Assess the Fire Resistance of Intumescent Coatings by Equivalent Constant Thermal Resistance

Abstract

Intumescent coatings are now the dominant passive fire protection materials used for steel construction. Intumescent coatings will react at high temperatures and the thermal properties of intumescent coatings can not be measured directly by the current standard test methods which are originally designed for the traditional inert fireproofing materials. This paper proposed a simple procedure to assess the fire resistance of intumescent coatings by using the concept of equivalent constant thermal resistance. The procedure is based on the approximate formula for predicting the limiting temperatures of protected steel members subjected to the standard fire. Test data from investigations on both small-scale samples and full-scale steel members are used to calculate the equivalent constant thermal resistance. Using the equivalent constant thermal resistance of intumescent coatings, the calculated steel temperatures agree well with the test data in the range of the limiting temperatures from 400°C to 600°C. The procedure needs no complex computation and is recommended for practical usage. The equivalent constant thermal resistance could be used to quantify the insulation capacity of intumescent coatings.

Correlating the Performance of a Fire-Retardant Coating across Different Scales of Testing

“…Apart from the above, there are publications relating the data from different polymers with rapid mass calorimeter, cone calorimeter, and PCFC [ 11 , 12 ]. More importantly, from the context of this manuscript, there are also many publications on different fire-retardant polymer-based coatings on small steel panels [ 13 , 14 , 15 , 16 ], some [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ] of which use a bulk-scale test setup to evaluate the performance of intumescent coatings. Bulk-scale test involves the use of a coated substrate and the amount of materials involved is typically measured in grams.…”

Effects of substrate thermal conditions on the swelling of thin intumescent coatings

“…New ingredients and compounds are added and the swelling reaction is analysed in terms of mass loss (Thermo-Gravimetric Analysis, TGA), calorimetry (Differential Scanning Calorimetry, 3 DSC) or spectroscopy (Fourier-Transform Infrared spectroscopy) [10][11][12][13] . On the contrary, within fire safety engineering practice, the insulating performance of intumescent coatings is usually assessed at medium and large scales using different experimental methodologies, such as cone calorimeters or furnaces of various sizes [14][15][16][17][18][19] . These experiments mainly focus on measuring the temperature evolution of coated samples and this parameter is adopted as main performance criteria (i.e.…”

Optimal Fire Design of Steel Tapered Portal Frames

“…Thus, no closed formula exists to calculate the temperatures of a steel plate. In this study, the iterative algorithm of [15] is adopted in the algorithm and the necessary so-called equivalent constant thermal resistance [25] is calculated based on an ECCS (European Conventions for Constructional Steelwork) recommendation [26,27] and on data given in the design sheet [23].…”