Alkali-activated Fe-rich non-ferrous metallurgical slags (AA-NFMS) emerge as a novel, sustainable cementitious binder, but durability performance is one of the crucial parameters to assess their success. This paper investigates the degradation mechanisms of AA-NFMS in 4 wt% acetic acid (AcH) solutions, commonly found in agricultural industries. The results indicated that upon AcH exposure, the amorphous structure of AA-NFMS is changed. This process is accompanied by the release of crucial elements, including Ca, Fe, and a smaller amount of Al and Si, resulting in the formation of a more polymerized network. Fe could precipitate near the formed cracks. EPMA and micro-CT revealed the important role of crack formation and the initial permeability of AA-NFMS on the degradation process. Additionally, strength change does not correlate with mass change but is closely related to the permeability. Notably, AA-NFMS with 10 wt% CaO demonstrates the highest strength after AcH exposure.

中文翻译：

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碱活化富铁渣在醋酸中的降解


碱活化富铁冶金渣 （AA-NFMS） 是一种新型的、可持续的水泥基粘结剂，但耐久性能是评估其成功的关键参数之一。本文研究了 AA-NFMS 在农业工业中常见的 4 wt% 乙酸 （AcH） 溶液中的降解机制。结果表明，在 AcH 暴露时，AA-NFMS 的非晶结构发生了变化。这个过程伴随着关键元素的释放，包括 Ca、Fe 和少量的 Al 和 Si，从而形成聚合程度更高的网络。Fe 可以在形成的裂纹附近沉淀。EPMA 和 micro-CT 揭示了裂纹形成和 AA-NFMS 的初始渗透率对降解过程的重要作用。此外，强度变化与质量变化无关，但与磁导率密切相关。值得注意的是，具有 10 wt% CaO 的 AA-NFMS 在 AcH 暴露后表现出最高的强度。