Slug Calorimeter for Evaluating the Thermal Performance of Fire Resistive Materials.
Slug Calorimeter for Evaluating the Thermal Performance
of Fire Resistive Materials.
(213 K)
Bentz, D. P.; Flynn, D. R.; Kim, J. H.; Zarr, R. R.
Fire and Materials, Vol. 30, No. 4, 257-270,
July/August 2006.
Keywords:
fire resistant materials; calorimeters; thermal
conductivity; ASTM E 119; equations; experiments;
insulation; temperature; small scale fire tests
Abstract:
The utilization of a slug calorimeter to evaluate the
thermal performance of fire resistive materials (FRMs)
is presented. The basic specimen configuration consists
of a 'sandwich', with a square central stainless-steel
plate (slug) surrounded on two sides by the FRM. This
sandwich configuration provides an adiabatic boundary
condition at the central axis of the slug plate that
greatly simplifies the analysis. The other four (thin)
sides of the steel plate (and FRM specimens) are
insulated using a low thermal conductivity fumedsilica
board. Two metal plates manufactured from a high
temperature alloy provide a frame for placing the entire
sandwich specimen slightly in compression. The entire
configuration is centrally placed at the bottom of an
electrically heated box furnace and the temperatures of
the metal slug and exterior FRM surfaces are monitored
during multiple heating and cooling cycles. Knowing the
heat capacities and densities of the steel slug and the
FRM, an effective thermal conductivity for the FRM can
be estimated. The effective thermal conductivity of the
FRM will be influenced by its true thermal conductivity
and by any endothermic or exothermic reactions or phase
changes occurring within the FRM. Preliminary tests have
been conducted on two commonly used FRMs and on a
non-reactive fumed-silica board to demonstrate the
feasibility of the method.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899