The effect of high temperature on the mechanical, durability, and microstructural properties of mortar containing alum sludge ash (ASA) was investigated in this paper. The ASA was derived from grinding and calcinating alum sludge, a typical by-product of the drinking water treatment processes. Four different mortar mixtures with ASA content at weight percentages of 0%, 10%, 20%, and 30% (as cement replacement) were exposed to high temperatures of 300 °C, 550 °C, and 800 °C, respectively. The experimental results showed that mortar samples containing up to 20% of cement replaced with ASA exhibited superior high-temperature resistance to the reference ones (without ASA), especially after exposure to 800 °C. The thermal analysis determined the portlandite consumption because of ASA pozzolanic reaction, and the x-ray diffraction pattern showed that the ASA reaction might contribute to the formation of aluminum-bearing phases with excellent refractoriness in the binder matrix. In addition, crack examination conducted by backscattered electron images evidenced that the ASA addition mitigated the binder paste degradation.

本文研究了高温对含铝污泥灰 (ASA) 砂浆的力学、耐久性和微观结构性能的影响。ASA 来源于研磨和煅烧明矾污泥，这是饮用水处理过程的典型副产品。ASA 含量分别为 0%、10%、20% 和 30%（作为水泥替代品）的四种不同砂浆混合物分别暴露于 300°C、550°C 和 800°C 的高温下。实验结果表明，含有高达 20% 的水泥用 ASA 代替的砂浆样品表现出优于参考样品（不含 ASA）的耐高温性，尤其是在暴露于 800°C 后。由于 ASA 火山灰反应，热分析确定了硅酸盐消耗量，X 射线衍射图表明 ASA 反应可能有助于在粘合剂基质中形成具有优异耐火度的含铝相。此外，通过背散射电子图像进行的裂纹检查证明添加 ASA 减轻了粘合剂糊的降解。