Effective thermal conductivity of fibrous fireproofing materials

The study of the protection performance provided by fibrous fireproofing materials asks for simple and reliable models for the description of their thermal behavior in accident scenarios involving industrial fires. This paper focuses on the development and validation of a physical model for effective thermal conductivity in highly porous fibrous materials used in industrial fireproofing applications. Unlike other literature models, that include several adjustable parameters, the proposed model mainly relies on physical and easily measurable properties of the material (void fraction, average fiber diameter, bulk conductivity of the phases, etc.). The model was validated against experimental data measured for three commercial passive fire protection materials. If compared with the models currently available in the literature, the proposed model shows a better correlation to the experimental data, especially at higher temperature, where radiation is the predominant phenomenon.