不同干密度下重塑南阳膨胀土的电化学阻抗谱特性研究

采用电化学工作站，对不同干密度下南阳重塑膨胀土进行电化学阻抗谱检测，借助等效电路参数探究干密度与重塑南阳膨胀土电化学阻抗谱之间的规律。结果表明:5种干密度的重塑膨胀土的电化学阻抗谱均呈现非Randles模型。随着干密度的增加，和试样孔隙比有关的溶液电阻Rs和电荷转移电阻Rt单调减小，双电层电容CPE-T逐渐增加。土体内部孔隙水的状态可以通过溶液电阻Rs衡量；土体内部的孔隙连通性可以通过电荷转移电阻Rt衡量；土体的孔隙结构和溶液浓度对双电层电容CPE-T有影响。电化学方法适用于表征膨胀土的压实特性，丰富了电化学阻抗谱的研究范围。

EIS Characteristics Research on Nanyang Remolded Expansive Soil in Different Dry Densities

Herein electrochemical workstation was used to check the electrochemical impedance spectroscopy (EIS) of Nanyang remolded expansive soil in different dry densities and, in virtue of the equivalent circuit parameters, the law between the dry density and the EIS thereof was explored. The result shows that all of the EIS of remolded expansive soil in 5 dry densities present un-Randles model; as the dry density increases, the solution resistance Rs and the charge transfer resistance Rt, which relate to the porosity ratio of specimen, decrease monotonically, and the electric double layer capacitor CPE-T increases gradually; the condition of pore water inside the soil mass can be measured by the solution resistance Rs, and the pore connectivity therein by the charge transfer resistance Rt; both the pore structure of the soil mass and the solution concentration have certain effect on the electric double layer capacitor CPE-T. Electrochemical method is applicable to represent the compaction characteristics of expansive soil, which enriches the study scope of EIS.