Piezoelectric behavior of polarized fresh cement pastes under the effect of different direct current voltages

Abstract

This study investigates an innovative polarizing technique that can enhance the piezoelectric behavior of Portland cement pastes. This technique utilizes a direct current (DC) during the initial curing stage to polarize the cement paste. The simplicity of this technique makes it attractive for future real-world applications, especially in the structural health monitoring (SHM) field. The scope of this work is to study the effect of the mixing water, and different curing voltages on the piezoelectric behavior of a total of 24 specimens. 12 specimens were prepared by mixing the cement with deionized (DI) water and other 12 specimens with tap (T) water. 3 T specimens and 4 DI specimens were not cured under the effect of DC to serve as reference. The rest of the specimens were cured under different voltages, namely: 5 V, 10 V, and 25 V. All the specimens were tested under cyclic compression loading that oscillates between 3 kN and 12 kN, and the produced piezoelectric voltage was recorded. The cyclic loading was applied on the faces that are parallel to the polarizing direction for all the treated specimens. The results show that the DC curing of cement pastes produces denser specimens. In addition, the DC curing increases the produced piezoelectric voltage for the T specimens. The g33 when compared to the reference specimens demonstrated an increase of approximately 163%, 134%, and 143% when cured under the effect of 5 V, 10 V, and 25 V, respectively. However, mixing with deionized water approximately eliminates the piezoelectricity of the cement paste.