Making beams easier to fail.
Look for this in commercial and residential structures. The way that this beam is pocketed will allow it to fail much faster than normal.
As we all know, these beams support much of the center of the building with floor joists resting on them.
Steel will deform and twist and this beam will meet little, if any, resistance during a fire. I understand that a pocket of concrete will not keep this beam from dislodging, but it there is a reason for properly pocketing these beams.
Not to mention a small tremor or bump from equipment or remodeling can compromise the stability of the beam.
Just one more thing to keep an eye on when doing inspections, especially during construction.
Stay safe and be careful.
http://firefightersenemy.com