Improving fire performance of solid aluminium of composite cladding panels incorporating intumescent coatings

Abstract

The use of solid aluminium as non-combustible cladding panels and the outer layer of aluminium composite panels (ACP) has raised concerns about fire safety in high-rise buildings. Solid aluminium begins to melt at temperatures above approximately 660 °C, which can exacerbate fire hazards by transferring significant heat from the exposed side to the unexposed side. This research investigates the fire performance of solid aluminium by incorporating two different commercially available water-based intumescent coatings (Coating-A and Coating-B) under fire conditions with high temperatures around 1000 °C. The study evaluates 0.5 mm thick solid aluminium panels with and without coatings to determine their effectiveness in mitigating fire risks. Comprehensive analyses, including SEM, XRD, TGA and fire tests, were conducted to assess the microstructure, elemental composition, thermal degradation and fire behaviour. The findings reveal that while solid aluminium without intumescent coating presents significant fire risks when exposed to high temperatures, intumescent coatings can substantially improve the fire resistance of solid aluminium. When Coating-A is applied to both sides of the solid aluminium, it reduces melting with a resistance factor of 0.70. But it still allows some flame spread. In contrast, Coating-B provides exceptional fire protection with a resistance factor of 0.86, preventing melting and flame spread when applied to one side. Between Coating-A and Coating-B, Coating B provides better fire protection, allowing only 14 % heat transfer. However, the key issue is the potential hazard of airborne char particles generated from Coating-B. These results underscore the importance of selecting effective intumescent coatings to enhance fire safety in solid aluminium cladding systems.