不同含气量水泥砂浆孔体积分形维数研究

发布时间：2018-04-02 22:19

本文选题：桥梁工程　切入点：孔结构　出处：《公路交通科技》2016年06期

【摘要】：采用压汞仪、气孔结构分析仪测定了不同含气量水泥砂浆的孔结构参数,通过热力学关系的分形模型计算得到了水泥砂浆不同尺度孔结构分形维数,并分析了水泥砂浆不同尺度孔结构孔体积分形维数与孔隙率、平均孔径、孔比表面积、孔间距系数、孔总体积关系。结果表明:基于热力学关系的分形模型计算得到的不同尺度孔结构分形维数呈现多重性,能够很好地表征水泥砂浆孔结构的复杂程度;含气量的增加,使得102nm以上孔径范围的分形维数呈增大的趋势,而102nm以下孔径范围的分形维数呈减小趋势;龄期的增加,103~104nm孔径范围的分形维数呈减小趋势,其他孔径范围内分形维数呈增大趋势;各孔结构参数中,103~104nm及102~103nm孔径范围内孔体积分形维数与孔隙率、平均孔径、总孔体积具有良好的相关关系,与孔比表面积相关性极差。考虑到102~103nm范围孔径孔在总孔中所占比例较高,因而可将其作为统一的分形维数来表征孔结构参数的变化。
[Abstract]:The pore structure parameters of cement mortar with different air content were measured by mercury injection instrument and pore structure analyzer. The fractal dimension of pore structure of cement mortar at different scales was calculated by fractal model of thermodynamic relationship.The relationship between the fractal dimension of pore volume and porosity, average pore size, pore specific surface area, pore spacing coefficient and total pore volume of cement mortar is analyzed.The results show that the fractal dimension of different size pore structures is multifold, which can well characterize the complexity of the pore structure of cement mortar and the increase of gas content.The fractal dimension of the aperture range above 102nm tends to increase, while the fractal dimension of the aperture range below 102nm tends to decrease, and the fractal dimension of the pore size range of 103n 104nm decreases with the increase of age.The fractal dimension of pore volume and porosity, average pore size and total pore volume in various pore structure parameters in the range of 103nm-104nm and 102~103nm pore size have a good correlation, and the correlation with pore specific surface area is very poor.Considering the high proportion of pore size in 102~103nm range, it can be used as a unified fractal dimension to characterize the variation of pore structure parameters.
【作者单位】：兰州交通大学土木工程学院;兰州工业学院土木工程学院;
【基金】：国家自然科学基金项目(51268032) 长江学者和创新团队发展计划滚动支持项目(IRT_15R29)
【分类号】：TQ177.62

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