Development of alternative technologies for off-site applied intumescent coatings : final report

The overall objective of this collaborative project between Corus, ProfilArbed, Centro Nacional de Investigaciones Metalúrgicas (CENIM) and the Centre technique industriel de la construction métallique (CTICM) was to support the case for using steel in the construction industry for addressing a number of issues in the area of fire protection, particularly in so far as they affect the case for taking fire protection off-site. Firstly, a number of new resin chemistries were examined to promote development of the next generation of thin film intumescent coatings. A number of different generic resin systems were examined as binders for thin film intumescent coatings; these include epoxy, polyurethane and methacrylate systems. The properties of these new systems were evaluated using physical and small-scale fire tests. One formulation developed was tested in a large-scale tire test at CTICM and gave promising initial results. Secondly, tests were made to ensure that the coatings currently available are suitable for off-site application, particularly with respect to their durability over the limited periods when they would be exposed to the natural environment during storage and erection. Two commercially available coatings were examined in a wide range of natural and accelerated durability tests and by the use of Fourier transform infrared (FTIR) and thermal gravimetric analysis techniques. The two coatings showed very different performance levels despite being based on the same basic chemistry and resin type. Finally, some of the construction practices currently used were examined to determine if changes could be made in order to enhance the case for using off-site protected steel. The type of damage that occurs during a typical off-site intumescent coating project was assessed, as was the effect that the damage would have on the overall fire performance properties of the coated sections. The use of uncoated bolts was shown to be feasible as long as certain conditions were adhered to.