Abstract A modified non-contact electrical resistivity measurement is proposed to determine porosity and pore network connectivity of cement-based materials. The porosity of mortar with different water-to-cement ratios was tested by mercury intrusion porosimetry (MIP) and the tortuosity was calculated from pore entrapment volume fraction. The relationship between pore structure and resistivity was studied using the three most commonly used theories. It was observed that the multi-phase phenomenological model can indicate the effect of porosity and pore connectivity on the resistivity of cement-based materials. The parameter m in Archie's Law as an index of pore connectivity can be expressed as a variable that varies with the tortuosity. The parameters in the GEM model are closely related to the nature of the material: the parameter M should be related to the composition of the material and the degree of hydration of the cement, and the parameter t is a variable that varies with the pore connectivity. Based on these theories, equations are derived to correlate the porosity and pore network connectivity to the formation factor of cement based materials. The developed approach thus has a potential to be used as a simple and effective tool for pore structure investigation of cement based materials.

中文翻译：

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通过改进的非接触电阻率测量确定水泥基材料的孔隙率和孔隙网络连通性：实验和理论

摘要 提出了一种改进的非接触电阻率测量方法来确定水泥基材料的孔隙率和孔隙网络连通性。通过压汞孔隙率法（MIP）测试不同水灰比的砂浆的孔隙率，并根据孔隙截留体积分数计算曲率。使用三种最常用的理论研究了孔隙结构和电阻率之间的关系。据观察，多相现象学模型可以表明孔隙度和孔隙连通性对水泥基材料电阻率的影响。Archie 定律中作为孔隙连通性指标的参数 m 可以表示为随曲率变化的变量。GEM模型中的参数与材料的性质密切相关：参数 M 应与材料的成分和水泥的水化程度有关，参数 t 是随孔隙连通性变化的变量。基于这些理论，推导出了将孔隙度和孔隙网络连通性与水泥基材料的形成因子相关联的方程。因此，所开发的方法有可能用作一种简单有效的水泥基材料孔隙结构研究工具。