The use of a slug calorimeter for evaluating the thermal performance of fire resistive materials has been successfully demonstrated. Key components of the system include the use of a "sandwich" specimen to provide an adiabatic boundary condition at its central axis and the utilization of multiple heating/cooling cycles to provide information on the influence of reactions and convective transport on the computed effective thermal conductivity values. The results obtained in this relatively simple small scale test can provide valuable insights into the mechanisms through which the FRM protects the steel substrate in an actual fire.
The current experimental setup is now being modified to include an exhaust fume hood at the top of the furnace so that it may be applied to a wider variety of FRMs that emit organics as well as water and CO2. It is envisioned that further modifications to the experimental setup may be required to evaluate intumescents and other FRMs that undergo considerable changes in their dimensions during exposure to a fire.