The damage evolution of concrete is a process during which internal cracks emerge and propagate, and correspondingly the electromagnetic properties of concrete is changed according to the degree of damage development. In order to figure out the relationship between mechanical properties and electric behaviors as well as the propagation properties of electromagnetic waves during the damaging or failure of reinforced concrete members, a reinforced cement paste coaxial component (reinforced cement paste coaxial component, RCPCC) was designed based on the principle of coaxial cable, in which cement paste was regarded as the dielectric for its homogeneousness. The inner bar and outer reinforcement cage were used as conductors. According to the basic principles of electromagnetism, the finite element analysis on RCPCC was carried out. Following that, the simplified equivalent circuit model of the components with different damage levels and the corresponding electrical parameter expressions that can characterize the structural properties of RCPCC were established. Based on this model, the effect of the damage degree on alternating current circuit parameters (series impedance value, series capacitance and phase angle value) of component was analyzed. Furthermore, the bending and shearing failure experiments on RCPCC were carried out. The alternating current circuit parameters of the component during the bending and shearing failure process were measured by LCR instrument. Meanwhile, the spectrum analyzer was used to record the variation of the fundamental peak during the testing. The results show that the bending and shearing failure process of RCPCC could be divided into three phases, and the change of electromagnetic property value of each phase was different. The changing rate of the measured electrical parameters was consistent with the damage evolution rate. Consequently, there was an intrinsic connection between mechanical properties and electrical behaviors during the failure process. With the propagation of cracks, series impedance value increased, while series capacitance and phase angle value decreased. With the internal crack development of the component, the obstruction of the electromagnetic wave propagation reduced, resulting in the increase of fundamental peak. The damage degree of the component could be characterized by fundamental peak. The laws conducted by the results of testing were in good agreement with the analysis results of theoretical model, which verified the reliability of the model.
