Slag, an important supplementary cementitious material, is widely utilized for producing sustainable cement-based materials. In this paper, to study the effect of hydration stage and composition on the microstructure of cement-slag powder composites, the hydrated tricalcium silicate (C₃S) curing at 20 °C at 28-day and 90-day with slag dosage from 0% to 45% were investigated by ²⁹Si and ²⁷Al NMR spectrum and molecular dynamics. Silicate connectivity from ²⁹Si NMR test showed that with increasing slag substitution content, the mean chain length (MCL) of the C₃S-slag hydrated paste at 28-day increased from 2.99 to 4.02 and the AlO₄/SiO₄ ratio rose from 0 to 0.043. Aluminate coordinates of ²⁷Al NMR analysis revealed that the incorporation of slag could contribute to transformation from ettringite to Aft and formation of Al [4] in the C-A-S-H gel. Furthermore, reactive force field molecular dynamics was utilized to study the structural, reactivity and mechanical properties of C-A-S-H gel in hydrated composite. The AlO₄ species in the C-A-S-H gel played an essential role in healing the defective silicate chains and transforming dimmer-rich silicate chains at low slag powder content to a long aluminate-silicate skeleton with high slag powder content. The structural evolution was attributed to the polymerization reaction between aluminate species and non-bridging silicate tetrahedron, with neighboring water molecule dissociations. In respect of dynamical properties, the aluminate-silicate structure exhibited good stability due to high Al–O–Si connection characterized by time correlated function. Uniaxial tensile modeling revealed that C-A-S-H gel with long aluminate-silicate chains exhibits good loading resistance and the cohesive strength of C-A-S-H gel is improved to a great extent due to the incorporation of slag powder. Hopefully, this study may provide molecular insights for design of sustainable and durable cement-slag powder composites.

炉渣是一种重要的辅助胶结材料，被广泛用于生产可持续的水泥基材料。为了研究水合阶段和组成对水泥-矿渣粉复合材料微观结构的影响，水化硅酸三钙（C ₃ S）在20°C下分别于28天和90天固化，炉渣用量为0通过²⁹ Si和²⁷ Al NMR光谱和分子动力学研究了1％至45％。²⁹ Si NMR测试的硅酸盐连通性表明，随着炉渣替代含量的增加，C ₃ S炉渣水合糊在28天时的平均链长（MCL）从2.99增加到4.02，而AlO ₄ / SiO ₄比率从0上升到0.043。铝酸盐的²⁷ Al NMR分析坐标表明，炉渣的掺入可能有助于钙矾石向Aft的转变以及在CASH凝胶中形成Al [4]。此外，利用反作用力场分子动力学研究了水合复合物中CASH凝胶的结构，反应性和机械性能。AlO ₄CASH凝胶中的各种物质在修复有缺陷的硅酸盐链并将低渣粉含量的富二聚体硅酸盐链转变为长渣粉含量高的长铝酸盐-硅酸盐骨架方面起着至关重要的作用。结构的演变归因于铝酸盐物质与非桥连的硅酸盐四面体之间的聚合反应，以及邻近的水分子解离。在动力学性能方面，铝硅酸盐结构表现出良好的稳定性，这归因于具有时间相关功能的高Al-O-Si连接。单轴拉伸模型表明，具有长铝酸盐-硅酸盐链的CASH凝胶表现出良好的抗负载性，并且由于掺入了矿渣粉，CASH凝胶的内聚强度得到了很大的提高。希望，