## 2 Computational Simulation Details  
### Molecular Model  
The approach suggested by [PERSON] et al. [14] to establish the amorphous C-S-H structure served as a foundation for the current study; the starting structure for the amorphous C-S-H structure was a supercell from [PERSON]'s proposed monoclinic Tobermorite-11 A layered structure. The specific method was as follows. (1) The monoclinic structure of the supercell was transformed into a cubic structure, while the atomic cartesian positions and model dimensions were kept consistent. After this, the C-S-H structure dimensions in x, y, and z were 22.32 A, 22.17 A, and 22.77 A, respectively, and the angles \(\alpha\), \(\beta\), and \(\gamma\) were all 90\({}^{\circ}\). (2) To match the actual distribution characteristics of the C-S-H silicates chain, as observed in nuclear magnetic resonance (NMR) experiments, some SiO\({}_{2}\) groups were randomly removed from the C-S-H structure [14]. (3) The ordered distribution water molecules in this structure were removed, and then water molecules were arbitrarily introduced into the C-S-H structure interlayer region, to reach water saturation using the grand canonical Monte Carlo absorption technique. (4) The saturated models were then relaxed by 1000 ps under the isothermal-isobaric (NPT) ensemble, nearly to equilibrium. Based on the above method, the obtained C-S-H's molecular formula was (CaO)\({}_{1.67}\)(SiO\({}_{2}\))\(\cdot\)(H\({}_{2}\)O)\({}_{1.68}\). Meanwhile, the density of the final structure (2.45 g/cm\({}^{3}\)), the structure of the silicon chain Q\({}_{\rm n}\) distribution (Q\({}_{0}\) = 11.63%, Q\({}_{1}\) = 67.44%, and Q\({}_{2}\) = 20.93%), and the average chain length (MCL = 2.62), as shown in Figure 1a, were in agreement with the previous simulations [14] and experimental results [15].  
In this research, the silica crystal was utilized to simulate the aggregate, where the sizes of the lattice were x = y = 4.913 A, z = 5.4052 A, and the angles of the lattice were \(\alpha\) = \(\beta\) = 90\({}^{\circ}\), \(\gamma\) = 120\({}^{\circ}\). To construct the ideal C-S-H/SiO\({}_{2}\) interface, additional processing was required for the established C-S-H structure and the selected SiO\({}_{2}\) crystal. Firstly, the established C-S-H structure was cut along the [001] direction, so that the z-direction surface was exposed, and the resulting model had the final dimensions x = 43.73 A, y = 44.25 A, and z = 47 A. Secondly, the SiO\({}_{2}\) model was also cut along the [001] direction, and supercells were generated in the x- and y-axis directions, until it matched the dimensions of the C-S-H cross-section. Figure 1b displays the established SiO\({}_{2}\) model. At last, the C-S-H/SiO\({}_{2}\) interface model was completed, after the SiO\({}_{2}\) crystal model was placed on the C-S-H interface.  
To examine the interfacial water content impact mechanism on the bonding performance of the C-S-H/SiO\({}_{2}\) system, the models that had varying water-layer thicknesses (0 A, 1 A, 3 A, and 5 A) were selected as the study subjects. This is shown in Figure 1d-g, where the preparation of water layers was achieved by the absorption of water molecules within a box of the rated thickness (0 A, 1 A, 3 A, and 5 A) and its density was established at 1 g/cm\({}^{3}\), as seen in Figure 1c.