Durability is one of the key properties of the cement-based materials (CBMs) and is affected significantly by water migration in CBMs. Sorptivity S and capillarity coefficient k are two of the vital parameters to evaluate the water migration behavior of CBMs and are related closely to its microstructure. In this study, the low-field nuclear magnetic resonance (LF-NMR) was used to measure the pore size distribution and porosity of mortars. Additionally, according to the authors’ previous experimental results using the LF-NMR imaging and gravimetric method, the S and k were calculated, respectively. The results showed that the equivalent pore radius r_m of mortar, determined by the pore size distribution, increased with water to binder (w/b) ratio and sand to binder (s/b) ratio, and decreased with silica fume (SF) and super-absorbent polymer (SAP) content. However, the porosity of mortar increased with w/b ratio and SF content, decreased with s/b ratio, while first increased and then decreased with SAP content. Meanwhile, the S was improved with the increasing w/b ratio and SF content, deteriorated with the increase in s/b ratio, while first improved and deteriorated with SAP content. The trend of the k of mortar was similar to that of S. The analytical models for predicting S and k of mortars were proposed, which were based on their microstructure and considered the effects of tortuosity and roundness, and were successfully verified by the test results with the present investigation and the existing literatures. Besides, the relationship between S and k was given and the ratio k/S was approximately between 5.0 and 10.0.

耐久性是水泥基材料（CBM）的关键特性之一，并且受CBM中水迁移的影响很大。吸附度S和毛细系数k是评估煤层气水迁移行为的两个重要参数，并与其微结构密切相关。在这项研究中，低场核磁共振（LF-NMR）用于测量砂浆的孔径分布和孔隙率。此外，根据作者先前使用LF-NMR成像和重量分析法得出的实验结果，分别计算了S和k。结果表明，等效孔半径r _m砂浆的比重由孔径分布决定，随水与粘结剂（w / b）的比值和砂与粘结剂（s / b）的比值而增加，而随着硅粉（SF）和超吸收性聚合物（SAP）的含量而降低。但是，砂浆的孔隙度随w / b比和SF含量的增加而增加，随s / b比的降低而减小，而随SAP含量的增加先降低后降低。同时，随着w / b比和SF含量的增加，S有所提高，随着s / b比的增加，S逐渐降低，而首先随着SAP内容的改进和恶化。砂浆的k趋势与S相似。基于砂浆的微观结构并考虑了曲折度和圆度的影响，提出了砂浆的S和k预测分析模型，并通过测试结果进行了验证。与目前的调查和现有的文献。此外，给出了S和k之间的关系，并且比率k / S大约在5.0和10.0之间。