FIRE DESIGN OF STEEL MEMBERS - Civil and Natural Resources ...

calculations made by the spreadsheet method give time temperature curves, which
are compared with the ECCS approximate formulas. There are no simple formulas
in the New Zealand Steel Code for protected members, as test data is relied on to
provide an estimation of the behaviour of protected steel members.
Properties of spray on protection: Fendolite by Firepro Safety Ltd
Specific heat, c i = 1100 J/kg K
Thermal conductivity, k i = 0.19 W/m K
Density, ρ i = 775 kg/m 3
Thickness, d i = 0.02 m
5.2.1 Results from a simulation with the SAFIR programme:
600
500
Temperature ( o C)
400
300
200
100
0
0 10 20 30 40 50 60 70
Time (min)
min ave max
Figure 5.1: Time temperature curve from a SAFIR simulation showing the variation of temperature
of different elements in the beam for four sided exposure to an ISO fire for a 530UB82 beam.
Figure 5.1 shows the variation of temperature across the cross section of the steel
beam. From examining the three SAFIR curves, it is found that the difference
between the maximum and minimum temperatures is greater than that found with
four sided unprotected steel, but less variation than three sided unprotected steel.
The maximum temperatures are found at the centre of the web, as the web is the
longest and thinnest section of the beam cross section. The coolest part of the
beam is the location of the centre of the flange, where the web and the flange
intersect. This is due to there being a larger mass in this part of the cross section
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