Passive fire protection of metallic structures

Abstract

This study evaluates the different approaches of Passive Fire Protection (PFP) on aluminium and steel. The first investigation determines effectiveness of newly developed multi-layer laminates made of aluminium, titanium and stainless steel foils insulating aluminium plate. This new means of fire protection is lighter than conventional flame retardant materials, such as intumescent coatings. Fire tests were conducted using a propane burner to provide 35 and 116 kW/m2 constant heat flux on the samples with and without loading. Results show that laminate with titanium and stainless steel as front face gives better protection against fire compared to aluminium in vertical orientation testing. The second studies focus on steel substrate temperature profile simulation using two newly developed models; Model I (Insulated Rear Face) and Model II (Uninsulated Rear Face). The accuracy of the models simulating the heat conduction were evaluated using three different PFP on 10 mm thickness steel substrate exposing it to 116 kW/m2 constant heat flux. In this study, kaowool, furan microsphere and a commercial intumescent coating at different thicknesses are used as PFP. The results show that, although the three PFP thermal mechanism responses are different upon exposure to fire, the temperature-time profiles of each PFP show similar patterns. Simulation results demonstrate a reasonably good fit with experimental data for both models. This indicates that the developed models are capable to simulate temperature profile of steel substrate protected with different type of PFP. The third studies introduce nanoparticles as fire protection additives in the quest to improve the properties of intumescent coatings protection on steel substrate. The assessment tests relied on the exposure of the material to 116 kW/m2 heat flux by employing a direct flame from a propane burner. In this part of the work, a comparison of the additions of nanoclay, nanographene and multiwall carbon nanotubes, on their influence on intumescent coating behaviour, were studied. It is found that the addition of halloysite and graphene is able to maintain the substrate temperature below the steel failure temperature (450°C) after 2 hours of testing. Overall, this study has been able to give a better understanding of various aspect of PFP performance on aluminium and steel through the different trials conducted. Recently established multi-layered laminate have demonstrated positive potential to be further developed as PFP materials especially in application that required lightweight structure. The developed models enable the user to simulate various type of PFP on steel using small-scale propane burner testing to replicate large-scale testing where the results can be a guidance and assessment for further development of the PFP.