Influences of cross-linking and Al incorporation on the intrinsic mechanical properties of tobermorite
Influences of cross-linking and Al incorporation on the intrinsic mechanical properties of tobermorite
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DOI：
10.1016/j.cemconres.2020.106170
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发表时间：
2020-10-01
影响因子：
11.4
通讯作者：
Monteiro, Paulo J. M.
中科院分区：
文献类型：
--
作者：
Li, Jiaqi;Zhang, Wenxin;Monteiro, Paulo J. M.
托贝莫来石是混凝土中的胶凝剂水合铝酸钙（C-（A-）S-H）的模型，也是地质条件下水泥基材料和古罗马混凝土中的粘结相。将雪硅钙石的力学性能与原子结构联系起来，大大提高了对C-（A-）S-H的理解。我们研究了这种相关性雪硅钙石与各种铝含量使用拉曼，核磁共振光谱，高压X射线衍射。铝的掺入缩短了雪硅钙石的交联链，导致更多的电荷平衡钙和强氢键，并提高了铝雪硅钙石的基底层的不可压缩性。非交联雪硅钙石由于缺乏交联而表现出基底层的高不可压缩性，但夹层的低不可压缩性。Al-O取代较强的Si-O对雪硅钙石的力学性能没有负面影响。这些结果提供了关于原子结构如何影响C-（A-）S-H的内在性质的基本信息，并在验证计算方法和参数方面具有意义。
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.