Effects of Specimen Edge Conditions on Heat Release Rate.
Effects of Specimen Edge Conditions on Heat Release
Rate.
(1086 K)
Babrauskas, V.; Twilley, W. H.; Parker, W. J.
Fire and Materials, Vol. 17, No. 2, 51-63, March/April
1993.
Keywords:
heat release rate; cone calorimeters; fire models
Abstract:
When bench-scale specimens are tested for heat release
rate, it is generally of interest that the behavior of
the specimen simulate, as much as is possible, that of a
real-scale product performing in a real fire. A number
of issues have been raised recently by workers trying to
understand the optimal conditions of specimen
preparation and mounting. In the present study a large
number of materials were explored in the Cone
Calorimeter to determine the effect of edge conditions
and edge frames. It was found that by the use of an
insulated edge frame, heat release rate values can be
obtained which are slightly closer to expected true
values. The testing procedure, however, is
significantly more complicated. This makes the
insulated edge frame useful for collecting specialized
data for fire modeling, but not for conducting routine
reaction-to-fire tests. For routine testing use, it is
recommended: (1) that no edge frame needs to be used
unless the test specimen presents special difficulties,
such as due to intumescence; (2) that in those cases
where the use of the steel edge frame is found
necessary, the results should be reported on the basis
of an effective exposure area of 0.0081 m2. When
reported on such a basis, the heat release rate results
do not show a systematic bias, compared to results with
no edge frame.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899