Temperature evaluation in steel fire protected elements with intumescent coating

The heat transfer analysis plays an important role in the temperature prediction of insulated steel members exposed to fire conditions. Based on the results of a previous experimental work, made in intumescent-coated protected elements, the intumescent effective thermal conductivity temperature variation was estimated. An analytical approach, based on the one-dimensional heat transfer parabolic partial differential equation through the insulation, considering a nonhomogeneous (time-varying) boundary condition at fire interface and a lumped capacitance at the insulation-steel interface, is presented. Solutions are established with temperature independent thermal properties and then extended to temperature dependent thermal properties. These solutions are compared with numerical results performed by finite element method using Matlab for different values of insulations thicknesses and steel section factors