Experimental study on thermal resistance of intumescent coatings
General information
Project type: Project funded by COWI Fonden (245000 dkk, September 2013)
Time frame: January - September 2014
Keywords: Intumescent paint, thermal resistance, fire lab, oven, radiant panel, FO room
Contacts: Grunde Jomaas
Luisa Giuliani
Project description
Motivation: It is widely recognised that the thermal properties of intumescent coatings (Fig.1) do not depend only on temperature, but are also affected by other properties of the fire, such as flame exposure, heat flux and fire growth rate [1]. However, current design methods for insulation of steel elements consider the standard fire curve as sole thermal action [2]. As a result, they cannot ensure with sufficient reliability the desired performance in a real fire.
Purpose: The project aims at investigating the effect of different fire conditions on the equivalent thermal resistance of intumescent coatings. The results of the tests will be used for the development of a simple but more accurate method for designing insulated steel members.
Method: Small and medium scale steel samples protected with intumescent coating will be tested under different fire conditions in the DTU Fire Lab. Three different sets of experiments are envisaged (Fig.2): in the first, the samples will be tested in an oven; in the second, the samples will be tested under different intensity levels of the incident radiation from a radiant panel; in the third, the samples will be exposed to natural fires in a small flashover room.
Results: The outcomes of the tests are expected to highlight the sensitivity of the thermal inertia to the different fire conditions and allow for the development of experimental formulas or design tables for the assessment of the equivalent thermal inertia.
Essential literature
[1] M. Bartholomai and B. S. R. Schriever, “Influence of external heat flux and coating thickness on the thermal insulation properties of two different intumescent coatings using cone calorimeter and numerical analysis,” J. of Fire Materials, vol. 27(4), pp. 151-162, 2003.
[2] ISO834-1, Fire resistance tests - Elements of building construction - Part 1: General requirements for fire resistance testing, Geneva, Switzerland: International Organization for Standardization (ISO), 1999.