Steel Designers Manual - TheBestFriend.org

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Steel Designers' Manual - 6th Edition (2003)
Fig. 34.10 Pre fire-protected sections awaiting erection
Application of intumescent coatings in the fabricator’s works before delivery
means that steelwork can arrive on site finished (see Fig. 34.10), eliminating a whole
trade on site. This reduces construction time and can cut overall construction costs.
Further information can be found in the Corus publication Off-site fire protection
using intumescent coatings. 9
34.6 Fire testing
Fire testing 1025
Fire resistance requirements are based largely on the Fire Grading of Buildings
report of 1946. 10 The fire-resistance periods refer to the time in a standard fire,
defined by BS 476: Parts 20 and 21, 11 that an element of structure (a column, beam,
compartment wall, etc.) should maintain:
(1) stability – it should not collapse under load at the fire limit state,
(2) integrity – it should not crack or otherwise allow the passage of flame to an
adjoining compartment,
(3) insulation – it should not allow passage of heat by conduction which might
induce ignition in an adjoining compartment.
The ‘standard’ fire time–temperature relationship defined in BS 476 is presented
in Fig. 34.11. Most attention (and cost) is directed at satisfying the stability (or
strength) criterion.