Supplementary cementitious materials (SCMs) are essential for enhancing both the performance and sustainability of modern cement systems. Among these, lithium slag (LS) has emerged as a promising candidate, though its impact on cement hydration remains insufficiently understood. As an aluminosilicate-based material, LS can synergistically interact with carbonate additives like limestone powder (LP), promoting the formation of carboaluminates. This synergy not only significantly reduces cement consumption but also markedly enhances the long-term performance of cementitious systems. However, the combined use of LS and LP as a SCM remains underexplored and warrants further investigation. Therefore, this study examines the hydration of LS-blended cement in the presence of LP. Additionally, the pore structure and aluminosilicate component in LS were analyzed to comprehensively evaluate its role as an SCM. The results indicate that aluminosilicates in LS exhibit high polymerization, which limits its reactivity. Nevertheless, LS's unique pore structure facilitates internal curing, which, along with pozzolanic reactions, enhances late-age strength and microstructure. Additionally, LS serves as an internal source of sulfate and aluminate, mitigating premature sulfate depletion caused by LP's hydration-accelerating effect and promoting the formation of carboaluminates. LS also enhances the polymerization of C-(A)-S-H by lowering the Ca/Si ratio and increasing the Al/Si ratio, achieving a mean chain length (MCL) of 3.590 at 28 d. The blended cement with 45 % combined SCM achieves MCL values and 90-day compressive strengths comparable to those of pure cement, demonstrating its potential for sustainable cement development.

中文翻译：

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锂渣和粗石灰石粉作为补充胶凝材料的协同效应：水化和微观结构


辅助胶凝材料 （SCM） 对于提高现代水泥系统的性能和可持续性至关重要。其中，锂渣 （LS） 已成为一个有前途的候选者，尽管其对水泥水化的影响仍未得到充分了解。作为一种基于铝硅酸盐的材料，LS 可以与石灰石粉 （LP） 等碳酸盐添加剂协同作用，促进碳铝酸盐的形成。这种协同作用不仅显著减少了水泥消耗，还显著提高了水泥系统的长期性能。然而，LS 和 LP 作为 SCM 的联合使用仍未得到充分探索，值得进一步研究。因此，本研究检查了 LS 混合水泥在 LP 存在下的水化。此外，还分析了 LS 中的孔隙结构和铝硅酸盐成分，以全面评价其作为 SCM 的作用。结果表明，LS 中的铝硅酸盐表现出高聚合度，这限制了其反应性。尽管如此，LS 独特的孔隙结构有助于内部固化，这与火山灰反应一起增强了后期强度和微观结构。此外，LS 作为硫酸盐和铝酸盐的内部来源，减轻 LP 的水合作用加速作用引起的硫酸盐过早消耗，并促进碳铝酸盐的形成。LS 还通过降低 Ca/Si 比和增加 Al/Si 比来增强 C-（A）-S-H 的聚合，在 28 d 时达到 3.590 的平均链长 （MCL）。含 45% 混合 SCM 的混合水泥达到 MCL 值和 90 天的抗压强度，可与纯水泥相媲美，展示了其可持续水泥发展的潜力。