×
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

new beam to existing column

new beam to existing column

new beam to existing column

(OP)
i'm currentls working on a project where we need to put a new beam to connect to an existing column. what are the ways to place a new RC beam to an existing RC column?

RE: new beam to existing column

Does it have to be a RC beam?  Can you use a steel section?  If you can use a steel section the connection becomes easy.  If you must use a RC beam, try using epoxy for the bars into the column.  Make sure the embedment is long enough to develop Fu of the bars and use shear friction to get the load into the column.  I would also shot blast the column face where the beam will attach to roughen the surface to get a higher coefficient of friction.

RE: new beam to existing column

(OP)
unfortunately, yes, it has to be a RC beam. what if the column is too narrow to develop the Fu of the bars by using epoxy? is there any other way to connect the beam to the column?

RE: new beam to existing column

Is it to one side or two opposite sides?

RE: new beam to existing column

What are the column dimensions?  What are your beam dimensions and what forces do you need to dump into the column?

RE: new beam to existing column

Lot of unknowns here. Why can you not use steel or a steel
bracket? Is it a fire rating issue?

RE: new beam to existing column

You could use a steel bracket to make a simple support. But you need to check the column for bending due to the eccentricity (V*e).

RE: new beam to existing column

#6 rebar with hilti adhesive only need 6" emb to develop tensile strength for 4000 psi concret. 4" emb to develop yield.

 

RE: new beam to existing column

Depending on the size of the column, edge distances might be a killer. There are a lot of unknowns as mentioned before.

If the column is fairly small, it might be better to drill through completely and run continuous rebar and fill with epoxy. That way, there are no concrete failure modes to worry about. Shot blast the surface as SEIT suggested.

RE: new beam to existing column

gggaa,

Are you out there somewhere in cyberspace?

RE: new beam to existing column

Provide a sketch.

BA

RE: new beam to existing column

When I have this problem, I just look for a place to put another column.  If the existing column was intended to support another concrete beam, it should have had provisions for the connection.

RE: new beam to existing column

You could look at removing all the column concrete for the depth of the beam, tieing in the beam rebar and pouring back as part of the beam. Precast columns can be done by this method.

Any load on the column will have to be temporarily resupported.

RE: new beam to existing column

(OP)
here's a sketch of the beam's location and the dimensions. i apologize if the sketch isn't much help, since i'm new at this.

right now i'm leaning towards making a new column to support the beam, since i don't know if the existing column was designed to carry the load of the new beam.

http://files.engineering.com/getfile.aspx?folder=aafd33ad-ce9e-4fce-a86e-5b7feafa6b50&file=img042.jpg

RE: new beam to existing column

I think that gggaa must be lost in cyberspace.

RE: new beam to existing column

6" x 16" is a pretty slender column.  If you can add a new column and support it at foundation level, that would likely be the best solution.

BA

RE: new beam to existing column

Assuming this is only a single storey addition, just adding another 6" to the existing column should do the job, provided the footing is capable of carrying the load.  Provide enough drilled in anchorage to tie the two parts together.

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