Sodium-based fly ash geopolymers show great fire resistance potential and commercial advantage for structural applications. Hence, in current research, tailoring of sodium-based geopolymer mix design without changing the fly ash source has been studied. It was found that a wide variety of residual compressive strength ranging from significant reduction (∼80%) to maintaining significant enhancement (∼150%) after being exposed to 900°C was observed. The contributory mechanisms were discovered by investigating their chemical stability, pore structures, volume stability, and strength endurance prior to and after exposure to high-temperature using different microstructure characterization techniques including XRD, FTIR, MIP, dilatometry, and SEM. Crack formation due to moisture migration, pore shrinkage, and re-crystallization of nepheline adversely affected compressive strength. Matrix densification due to shrinkage of pore and stronger inter-particle bonding due to viscous sintering, favored compressive strength gain. This work discusses at length these competing mechanisms influencing the residual compressive strength.

钠基粉煤灰地质聚合物在结构应用方面显示出巨大的耐火潜力和商业优势。因此，在当前的研究中，已经研究了在不改变飞灰源的情况下定制钠基地质聚合物混合物设计的方法。发现在暴露于900℃后观察到各种各样的残余抗压强度，从显着降低（〜80％）到保持显着增强（〜150％）。通过使用不同的微观结构表征技术（包括XRD，FTIR，MIP，膨胀法和SEM）研究高温前后的化学稳定性，孔结构，体积稳定性和强度耐久性，从而发现了其作用机理。由于水分迁移，孔隙收缩，和霞石的重结晶会不利地影响抗压强度。由于孔的收缩而产生的基体致密化以及由于粘性烧结而产生的更强的颗粒间键合，有利于提高抗压强度。这项工作详细讨论了影响剩余抗压强度的这些竞争机制。