水工混凝土高低阻异常体的识别分辨率试验研究

水工混凝土内部缺陷的电阻率表现为局部高低阻异常，探究不同电极排列对高低阻区的识别分辨率是高密度电法无损检测的关键。通过高低阻相似材料模拟水工混凝土内部异常体，开展α、β、γ三种电极排列下不同高低阻异常体试件的识别分辨率试验研究。试验结果表明：高阻异常体试件中分辨率为α > β > γ，低阻异常体试件中分辨率为γ > β > α，高-低阻异常体试件中分辨率为β > α > γ，即探测孔洞、空腔为主的水工混凝土缺陷可优先选择α排列，探测渗漏区为主的水工混凝土缺陷可优先选择γ排列。若水工混凝土内部缺陷同时包含孔洞、空腔和渗漏区则可选择兼容性较好的β排列。以上研究成果可为高密度电法在水工混凝土无损检测中的应用提供技术支撑。

Experimental study on identification resolution of resistivity abnormal zones in hydraulic concrete

The resistivity of hydraulic concrete with internal defects shows local high and low resistance anomalies. It is the key of high-density electrical nondestructive tests to enhance the identification resolution of high and low resistance zones through different electrode arrangements. An experimental study is conducted using three electrode arrangements of α, β and γ to explore the identification resolution of resistance abnormal bodies, by simulating the abnormal bodies in the concrete with materials of similar high and low resistance. The test results show that the abnormal body specimens from high to low resolution are ranked as α > β > γ for high resistance, γ > β > α for low resistance, and β > α > γ for high-low resistance. This means that the arrangement α is better for the concrete defects of holes and cavities, γ better for those of leakage, and β for those of holes, cavities, leakage, etc. The results help promote the application of high-density electrical methods in the nondestructive tests of hydraulic concrete.