Steel Beam Fire Rating Calculator

Calculate fire rating of a steel beam with composite concrete deck using 3-sided heating analysis per Eurocode EN 1993-1-2

Input Parameters

Results

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Fire Rating
min
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Critical Temperature
C
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Bottom Flange Temp at 60min
C
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Moment Capacity Ratio
%
Note: Composite beams with concrete deck benefit from 3-sided heating (top flange shielded) and the thermal mass of the concrete slab. This typically provides 10-20% improvement in fire rating compared to 4-sided heating of equivalent section.

Reference

Eurocode EN 1993-1-2 Section 4.2.4 Critical temperature: Tcrit = 39.19*ln(1/(0.9674*mu^3.833)-1) + 482 3-sided heating: Hp/A reduced ~15% for composite beams Deck thermal mass reduces top flange temperature ISO 834 fire curve: T = 20 + 345*log10(8t+1) Strength reduction ky,theta per Eurocode Table 3.1