基于交流阻抗谱法检测水泥砂浆裂缝试验研究

以预设不同尺度裂缝的水泥砂浆块体和无裂缝水泥砂浆块体等三组试件为试验研究对象，基于交流阻抗谱测试技术，采用变化频率的正弦波脉冲作为激励信号，测试各试件电压信号峰峰值和相位差，计算相应的阻抗幅模量和进行相关数据分析。结果表明，同类试件的阻抗谱具有很好的相似性和一致性，阻抗谱可作为表征水泥砂浆材料性能的本征参数；有无预设裂缝水泥砂浆试件的阻抗幅模量差异明显，基于阻抗谱检测水泥砂浆内部裂缝可行；阻抗特性与裂缝几何尺度之间存在量化关系；水泥砂浆试件呈现电容性。

Experimental Study on Crack Detection to Cement Mortar Based on AC Impedance Spectroscopy

Nine cement mortar specimens with or without crack were designed to be tested for the peak-to-peak values of voltage signal, as well as phase difference, based on the AC impedance spectroscopy testing technology. Sine wave pulses with different frequency were used as excitation signal during testing. The dimension of crack designed in the cement mortar varied to investigate crack dimension effect on electrochemical impedance properties of the specimens. The impedance amplitude for each sample was figured out, and the fitted curve equation for the relationship between impedance modulus and frequency of each group was built with the least square method. Results show that the impedance spectrums of specimens with the same crack configuration are similar to each other, so impedance spectrum is the intrinsic property of cement mortar; The impedance amplitude for the specimens with or without crack is quite different from one to another; A mathematics model was proposed to present the relationship between impedance characteristics and crack geometry scale.