How is the critical temperature of structural steel affected by fireproofing? What temperatures can fireproofed structural steel withstand?
mix the fire retardant with cement, let it harden fast to superstructure. this will create better stability and will not be dislodged in case of impact.
This would depend upon the method of fireproofing. Steel used to be insulated with an asbestos coating. Of course the steel under the insulation had the same critical temperature as the uncoated steel but was protected from external heat by the insulation. More commonly it would be an alloy and there are so many that one could not guess except to say it should be higher than the original.
I didn't know they fire proofed steel. Usally they would just use a steel with a higher melting point.