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

To examine the limits of the thickness of the insulation, this section uses thicker
insulation. The insulation type is Fendolite, as used in Section 5.2. This insulation
is considered heavy and has thermal properties as below:
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
5.5.1 Results from a Simulation in the SAFIR programme:
1000
Temperature ( o C)
800
600
400
200
Spreadsheet
SAFIR results
0
0 50 100 150 200
Time (min)
min ave max Spreadsheet
Figure 5.9: Maximum, average and minimum temperatures found from a SAFIR simulation of a
530 UB 82.0 beam exposed to the ISO 834 fire on 4 sides, with 40 mm heavy protection
Figure 5.9 above shows the variation of temperature across the cross section of the
steel section with time. The temperature of the steel is almost constant across the
cross section of the beam during the fire test. Comparing the difference between
the maximum and minimum temperatures found in SAFIR with thick protection
from Figure 5.9 with those with thinner protection from Figure 5.1 highlights how
the thicker protection slows down the heating of the steel. The temperature of the
steel reaches 500 °C in around 60 minutes when 20 mm of protection is applied to
the 530UB82.0 beam, but it requires around 100 minutes to reach this temperature
when 40 mm of protection is added.
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