电阻率是胶凝材料固化的重要表征方法，为研究CaO掺入对赤泥电学性能的影响，对不同CaO掺量的赤泥进行了电阻率测试，利用低场核磁共振、X射线衍射和电镜扫描等手段，揭示样品电阻率变化的机理。结果表明：随着养护龄期的增加，试样的电阻率逐渐增大，不同龄期电阻率峰值对应的CaO掺量不同；随着CaO掺量和养护龄期的增加，试样的孔隙率增加、孔径增大，孔隙水连通性降低，导致其导电通路减少，电阻率升高，与此同时试样的孔隙水导电性却逐渐增强，说明孔隙水连通性对电阻率的影响高于孔隙水离子浓度；研究结果可为相关结构物的无损检测提供理论依据。

The resistivity is an important characterization method for the solidification of cementitious materials. To investigate the effect of CaO addition on the electrical properties of red mud, resistivity tests were conducted on red mud samples with different CaO contents. Low-field nuclear magnetic resonance, X-ray diffraction, and electron microscopy were used to reveal the mechanism of resistivity changes in the samples. The results show that the resistivity of the samples gradually increase with the curing age, and the peak resistivity corresponding to different ages have different CaO contents. With the increase of the CaO content and curing age, the porosity and pore size of the samples increase, the connectivity of pore water decrease, resulting in a decrease in the conductive pathways and an increase in resistivity. At the same time, the conductivity of pore water gradually increase, indicating that the impact of pore water connectivity on resistivity is higher than that of pore water ion concentration. The results can provide a theoretical basis for non-destructive testing of related structures.