粉煤灰复合水泥基材料的孔结构反演模型分析

Inverse model of capillary pore distribution of fly ash mixed cement materials

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0.9426,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 0.9426,which proves the accuracy of the inverse model.