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Further Progress in the Development of a Slug Calorimeter for Evaluating the Apparent Thermal Conductivity of Fire Resistive Materials.


pdf icon Further Progress in the Development of a Slug Calorimeter for Evaluating the Apparent Thermal Conductivity of Fire Resistive Materials. (219 K)
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.

Keywords:

slug calorimeter; thermal conductivity; fire resistant materials; equations; furnaces; experiments; heating; cooling; temperature; test methods; computer models; thermophysical properties; ASTM E 37.05

Abstract:

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.