To understand the microstructural changes in the hardened cement paste during the drying, hardened white Portland cement pastes were D-dried or dried under 11, 33, 40, and 75% relative humidity, and then, pastes were impregnated with 2-propanol or water under vacuum. Measurement of 1H NMR relaxometry was employed for the pastes before and after impregnation, and the full-scale microstructural changes of the hardened cement paste after drying were successfully visualized. It was observed that the volume of the coarse pores outside the agglomeration of calcium-silicate-hydrate (C-S-H) increased, and the volume of the C-S-H interlayer spaces and gel pores decreased as the drying relative humidity decreased. Thus, it was evidenced that interlayer space is decreasing during drying. It was also confirmed that 2-propanol can enter some of the interlayer space of C-S-H after harsh drying.

中文翻译：

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通过水和 2-丙醇 1H NMR 弛豫法全面观察硬化水泥浆体中干燥诱导的微观结构变化


为了解硬化水泥浆在干燥过程中的微观结构变化，将硬化白色硅酸盐水泥浆料在 11、33、40 和 75% 相对湿度下进行 D 干燥或干燥，然后在真空下用 2-丙醇或水浸渍浆料。对浸渍前后的浆料采用 1H NMR 弛豫法测量，成功地可视化了干燥后硬化水泥浆体的全面微观结构变化。结果表明，随着干燥相对湿度的降低，钙-硅酸盐-水合物 （CS-H） 团聚外的粗孔体积增加，C-S-H 层间空间和凝胶孔的体积减小。因此，有证据表明在干燥过程中层间空间正在减小。还证实了 2-丙醇在剧烈干燥后可以进入 C-S-H 的部分层间空间。