Deflection limit for steel beams supporting masonry partitions
Deflection limit for steel beams supporting masonry partitions
(OP)
It has been suggested that steel beams of floors supporting masonry partitions be designed for a service load vertical deflection limit of span divided by 500 or 600 or perhaps even more stringent, to minimize the possibility of the partition cracking due to beam deflection. This would be under specified live load plus load applied after the partition is built, as well as the self weight of the partition.
Where is that limit given? Is it in the National Building Code of Canada or its User's Guide, or CSA S16.1? I can't find it, but I don't have the latest versions here at home. Or if not there, then where? Perhaps in NRC notes or an American publication?






RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
To hawkaz - can you tell me which American Standard gives the L/600 or 0.3" (8± mm)?
Thanks.
RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
Thank you Retrograde. A good Table to have. Does the Australian Code or Commentary explain or give examples of what they mean by "where provision is made to minimize the effects of movement"? It seems rather vague. Would a deflection space between the top of the wall and the underside of the floor structure above be considered as provision to minimize the effect of movement? Would provision of horizontal joint reinforcement be so considered? Or do they mean the provision of vertical control joints in the masonry?
Also, is the self weight of the wall to be included in the calculation? It would seem from the wording "after the addition of the partition" that the self weight of the would not be included, but I think self weight generally would be included...this wording is, in my opinion, a problem with Canadian and American Codes/Standards as well(although I have not looked at all of them).
RE: Deflection limit for steel beams supporting masonry partitions
I pulled up ACI 530-11, it is now section 1.13.1.4.1, but I don't see the .3" limitation anymore (l/600 still applies)
RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
RE: Deflection limit for steel beams supporting masonry partitions
ok, thanks very much hawkaz.
RE: Deflection limit for steel beams supporting masonry partitions
I've always included it in new builds. However, in an unshored application where a non-bearing wall above will be constructed quickly in one go, I think that you could make an argument for excluding the weight of the block. I think that you're only really interested in curvature that develops after the mortar sets.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Deflection limit for steel beams supporting masonry partitions
Mike McCann, PE, SE (WA)
RE: Deflection limit for steel beams supporting masonry partitions
Whatever the final stl. beam deflection, you might consider making the bottom couple courses of the conc. blk. wall a horiz. reinforced masonry beam. Make the bot. course out a bond beam blk. with some rebar. Fill the next course of regular blk. with grout also, and put some joint reinforcing in several of the lower joints. This will help the whole wall act as a deep beam, and do some of its own spanning was the stl. bm. starts to deflect. It will also inhibit any cracking from the bottom of the blk. wall due to the stl. bm. deflection. It will relieve the blk. wall loading on the center portion of the stl. bm., as the stl. bm. starts to deflect.
RE: Deflection limit for steel beams supporting masonry partitions
ok.
And thanks dhengr for the good idea. Much appreciated.
RE: Deflection limit for steel beams supporting masonry partitions
The Code does not elaborate but generally I would consider both provision of horizontal joint reinforcement and the provision of vertical control joints are acceptable.
Normally I would include the weight of the partition in the calculation.
RE: Deflection limit for steel beams supporting masonry partitions