Further Progress in the Development of a Slug Calorimeter for Evaluating the Apparent Thermal Conductivity of Fire Resistive Materials.
Further Progress in the Development of a Slug
Calorimeter for Evaluating the Apparent Thermal
Conductivity of Fire Resistive Materials.
Bentz, D. P.; Gaal, P. S.; Gaal, D. S.
International Thermal Conductivity 29th
Conference/International Thermal Expansion 17th
Symposium. Proceedings. Chapter 8: Experimental
Materials. June 24-27, 2007, Birmingham, AL, DEStech
Publications, Inc., Koenig, J. R.; Ban, H.,
Editor(s)(s), 403-411 pp, 2007.
slug calorimeter; thermal conductivity; fire resistant
materials; equations; furnaces; experiments; heating;
cooling; temperature; test methods; computer models;
thermophysical properties; ASTM E 37.05
A new method for evaluating the apparent thermal
conductivity of fire resistive materials (FRMs) from
room temperature to 750 DGC using a "slug" calorimeter
was presented in 2005. The continued development of this
method is presented in this paper. A mini-furnace slug
calorimeter experimental setup has been designed,
constructed, and extensively employed to provide
apparent thermal conductivities of a variety of FRMs.
The development of an ASTM standard practice based on
this measurement method is being pursued within the ASTM
E37.05 Thermophysical Properties subcommittee. A
preliminary evaluation of the single laboratory
precision of the test practice has determined the
precision to be - 5 % below 500 DGC and less than 10 % up
to 750 DGC. While the original version of the
experimental setup employs twin specimens to produce an
adiabatic boundary condition at the central plane of the
steel slug, a single specimen version has recently been
developed that relies on extensive insulation to produce
an adiabatic boundary on the side of the steel slug not
in contact with the test specimen. Computer modeling has
been employed to demonstrate the validity of this
approach. These efforts are all part of the ongoing
"Performance Assessment and Optimization of Fire
Resistive Materials" NIST/industry consortium that was
initiated in March 2006.