Heat and fire resistance of geopolymer concrete

Geopolymer concrete, made from aluminosilicate materials like fly ash and an alkaline solution, is an eco-friendlier alternative to Portland cement. While its use is growing, more research is needed to explore its commercial applications, particularly for high-temperature resistance. The effects of high-temperature exposure on geopolymer concrete were evaluated and compared with those of normal concrete. Geopolymer concrete specimens were heat cured at 115°C for 24 hours, followed by storage at room temperature until 28 days of age. In contrast, normal concrete specimens were cured in water at room temperature. Both concrete types were then heated in an iron furnace at 400°C-800°C for 2 hours, after which they were cooled and tested. A visual inspection assessed the concrete for spalling, cracking, and discoloration, while tests measured mass loss and residual compressive strength. Results indicated that both geopolymer and traditional concrete lost compressive strength after burning; however, at 800°C, geopolymer concrete maintained a 10.09% higher residual strength. Geopolymer concrete also showed less weight loss due to lower water content and exhibited no spalling. In summary, geopolymer concrete resists high temperatures better than normal concrete.