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RE: Beam cast on masonry wall

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A belated reply to a message that appeared some time back. The message was:

"It is a common practice at some places to cast rc beams directly on walls 
and thus to do away with vertical props, although these beams are designed 
to span between columns. The masonry wall is, of course, not load-bearing 
and rests either on plinth beam below or on nominal foundation. The same
procedure is carried out for upper floors as well. The argument put forward 
in its favour is that even if the beams are allowed to deflect freely 
between columns, this will usually be good for the initial deflection due 
to the beam and slab self weights only, because the wall would be in place 
before finishes or partitions are laid  so that these loads would in any 
case would  be tranferred directly to the wall below. Also the long-term 
deflection due to creep etc. will also be taken by the wall below. The site 
may lie in seismic zone 2.
Comments are welcome.
M. A. Mufti"

It seems a case of clearly incorrect construction procedure to transfer the 
floor loads to infill masonry walls by pouring the beams directly over the 
said walls. The load-path assumed in the frame analysis must be respected, 
in any case. The argument referred to is illogical. In fact, we must ensure 
that, even under long-term deflections, no load should "spill over" to 
non-bearing elements.

Rizwan Mirza
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