I need to build a CMU wall, startin

[Hercul3s]

I need to build a CMU wall, starting on a steel beam. Can anyone tell me what is the best way to connect/start my vertical steel on the beam top flange? (Vertical rebar running in CMU cells).
Should I just weld the rebar to the beam? Thanks!

 

[darthsoilsguy2]

that is 1 way to do it... require the steel beams to have shop-welded DBA's. google "dba welding". Another approach i have seen is to have the beam come with studs shop-welded to it and have the 1st course be a bond beam that engages the studs and hook the verts into for the wall above.

 

[Hercul3s]

Great! Thanks darthsoilsguy2!

 

[KootK]

If you do the rebar thing, do it by welding couplers onto the beam in the shop and then threading the rebar/dba into the couplers on site. Having the rebar welded to the beam in the shop can make things difficult for shipping and erection safety.

If you can live with a shear only connection between block and beam, and usually you can, I very much prefer darth's nelson stud concept. I wouldn't even bother hooking the wall verts or attempting to place them near the studs. It's pretty much impossible to coordinate your studs (or rebar) to reliably land where you want them in the masonry cells. There's an excellent chance that the masonry close to the beam is going to have to be all broken up internally to accommodate the connection. So, in my opinion, it's best to use the studs and get the pain over with as quickly as possible in a single bond beam course.

HELP! I'd like your help with a thread that I was forced to move to the business issues section where it will surely be seen by next to nobody that matters to me:

http://www.eng-tips.com/viewthread.cfm?qid=456235

 

[KootK]

It seems to me that your best, next step for extracting value from this thread is to propose some scaled connection details for how you think that you might get this done the way that you want to. Rest assured, we'll be standing by, happy to eviscerate whatever you come up with.

HELP! I'd like your help with a thread that I was forced to move to the business issues section where it will surely be seen by next to nobody that matters to me:

http://www.eng-tips.com/viewthread.cfm?qid=456235

 

[JLNJ]

I'm with KootK in that I spec nelson studs and don't worry about anchorage of the vertical rebar. Put the studs at a multiple of 8" on center and specify a beam wide enough that the grout doesn't leak out around the cores. Definite evisceration for specifying a 4" or 5" wide beam.

I suppose you could have some sort of a weird supported shear wall anchorage situation where the rebar is seeing net tension and needs to anchored. This would take some extra thought and detailing.

 

[Ron]

Shore the beam before you start. Use DBA of sufficient length to develop the vertical bar lap, assuming the wall is picking up reasonable lateral load. Nelson studs are an easy field option, just make sure they are long ones (I would use 12" length).

Check the flanges of your beam for rotation under lateral wall load. You might need gussets.


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[Hercul3s]

Great! Thanks guys, for your help!