深圳大学学报理工版

为研究水泥基材料内的孔结构,基于Lucas-Washburn方程,提出考虑分形维数的毛细孔分布反演模型.应用X射线计算机断层扫描技术无损表征水泥基材料的毛细吸收过程,通过分布曲线推断出样品的孔径分布,通过劈开试验及滴定试验验证了该技术的可行性.将该模型应用于粉煤灰质量分数为10%的水泥基复合材料中,结果表明,毛细管孔径越大,毛细管内水上升得越快,在毛细管吸水的早期阶段,毛细管内水上升的高度较大.由模型推导出累积孔径分布,将所得结果与压汞法测得的累积孔体积进行比较,相关度为0.942 6,证明了反演模型的准确性.

In order to study the pore structure of cementitious materials, an inverse model of the capillary distribution considering fractal dimension is proposed based on the Lucas-Washburn equation. X-ray computed tomography(XCT)is used to characterize the capillary absorption process non-destructively. The pore size distribution is inferred from the water content distribution, and the feasibility of the technique is verified by the split test and titration test. The model is applied to the cementitious materials with 10% fly ash. The results show that the larger the capillary pore diameter, the faster the water in the capillary rises, and in the early stage of capillary water absorption, the higher the water in capillary rises. The cumulative pore size distribution is derived from the model, and the correlation between the results and the cumulative pore volume measured by the mercury intrusion porosimetry is 0.942 6, which proves the accuracy of the inverse model.

引言
1 试验
2 反演模型的推导
3 结果与讨论
4 结论

表1 水泥和粉煤灰的化学成分<br/>Table 1 Chemical compositions of cement and fly ash %

表1 水泥和粉煤灰的化学成分
Table 1 Chemical compositions of cement and fly ash %

图1 吸水过程的X射线断层成像<br/>Fig.1 Radial sectional XCT images for visualizing the entire water absorption process

图1 吸水过程的X射线断层成像
Fig.1 Radial sectional XCT images for visualizing the entire water absorption process

图2 样品的平均CT值曲线<br/>Fig.2 The average CT number profiles

图2 样品的平均CT值曲线
Fig.2 The average CT number profiles

图3 吸水质量与包络面积的关系<br/>Fig.3 Correlation between the weight of the absorbed water and the enveloped area

图3 吸水质量与包络面积的关系
Fig.3 Correlation between the weight of the absorbed water and the enveloped area

图4 校正后的水分分布<br/>Fig.4 Water content profiles after calibration

图4 校正后的水分分布
Fig.4 Water content profiles after calibration

图5 XCT试验与劈开试验吸水高度对比图<br/>Fig.5 Comparison of the water absorption heights for the XCT test and the split test

图5 XCT试验与劈开试验吸水高度对比图
Fig.5 Comparison of the water absorption heights for the XCT test and the split test

图6 XCT试验与滴定试验碘离子质量对比<br/>Fig.6 Iodide content for every 2 mm of height after 240 min of absorption, measured by the XCT test and the titration test

图6 XCT试验与滴定试验碘离子质量对比
Fig.6 Iodide content for every 2 mm of height after 240 min of absorption, measured by the XCT test and the titration test

图7 吸水高度与吸收时间的拟合<br/>Fig.7 Fitting curve of absorption height versus time

图7 吸水高度与吸收时间的拟合
Fig.7 Fitting curve of absorption height versus time

图8 反演模型与压汞试验结果的对比<br/>Fig.8 The comparison of the result derived from the inverse model with that of mercury intrusion porosimetry test

图8 反演模型与压汞试验结果的对比
Fig.8 The comparison of the result derived from the inverse model with that of mercury intrusion porosimetry test

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备注

引言

1 试验

2 反演模型的推导

3 结果与讨论

4 结论

期刊信息

备注

引言

1 试 验

2 反演模型的推导

3 结果与讨论

4 结 论

期刊信息

1 试验

4 结论