This paper studies the effect of various red mud proportions on the strength and microstructural changes in the ferrosialate geopolymer mortar. The optimum percentage of red mud (RM) has to be found with respect to the molarity of Sodium hydroxide (NaOH) to maintain the suitable alkalinity of the mixture for maximum strength gain. This percentage has been found to be between 20 and 30% RM proportions. From XRD micrographs, it has been found that the crystallinity percentage increased with the increase in red mud content. For oven-cured samples, SEM images showed that, till the red mud replacement reaches 20%, any increase in the red mud leads to denser microstructure and a decrease in intensity of unreactive particles. Beyond that, samples displayed a higher number of undissolved phases. Whereas, for ambientcuring specimens, this limit is found to be 30%. Synergy has to be found among the red mud content, curing type and curing temperature for optimum results. Ferrosialate geopolymer samples has shown 53.34% higher maximum compressive strength than sialate geopolymer samples. The oxide ratios of SiO₂/Al₂O₃ = 4.0 to 4.3, Na₂O/SiO₂ = 0.15 to 0.17 and Fe₂O₃/Al₂O₃ = 0.27 to 0.37 have found to be limits for favouring maximum strength gain.

中文翻译：

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赤泥配比对铁酸铝盐基聚合物砂浆强度和微观结构的影响

本文研究了不同比例的赤泥对铁硅酸盐岩聚合物砂浆强度和微观结构变化的影响。必须找到相对于氢氧化钠（NaOH）摩尔浓度最佳的赤泥（RM）百分比，以保持混合物的适当碱度，以最大程度地获得强度。已经发现该百分比在RM的20至30％之间。从XRD显微照片发现，结晶度百分比随赤泥含量的增加而增加。对于烘箱固化的样品，SEM图像显示，直到赤泥替代量达到20％为止，赤泥的任何增加都会导致致密的微观结构和未反应颗粒强度的降低。除此之外，样品还显示出更多的未溶解相。而对于环境固化样品，发现此限制为30％。为了获得最佳效果，必须在赤泥含量，固化类型和固化温度之间找到协同作用。亚铁酸盐地质聚合物样品的最大抗压强度比唾液酸地质聚合物样品高53.34％。SiO的氧化物比₂ / Al ₂ O ₃＝ 4.0至4.3，Na ₂ O / SiO ₂＝ 0.15至0.17和Fe ₂ O ₃ / Al ₂ O ₃＝ 0.27至0.37是有利于最大强度增加的极限。