Concrete Beam Connection to Steel Column

[PEinVA]

I have a slab that is being repoured and in one section I have to attach a 12" x 24" beam to a the flange of a W12x53 column. Any suggestions? I've already asked my boss to use a single shear plate with some shear studs on either side, with the amount required to transfer required shear, but he'd like some other ideas.

Another thought is put some embed plates on either face and remove small portion of formwork at end of beam and weld plates to the column.

Anyone have any details for this type of connection?




RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[WillisV]

Weld some deformed bar anchors to the steel column and lap them onto the beam reinforcing:

http://www.nelsonstud.com/Portal/Portals/0/pdf/Catalog/StudWeld/ConcreteAnchors/D2L.pdf

 

[PEinVA]

How does that help to transfer shear? Similar to a shear stud? Also I'm worried about creep and fatigue failures.

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[csd72]

make a concret corbel out of a W section and fit that indis the shear links. Transfers shear via bearing on top.

Can your column take the additional moment due to end restraint?

 

[lkjh345]

Can you weld an angle (stiffened if need be) onto the face of the steel column to provide a bearing surface for the concrete beam?

One step further might be to cast a embed plate into the bottom of the concrete beam (much as a precast concrete supplier would do), let the CIP concrete go through intial curring and shrinkage, and weld the embed plate to the seat angle 30 or 60 days after casting the concrete.This would relieve some of the shrinkage problems.

 

[JAE]

I'd second the seat idea. You could create a "U" shaped saddle that is welded to the steel column and the concrete beam could be formed into it.

You could add some headed anchors as well to tie the two together. The saddle would take 100% of the vertical shear load. Then you could weld deformed bar anchors to the column and extend them into the beam to develop any horizontal tension load that would occur.

 

[youngstructural]

This probably won't help you, but you never know...

Is there a threaded deformed bar product available where you are? I would use Reid bar and simply drill top and bottom steel into the existing column (having first checked that the reduced section isn't of concern). This done, box up and lap onto the "starters". Very similar to the nelson stud idea, only easier.

Check out

http://www.reids.co.nz/

Cheers,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...

 

[structuresguy]

I would also use some kind of bucket. Also, unless I really need a moment connection at the end of the concrete beam, and designed my column to handle said moments, I would try to avoid using headed studs or DBA's welded to the column flange face. If there was any chance of axial load, I would only use studs/DBA's located below the neutral axis of the beam, to try to limit any moment generation.

Otherwise, with a bracket or bucket formed on the column, you can treat like pinned connection, particularly if you add neoprene bearing pad. Only moment would then just be from load eccentricity.

 

[youngstructural]

I've only done this once, and as such really like reading other people's opinions and views of potential pitfalls.

Please correctly if you believe I am wrong, however, IF you've got a existing column that was sized for a beam framing into the "far" side, and you now add a concrete beam to the "near" side, you've actually improved the behaviour of the column, n'est pas? This, of course, requires a check of the newly increased compressive load and actions on all supporting structure (including foundations), but fundamentally the local behaviour of the column should be improved... There is no way to discuss the overall system in general and I do not try; Just thinking about the column itself.

What do you think?

Cheers,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...