Steel Beam to Masonry Wall Connection - Beam Pocket Grouted Solid

[Echo26]

For a steel beam connection to masonry wall, it seems that the standard practice is to have an embed plate in a beam pocket in the masonry wall and the pocket grouted solid. At the roof level, what is the purpose of grouting the beam pocket solid? Are there any structural implications or is it mainly architectural?

 

[BAretired]

The top of beam should be laterally braced at the support. Grout would provide that.

BA

 

[Echo26]

Thank you for your response BA!

Wouldn't the steel deck be laterally supporting the top of the beam?

 

[phamENG]

At unframed ends of beams and girders not otherwise restrained against rotation about their longitudinal axes, a pair of transverse stiffeners, extending the full depth of the web, shall be provided.

It's not just the top flange being restrained laterally, it's the entire section being restrained torsionally.

 

[BAretired]

I'm not sure how to interpret the requirement cited by phamENG. If the top flange is deemed to be laterally braced, and if the bottom flange is bolted to the wall, then, it seems to me that the beam is restrained against rotation at the point of bearing.

Perhaps the correct interpretation is that if the top flange is completely unrestrained against rotation, a pair of stiffeners is required; in which case the attachment to the wall must be capable of providing rotational restraint.

BA

 

[Echo26]

BAretired, so would you say grouting of the beam pocket solid isn't necessary if you have the steel deck laterally supporting the top of the beam?

 

[phamENG]

Echo,

Take a look at Appendix 6, stability bracing for beams and columns. Beam Bracing, 2. Torsional Bracing. As long as you can justify a load path with that strength and stiffness, you'd be fine.

But why bother? If anything goes wrong at the beam end and it's not grouted solid, have you upheld the standard of care? Since it would be really easy to get any number of engineers to say they would have done it, it's likely that it would be determined that you did not. It's also easy and not putting it on the drawings is likely to draw an RFI from a good contractor (who expects to see it there).

 

[BAretired]

BAretired, so would you say grouting of the beam pocket solid isn't necessary if you have the steel deck laterally supporting the top of the beam?

Yes, I believe so, but adding grout in the beam pocket is not a significant cost, so I believe it is prudent to specify it on the contract documents for the reasons given by phamENG.

BA

 

[Echo26]

Thanks guys!

phamEng, I actually have the beam pocket grouted solid in the drawings and got an RFI from the contractor to anchor a plate to the wall instead of grouting the beam pocket solid. They're claiming it will help with schedule and subtrade availability and that it is expensive and they are out of budget. I declined the proposal as it was tendered with the pocket grouted so I responded to keep the pocket grouted solid as per drawings and that it is for torsional stability/rolling resistance of the beam. They're claiming that grouting is mainly for aesthetics. I was a little bit in awe so I posted the thread. I'll take a look at Appendix 6 as referred and hopefully this will shed some more light.

 

[phamENG]

Unless you are in an area with some strange trade/union rules (ran into that on a government job I did in California once - flipped some of the project economics I was used to on their head), most contractors I know would take a laborer with a bag of grout and a trowel over extra steel fabrication any day. But each project, region, and team have their own quirks.

 

[dold]

RFI from the contractor to anchor a plate to the wall instead of grouting the beam pocket solid.

Contractor was probably trying to avoid having to deliver fabricated steel before/while the masons are building the wall? The actual act of grouting probably wasn't the issue. Bolting a plate to the face of wall is more off-the-shelf and can be done any time prior to steel erection.