Masonry wall reinforcement 5

[kschulte]

I am designing an interior non-bearing masonry wall bearing on steel beam. This wall is technically not part of the Seismic resisting system and will be isolated at 3 sides in plane of the adjacent walls and roof. I am in the process of checking to see if it can be unreinforced. If so, will stud anchors welded to the top of the flange and grouted in the cells at 16" capable of keeping the wall in place? Any input is greatly appreciated.

 

[jjeng2]

Provided the wall is not going to be taking any lateral loads and is non load bearing.....

BOCA used to have a table and I believe it is now in the IBC that lists the maximum spans you can go unreinforced with a certain thickenss masonry wall. I would use that as your guide. Is it sitting on a slab or directly on the steel? I would weld rebar to the top of the steel or have rebar bent into the slab and grout solid at bottom two courses. I like to brace the top of the wall also. Put a continuous bond beam at the top course and make a lateral only connection to whats above. Allow for vertical movement. If there is steel above, weld a continuous or clip angles to steel and hilti into bond beam.

 

[whyun]

Sort of difficult without the code adopted by the jurisdiction where the project is; however, minimum reinforcement (vertical and horizontal) should always be satisfied. Even non-bearing, non-lateral-force-resisting walls will experience stresses due to its own weight. If the wall is unrestrained at the top, you must treat this like a fence wall and design for the vertical reinforcement.

As for solid grouting all cells or partial grout, it depends on the local requirements. For example, City of LA allows partial grouted cells where as California Building Code requires that all cells be grouted.

 

[FalsePrecision]

Regardless of what the Code may allow, I would also (in addition to jjeng's input) specify #4 verticals at 48" oc, match/lap with the dowels to steel beam or slab. I don't know the whole situation, but be very careful of stability during construction.

 

[SperlingPE]

Not knowing code, there is a 5 psf minimum lateral load for interior walls. Put minimum reinforcing in and support top of wall if possible.

 

[JAE]

You don't always have to have the wall reinforced. If it is interior - and the 5 psf is the only lateral load - then many times a non-reinforced wall works fine for simple partitions. This is simply covered in the non-reinforced section of ACI 530. If the max masonry stresses don't work out, then of course reinforcing would be required.

 

[jjeng2]

I am conservative all the time but I dont think Ive ever reinforced an interior non-load bearing masonry partition wall. But my motto is...if the client dosent mind id prefer to sleep better at night.

 

[jhall]

I have done a very similar detail. I had a weldable rebar welded to the top of the beam. Make sure that you watch the deflection of the support beam.

 

[whyun]

JAE,

I hope your comment is for areas in non-seismic zones. In California, non-bearing CMU partitions will experience lateral force far exceeding 5 psf. Would you reinforce the walls in this condition?

I haven't practiced outside California too often, so I wouldn't know what's required in non-seismic zones.

 

[kschulte]

The location of this project is in Pennsylvania. Thank you all for your input.

 

[JAE]

whyun - yes, I would agree totally with you - as my post above stated, if its only the 5 psf (in non-high-seismic regions) then I would consider non-reinforced.

In all cases, I apply the requuired loads, and if a non-reinf. doesn't work, I reinforce it. I have done some projects in CA and ya...the lateral is pretty high there for some odd reason. You got big moles out there?

 

[whyun]

1997 UBC is what changed it all around here, with the introduction of near source factor. Areas far enough away from type A or B faults are comparable to the 1994 UBC level forces but most of the "populated areas" get some sort of penalty for being too close to the fault...

I am waiting for California adoption of the IBC so I can actually "learn" the new code that's been around for 5 years.

 

[haynewp]

I don't have my IBC with me right now, but I think for even moderate (SDC C) categories cmu partition walls are required to have reinforcing whether it is shown to be required by analysis or not.