Concrete technologists use different types of additives such as fly ash, slag, natural pozzolans and nanomaterials toenhance concrete performance and durability. However, a detailed explanation of the early-age hydration process and microstructural modification of concrete in the presence of nanomaterials remains to be presented and extensive research is required for strategic modification of cementitious systems. This study focused on the precise monitoring of early-age hydration with the incorporation of nanoalumina (nAl) in tricalcium silicate (C₃S) and Portland cement paste and mortar. The dosage of nAl was varied from 1 to 5% (by weight) in C₃S and from 0.1 to 1.0% in Portland cement, with a water/cement ratio of 0.4. The hydration studies showed that the nAl increased the cross-linkage in calcium silicate hydrate gel through substitution of aluminium by silicon, which was responsible for the enhancement of the modulus of elasticity (by 40%) with 1.0% nAl) after 7 days of hydration. In summary, the incorporation of nAl modified the concrete microstructure in the initial days of hydration, leading to higher concrete performance and longer service lives of concrete structures.

中文翻译：

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掺入纳米氧化铝的胶凝材料的早期水化研究

混凝土技术人员使用不同类型的添加剂，如粉煤灰、矿渣、天然火山灰和纳米材料来增强混凝土的性能和耐久性。然而，对纳米材料存在下混凝土的早期水化过程和微观结构改性的详细解释仍有待提出，并且需要对水泥体系的战略改性进行广泛的研究。本研究的重点是通过在硅酸三钙 (C ₃ S) 和波特兰水泥浆体和砂浆中掺入纳米氧化铝 (nAl) 来精确监测早期​​水化。 nAl的用量在C ₃ S中为1%至5%（重量），在波特兰水泥中为0.1%至1.0%，水/水泥比为0.4。水化研究表明，nAl 通过用硅取代铝来增加硅酸钙水合物凝胶中的交联，这导致水化 7 天后弹性模量提高（1.0% nAl 时提高 40%） 。总之，nAl的加入改变了混凝土在水化初期的微观结构，从而提高了混凝土的性能并延长了混凝土结构的使用寿命。