Heat and Mass Transfer Model for Fire-Exposed Concrete—Part A: Validation of Temperature and Pressure Predictions

Explosive spalling of concrete is an essential phenomenon to be accounted for when analyzing the fire performance of concrete structures. Existing fire simulation tools can provide the fire exposure on the concrete surface and to some extent, conjugate heat transfer, too, but new tools are needed to model concrete high-temperature reactions coupled with heat and mass transfer. This work forms the first part of the two-part work. In Part A, we formulate a one-dimensional heat and mass transfer model to predict the internal temperature and gas pressure and verify the solver implementation using analytical solutions. Model validation is performed using experimental data for normal moisture from the research literature. In the absence of concrete chemistry details, the degradation reactions are calibrated using the measured mass loss histories, reaching a post-calibration uncertainty ≤ 0.4%. The validation results indicate that the maximum mean absolute percentage error (MAPE) for temperature predictions is ≤ 16%, bias = − 2.4% and relative standard deviation 9.1%. For the peak pore pressure, 57 ≤ MAPE ≤ 87%, averaged over depth and ignoring outliers and singular measurements. Possible reasons for the high pressure uncertainty are discussed.