×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Slab wall connection (rebar join) options

Slab wall connection (rebar join) options

Slab wall connection (rebar join) options

(OP)
A reinforced concrete wall is poured, allowed to cure, then a reinforced concrete floor slab is poured.  The rebar in the slab must be joined to the rebar in the wall.  If protruding bars need to be avoided, what methods may be used to join the bars?  I have already considered
1) Couplers recessed or embedded in the wall
2) Covered pre-bent bars
Can anyone suggest other options?

RE: Slab wall connection (rebar join) options

AtomicRob,

If the wall vertical rebars are small (#4 or #5) they could be extended, projecting straight up above the joint.   Normally, vertical rebars do not interfer with the forms.
After the concrete is set and has reached some strength, the rebars could be bent in place without damage to the concrete.   

When using threaded couplings the bent bar has to be turned, interfering with the adjacent bars.

RE: Slab wall connection (rebar join) options

Rob,

From my reading of your post the new floor is not necessarily being poured so as to rest on top of the wall as is the case where DLew has provided an option.  So if this new floor has to be poured adjacent to an existing wall another option in addition to the embedded couplers is to use epoxy or polyester based adhesives.  While this is more expensive than the embedded couplers, it does allow for accurate placement of the bars once the forms are removed.

If you have any doubts about the quality of the contractor to be used (and his field surveyor) you might be safer planning on epoxy from the start.  The other side of the argument is that the contractor will have to pay for the epoxy embedment if he screws up the coupler placement, but you still might end up seeing the couplers above or below a slab.  And then you have a choice of visible rusty (eventually) couplers or an ugly patch.

If this is a large job with an established contractor and good superintendent and surveyor, the couplers will probably be placed ok.

Good luck,

Jim

RE: Slab wall connection (rebar join) options

(OP)
Thanks Jim and Dlew for your responses.  (FYI: Yes, the floor slab is to be poured adjacent to an existing wall, as opposed to on top of it - sorry, I should have specified).

I have also recieved the suggestion that the rebar could be welded directly to an embedded steel plate in the wall - any thoughts on that (pros, cons, potential problems, etc.)?

Rob

RE: Slab wall connection (rebar join) options

I don´t think properly welding rebar to a plate should be much cheaper than using mechanical or adhesive insets. In any case if you go for it a relatively thick plate (over half the diameter thick) should be used, AND complete warrant of the weldability of the used rebar steel is required, since some rebar used for steel change for the worst their mechanical properties upon welding (be it upon then acquired fragility or loss of strength) that you can't count it as normal and reliable reinforcement.

RE: Slab wall connection (rebar join) options

Rule of thumb is to never weld rebar.

RE: Slab wall connection (rebar join) options

And heres the rest -
Instead, weld A36 threaded rods or the like instead of rebar.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources