| 张鹏,赵铁军,Wittmann F.H.,Lehmann E..基于中子成像的水泥基材料毛细吸水动力学研究[J].水利学报,2011,42(1): |
| 基于中子成像的水泥基材料毛细吸水动力学研究 |
| Water capillary suction dynamics of cement-based materials basedon neutron radiography method |
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| DOI： |
| 中文关键词: 水泥基材料 毛细吸水 中子成像 渗透深度 渗透系数 |
| 英文关键词: cement-based materials water capillary suction neutron radiography water penetration depth coefficient of water penetration |
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| 中文摘要: |
| 总结了国内外有关水泥基材料毛细吸水的动力学机理及其现有模型，应用中子成像技术对其毛细吸水过程进行了可视化再现，对水分侵入的空间分布规律进行了定量分析。结果表明，在毛细孔吸附力作用下，水分前锋不断向水泥基材料内部推进，在吸水初期速度较快，后趋于平缓直至稳定；水分侵入曲线在深度和含量上同时增
长，可以由线性+反S形模型来描述其空间分布特点，并与实测结果吻合良好；现有的 “时间开方” 及其修正模型对毛细吸水的后期预测不太合理，本文提出的渗透系数双曲线衰减模型更符合真实结果。 |
| 英文摘要: |
| Dynamic mechanism and current models for water capillary suction of cement-based materials are summarized. Neutron Radiography method was applied to visualize the time dependent process of capillary suction and quantitatively to analyze the spatial moisture distribution in the material during water capillary suction. Results indicate that water front moved deeper into the cement-based materials with higher speed at the beginning of contact followed by lower penetration speed until nearly equilibrium. Both in the direction of depth and quantity the moisture distribution curve increased，which variation can be described by linear-plus-reverse-sigmoid model. For the relationship between water penetration depth and contact time，current square-root-of-time model and its modified models are not perfect to predict capillary suction at the late age. A hyperbolic regression model for coefficient of water penetration is developed which is
well accord with the observed data. |
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