Self-Sensing Capabilities of Cement Pastes Treated by Direct Current Curing Technique

In this study, an innovative curing technique, that is able to polarize the ions inside cement pastes is investigated. This technique is curing the cement paste while applying a direct current (DC). A total of 6 cement paste cubes were casted, 3 of them were not treated so it will serve as a reference and other 3 were cured while applying 25 V DC on two opposite sides of the specimen. All specimens were tested under different amplitude cyclic loading and the produced piezoelectric voltage was recorded. The results show that this technique was able to increase the produced piezoelectric voltage of the treated cement paste specimens when compared to the reference ones. In addition, the produced piezoelectricity showed a proportional behavior to the applied loads, which indicates the capabilities of self-sensing of the treated specimens. The voltage sensitivity values of the both the reference specimens and the treated ones are 0.34 and 1.77 mV/kN, respectively. The effect of the trapped moisture inside the specimens was also investigated, and the results show that the piezoelectricity greatly depends on the existence of moisture inside the specimens.