当水化产物开始相互搭接时，试样致密性增大，离子和水在试样中的扩散受阻。

When the hydration products begin to overlap each other, the density of the sample increases and the diffusion of ions and water in the sample is hindered. As the nanoparticles are dispersed in the voids between the cement particles, the hydration products are able to fill the voids in the cement paste well, resulting in a reduction in porosity and the number of macropores [159].

When the hydration products begin to overlap each other, the compactness of the sample increases and the diffusion of ions and water in the sample is blocked. As the nanoparticles are dispersed in the voids between cement particles, the hydration products can well fill the voids in the cement slurry, resulting in the reduction of porosity and the number of macropores [159].

When hydration products begin to overlap each other, the compactness of the sample increases, and the diffusion of ions and water in the sample is blocked. Because nanoparticles are dispersed in the gaps between cement particles, hydration products can well fill the gaps in cement paste, resulting in the reduction of porosity and the number of macropores [159].