Abstract The link between anomalous water sorption and dynamic porosity in cement pastes is explored using spatially resolved GARField 1H nuclear magnetic resonance (NMR) relaxation analysis. A model is developed in which the effective capillary diffusion coefficient is dependent on the instantaneous pore size distribution. This and earlier data show changes in pore size distribution resultant from changes in saturation that do not occur instantaneously with changes in degree of saturation. Therefore, it is assumed that the pore size distribution is always relaxing exponentially towards a (saturation dependent) equilibrium. It follows that the diffusivity is sample history (i.e. time) dependent as well as saturation dependent. This is sufficient to explain anomalies in rapid capillary water sorption. The same concepts are applied to slow drying. In this case, porosity changes occur on a timescale much shorter than drying so the system is always in dynamic equilibrium and anomalies are therefore not seen.

中文翻译：

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水泥浆中的吸附、异常水传输和动态孔隙度：空间局部 1H NMR 弛豫研究和建议的机制

摘要 使用空间分辨 GARField 1H 核磁共振 (NMR) 弛豫分析探索了水泥浆中异常吸水与动态孔隙率之间的联系。开发了一个模型，其中有效毛细管扩散系数取决于瞬时孔径分布。该数据和之前的数据显示了由饱和度变化引起的孔径分布变化，这些变化不会随着饱和度的变化立即发生。因此，假设孔径分布总是朝着（饱和度相关的）平衡呈指数松弛。因此，扩散系数与样本历史（即时间）有关，也与饱和度有关。这足以解释快速毛细管吸水的异常现象。相同的概念适用于慢干。