Apparent thermal conductivity approach at high-temperature measurements of porous materials

The apparent thermal conductivity approach for high-temperature investigations of porous materials taking into account moisture transport, convective and radiative modes of heat transport, phase-change processes and chemical reactions is presented. Methods for the measurement of apparent thermal conductivity as a material characteristic are analyzed. An example of the practical application of the approach is given, for a hybrid-fiber reinforced cement composite exposed to high temperatures up to 1000 °C. The aspects of the utilization of apparent thermal conductivity as a tool in an assessment of porous materials and their multi-layered systems exposed to high temperatures are discussed.