Experimental study of epoxy coatings for fire protection of bridge cables

ABSTRACT An experimental study on the performance of epoxy coatings exposed to different fire conditions was undertaken in order to assess if such paints could be a viable passive fire protection solution for bridge cables. Epoxy paints are of interest for this application due to their high resistance to environmental agents and the capability of resisting hydrocarbon fires. However, recent studies have shown that the performance of water‐ and solvent‐based intumescent coating are strongly affected by the fire condition, and particularly the heating rate, and it is essential to assess if these challenges are also present for epoxy paints. Therefore, two different epoxy coatings were applied to small steel plates and exposed to different constant heat fluxes ranging between 20 and 80 kW/m2 in a cone heater. The results of the experiments are presented in terms of expansion of the coating, temperatures of the substrates and efficiency of the coating, calculated as relative difference between the temperature of an uninsulated sample and a sample coated with the coating. The outcomes of the experiments indicate that there is a dependency between the incident heat flux and the char development and thus the ability to protect the substrate.