Response of High Performance Concrete to Fire Conditions: Review of Thermal Property Data and Measurement Techniques.
Response of High Performance Concrete to Fire
Conditions: Review of Thermal Property Data and
Flynn, D. R.
NIST GCR 99-767; MetSys Report No. 98-01-101; 139 p.
Sponsor:National Institute of Standards and Technology,
Available from: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
1-800-553-6847 or 703-605-6000;
Order number: PB99-140493
concretes; computer models; fire tests; heat transfer;
literature reviews; mass transfer; spalling; temperature
The NIST Building and Fire Research Laboratory (BFRL)
has undertaken a project concerning the effect of fire
on high strength concrete. Heating concrete to
sufficiently high temperatures results in water of
hydration being driven off, with a resultant
irreversible loss of concrete strength. In addition, it
has been observed that rapid heating of high strength
concrete can result in spalling of the concrete.
Computer models for prediction of temperature and pore
pressure distributions in heated concrete typically
include consideration of (1) mass transfer of air and
water by diffusion and by forced convection, conversion
of liquid water to vapor, and release of water of
hydration and (2) heat transfer by conduction, mass
diffusion, and forced convection. In order to make valid
predictions, the computer models require reliable data
as to the physical properties of the concrete. Mass
transport properties are being investigated by the
Building Materials Division. Thermal transport
properties, the subject of this report, are being
investigated by the Building Environment Division. The
present report addresses (1) identification of material
properties critical to prediction of heat and mass
transfer in high strength concrete at high temperatures,
(2) variation of the thermal properties with
temperature, pressure, and thermal history, (3)
examination of correlations between concrete composition
and thermal properties, (4) identification of
appropriate experimental techniques for determination of
the thermal properties of high strength concrete, (5)
identification of available equipment and testing
services for carrying out such measurements, and (6)
preliminary design of special equipment that needs to,
be constructed for measurement of the thermal
conductivity of concrete.