Thermal degradation, fire performance and combustibility of ceramified composites incorporating waste glass for sustainable building applications

The pursuit of sustainable and fire-safe construction materials has driven interest in repurposing waste glass particles as fillers in polymer composites. This study evaluates the thermal stability, fire reaction behaviour, combustibility and flexural properties of glass particulate-reinforced epoxy composites incorporating fire retardants. The thermal stability of the glass/epoxy composites was evaluated under oxidative and inert conditions using thermogravimetric analysis (TGA). Fire reaction properties and flammability characteristics of the glass/epoxy composites were evaluated using the cone calorimetry and the AS1530.1 combustibility tests. Focus was placed on the influence of ceramification, a high temperature polymer matrix transformation process, on the flexural properties, thermal stability and fire reaction properties of the composites. X-ray computed tomography (CT) and scanning electron microscopy (SEM) were employed to examine microstructural evolution before and after ceramification. These analyses enabled the correlation of microstructural changes with variations in flexural properties. Ceramified composites demonstrated enhanced fire performance, including reductions in peak heat release rates and smoke production. However, these improvements were achieved at the cost of flexural properties, attributed to ceramification-induced void formation and glass/epoxy interfacial degradation. • Development of sustainable composite materials using waste glass for fire-prone construction applications. • Superior thermal stability and fire resistance of ceramified glass/epoxy composites compared to non-ceramified counterparts. • Highest residual char yield observed in EP-6 (6 wt.% epoxy polymer resin) composite due to its higher glass particle content. • Ceramified composites passed the AS1530.1 combustibility standard, confirming their suitability for fire-prone environments. • Flexural properties increased with epoxy content, with EP-12 (12 wt.% epoxy polymer resin) demonstrating significantly higher flexural strength and modulus than EP-6. In ceramified composites, flexural strength and modulus increased by 309% and 129%, respectively, as the epoxy content increased from 6 wt.% in EP-6 to 12 wt.% in EP-12. • Ceramified composites exhibited reduced flexural properties compared to the non-ceramified composites due to void formation, glass/epoxy interfacial debonding, and thermal degradation from the ceramification process.