Intumescent coatings used for the fire-safe design of steel structures: A review

The mainstream use of intumescent coatings for the design of fire-safe steel structures has fostered extensive research into the development of effective intumescent coatings and the assessment of their fire performance as thermal barrier to structural elements and materials. The research community has highlighted numerous challenges related to the current design framework based on standard fire resistance furnace testing and the current methodologies have been questioned due to its over-simplifications, limitations and uncertainties. In order to overcome these challenges, numerous research studies have proposed comprehensive approaches and methodologies to investigate the effectiveness of intumescent coatings exposed to a range of heating and fire conditions. This review covers the more recent developments in the field of fire testing and analysis of the fire performance of steel elements protected with intumescent coatings. Apart from the chemical formulation, the substrate boundary conditions, the applied coating thickness, the heating conditions and the fire test method appeared to be the key governing factors. All of them should be considered for a rigorous and systematic testing and design environment that allows the explicit quantification of the effectiveness of intumescent coatings. •Recent extensive research into the development of effective and reliable intumescent coatings and the assessment of fire performance.•Numerous challenges related to the current design framework and engineering design methodologies based on standard fire resistance furnace tests.•Several research studies have proposed comprehensive approaches and methodologies to investigate the effectiveness of intumescent coatings.•The effectiveness of intumescent coatings have been investigated according to different methodologies and using different experimental setups.•The substrate boundary conditions, the applied coating thickness, the heating conditions and the fire test method appeared to be the governing factors.