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Abstract：
The degradation of concrete and reinforced concrete structures is a significant technical and economic challenge, requiring continuous repair and rehabilitation throughout their service life. Geopolymers (GPs), known for their high mechanical strength, low shrinkage, and durability, are being increasingly considered as alternatives to traditional repair materials. However, there is currently a lack of understanding regarding the interface bond properties between new geopolymer layers and old concrete substrates. In this paper, using advanced computational techniques, including quantum mechanical calculations and stochastic modeling, we explored the adsorption behavior and interaction mechanism of aluminosilicate oligomers with different Si/Al ratios forming the geopolymer gel structure and calcium silicate hydrate as the substrate at the interface bond region. We analyzed the electron density distributions of the highest occupied and lowest unoccupied molecular orbitals, examined the reactivity indices based on electron density functional theory, performed Mulliken charge population analysis, and evaluated global reactivity descriptors for the considered oligomers. The results elucidate the mechanisms of local and global reactivity of the oligomers, the equilibrium low-energy configurations of the oligomer structures adsorbed on the surface of C-(A)-S-H(I) (100), and their adsorption energies. These findings contribute to a better understanding of the adhesion properties of geopolymers and their potential as effective repair materials.
摘要：
混凝土和钢筋混凝土结构的退化是一项重大的技术和经济挑战，需要在整个使用寿命内持续维修和康复。地质聚合物（GP），以其高机械强度而闻名，低收缩率,和耐用性，越来越多地被认为是传统修复材料的替代品。然而,目前缺乏对新地质聚合物层和旧混凝土基材之间的界面粘结性能的理解。在本文中,使用先进的计算技术，包括量子力学计算和随机建模，我们探索了具有不同Si/Al比的硅铝酸盐低聚物的吸附行为和相互作用机理，形成了地聚合物凝胶结构，并在界面键区以水合硅酸钙为基底。我们分析了最高占据和最低未占据分子轨道的电子密度分布，检查了基于电子密度泛函理论的反应性指数，进行了Mulliken电荷群体分析，并评估了所考虑的低聚物的全局反应性描述符。结果阐明了低聚物的局部和整体反应性的机制，吸附在C-（A）-S-H（I）（100）表面的低聚物结构的平衡低能构型，和它们的吸附能。这些发现有助于更好地了解地质聚合物的粘附特性及其作为有效修复材料的潜力。
