A method based on AC impedance characteristics of concrete was put forward for crack detection and damage assessment.Using the steel bars as electrodes,three groups of concrete specimens with different strengths were designed for splitting tensile testing,and both the impedance amplitude (z) and phase angle (φ) were measured by MT4090 LCR measuring instrument during testing.The results showed that there are significant differences in crack evolutionary among the three phases of splitting tensile process,meanwhile,the change law of value of z and φ is closely related to the crack evolution characteristics in the different phases.With the increase of the damage degree,the values of z and φ increase consistently in same rate.There is certain linear relationship between the initial value of z，φ and the strength.The method of crack detection and damage assessment by the electrochemical parameters may come true.
