404.1.3.3.6 states the forms shall be approved material suitable for supporting and containing concrete.

I need to get a copy of ACI 332-14.
 
I do not have a problem with small rebar used as support - here is why. Corrosion is not a fast action unless the right conditions exist (oxidation). When you build large concrete structures (I have built footings that were 6' or more thick) you have form ties that are usually designed to shear off after removing the forms. I built concrete caps that encased driven steel piles. For exposed walls we usually rubbed the walls which would somewhat cover them) but to my memory we never did for the underground stuff. In another post of days past I posted about the fiber rebar that we now see. If that was used as support by being driven in the ground then I would likely let that go too.
 
As long as the concrete flowing under the bottom of the forms does not disturb the concrete within the forms it is not a code issues. If there is a concern about a specific extreme case ask the engineer.

With regards to pieces of metal embedded in the concrete that are also in contact with the ground I do not see a problem as long as they are not part of the required reinforcing. If this is not acceptable then you should prohibit metal chairs for the rebar buy those chairs have been used for years.
 
If this is not acceptable then you should prohibit metal chairs for the rebar buy those chairs have been used for years.
Actually, chairs than that used in most cases to hold the bottom mat above the ground, in most cases, either small plastic chairs or dobies are used for that Mat and chairs a use top of that hold up the 2nd mat.

Here's an example of each: https://www.whitecap.com/dayton-superior-214-plastic-ez-chair-64406#127652-132PEZ225/, https://www.whitecap.com/dayton-sup...Ch0VtwQJEAQYAiABEgLoPfD_BwE#CPD075-132CPD075/
 
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