Cooling intumescents

Steel stmctures should be protected by approved fireproofing treatment, eg, concrete or insulating, ie, intumescent or ablative materials untreated steel should be protected by some method of cooling, eg, a water-spray system. 

A wide range of intumescent epoxy coatings are available. These can be described as a mix of thermally reactive chemicals in a specific epoxy matrix formulated for fireproofing applications. Under fire conditions, they react to emit gases, which cool the surface while a low density carbonaceous char is formed. The char then serves as a thermal barrier. 

The study of the viscosity of intumescent systems appears, as a consequence, to be an important way to better understand the carbonization process. The data obtained from this technique agree and complement the results obtained during the examination of the chemical composition of the intumescent shield. Moreover, it has to be highlighted that, to the contrary of most of the chemical investigations of the carbonization process, this technique studies the material in situ whereas most of the charred chemical compositions are evaluated after combustion and cooling of the sample. 

The commercial coatings are tabulated in Table 1 with a description of the coating and the employed cooling mechanism. Most of the commercial fire retardant coatings selected for this work function by intumescence, in which the coating swells and forms a cellular protective layer upon application of heat. Commercial coatings were applied to the steel coupon substrate with a brush and permitted to cure according to the manufacturer s instructions. 

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