Abstract Tobermorite is the model for calcium aluminosilicate hydrate (C-(A-)S-H), the glue in concrete, and is also the binding phase in cement-based materials under geological conditions and in ancient Roman concrete. Correlating the mechanical properties of tobermorite with atomic structures substantially improves the understanding of C-(A-)S-H. We study this correlation for tobermorite with various Al contents using Raman, nuclear magnetic resonance spectroscopy, and high-pressure X-ray diffraction. Al incorporation shortens the cross-linked tobermorite chains, leading to more charge-balancing Ca and strong H-bonding, and enhancing the incompressibility of the basal-layer of Al-tobermorite. Non-cross-linked tobermorite exhibits high incompressibility of the basal layer but low incompressibility of the interlayer due to lack of cross-linking. The substitution of stronger Si O with Al O shows no negative influence on the mechanical properties of tobermorite. The results provide fundamental information on how atomic structure influences the intrinsic properties of C-(A-)S-H and have implications in validating computational methods and parameters.

中文翻译：

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交联和掺铝对雪硅钙石固有力学性能的影响

摘要 雪硅钙石是水合铝硅酸钙 (C-(A-)SH) 的模型，是混凝土中的胶水，也是地质条件下水泥基材料和古罗马混凝土中的结合相。将雪硅钙石的机械性能与原子结构相关联，大大提高了对 C-(A-)SH 的理解。我们使用拉曼、核磁共振光谱和高压 X 射线衍射研究了具有各种 Al 含量的雪硅钙石的这种相关性。Al 的掺入缩短了交联的雪硅钙石链，导致更多的电荷平衡 Ca 和强氢键，并提高了铝雪硅钙石基底层的不可压缩性。由于缺乏交联，非交联雪硅钙石表现出基底层的高不可压缩性但中间层的低不可压缩性。用 Al O 取代更强的 Si O 对雪硅钙石的机械性能没有负面影响。结果提供了关于原子结构如何影响 C-(A-)SH 的内在性质的基本信息，并对验证计算方法和参数具有影响。