Supplementary cementing materials (SCMs) have proven effective in minimizing alkali-silica reaction (ASR) development. In addition, crystalline admixtures (CAs) have been identified as potential solutions to counteract damage in concrete. However, limited data on this topic is available in the literature. This study investigates the impact of CA on concrete damage and is divided into two phases: 1) the effectiveness of CA in self-healing cracks and restoring the mechanical properties of mechanically damaged concrete; 2) it explores concrete mixtures incorporating a wide range of binder compositions (i.e., general use type cement, silica fume, fly ash, slag and Metakaolin) and chemical admixtures (i.e., commercially available CAs and modified versions) in conditions enabling ASR development. Both phases involve microscopic/mechanical analyses to assess the effects of CA on damage, and comparisons with concrete mixtures without CAs are made. The results reveal that CA enhanced the self-healing of cracks up to 82 % of cracks in cement paste (115 % higher values than concrete mixtures without CA) and restored 69 % of compressive strength. Furthermore, although CAs could change the damage mechanism of ASR, they did not “safely” mitigate it. However, combining SCMs and CAs effectively reduces ASR-induced expansion.

事实证明，辅助胶凝材料 (SCM) 可有效减少碱硅反应 (ASR) 的发生。此外，结晶外加剂（CA）已被认为是抵消混凝土损坏的潜在解决方案。然而，文献中关于该主题的数据有限。本研究探讨CA对混凝土损伤的影响，分为两个阶段：1）CA在自修复裂缝和恢复机械损伤混凝土力学性能方面的有效性；2) 它探索了在 ASR 开发条件下掺入各种粘合剂成分（即通用型水泥、硅灰、粉煤灰、矿渣和偏高岭土）和化学外加剂（即市售 CA 和改性版本）的混凝土混合物。这两个阶段都涉及微观/机械分析，以评估 CA 对损坏的影响，并与不含 CA 的混凝土混合物进行比较。结果表明，CA 使水泥浆中裂缝的自愈能力提高了 82%（比不含 CA 的混凝土混合物高出 115%），并恢复了 69% 的抗压强度。此外，尽管 CA 可以改变 ASR 的损害机制，但它们并没有“安全”地减轻它。然而，将 SCM 和 CA 结合起来可以有效地减少 ASR 引起的扩展。