Concrete clear cover to reinforcement due to Fire Ratings 1

[IngeIvan]

Hello,

I have a 3 and 4 hr fire ratings in some electrical rooms, but can't find any information on clear cover to reinforcement on walls. Not in IBC code at least. Are there any references for this? Maybe it could be similar to columns? Didn't there used to be a prision that was clear cover = number of hours in inches?

 

[KootK]

Check out ACI 216.1.

As I understand it, walls do not have bar cover requirements related to fire because, unlike predominantly flexural members and heavily loaded axial members prone to buckling (columns), walls retain significant capacity even after the reinforcement is weakened by heat exposure. Perhaps one does not want to be standing behind an earth retaining basement wall during a fire. But, then, the fire protection in that case would technically be only for the benefit or the worms and voles on the dirt side of the wall. Humans are expected to remove themselves from the locations that have been actively set ablaze.

CRSI has a nice summary document here: Link