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

The properties of the protection applied to the beam in Firecalc are those of
Fendolite protection by Firepro, see Section 5.2 for these properties. Firecalc has
an option to give the moisture content of the insulation which SAFIR does not
include. For the purposes of this report, the moisture content of Fendolite has been
taken as zero to provide consistency between the results. The spreadsheet method
can cater for the effect of a high moisture content in the insulation by adding a
time delay term at 100 °C when the moisture in the insulation would be
evaporated.
The results from an analysis with the Firecalc programme gives the results in
Figure 5.15
Temperature ( o C)
1000
800
600
400
200
Spreadsheet
SAFIR
Firecalc
0
0 50 100 150 200
Time (min)
Spreadsheet Firecalc SAFIR with slab
Figure 5.15: Comparison between results from Firecalc, SAFIR and the Spreadsheet method for a
180UB16.1 beam with 20 mm heavy protection.
From Figure 5.15 the temperatures from the Firecalc programme are consistently
lower than those found from the spreadsheet method. The Firecalc programme
gives lower temperatures for this protection case, and if the moisture content had
been added as a feature, this would have an even bigger deviation from the
temperatures from the spreadsheet method. The spreadsheet does not model the
effects of a concrete slab, but when comparing the results from Firecalc with those
of SAFIR with a concrete slab, the temperatures from Firecalc are still too low. As
in Section 4.4.2, the properties of the concrete in the Firecalc programme are
unknown but it is assumed they are not significantly different from the properties
in SAFIR.
114