Effect of Pozzolanic Materials and Poling Field on Electromechanical Coupling Coefficient of Cement-Based Piezoelectric Composites

Abstract

Electromechanical coupling coefficient of cement-based piezoelectric composites affected by pozzolanic materials and poling field are investigated. Specimens, through a pressure approach, are manufactured by combining PZT powders and cement-based binder with the same volume fraction. Pozzolanic materials including fly ash, slag and silica fume replace 20% cement in the binder. Three poling fields are considered to induce piezoelectricity of 0-3 cement-based composites. Results show that electromechanical coupling coefficients do not have many fluctuations in terms of material ages for any cement-pozzolanic piezoelectric composites. With the same volumetric substitutes of pozzolanic materials, the electromechanical coupling coefficient with pozzolanic materials except fly ash is lower than that with plain cement, especially for silica fume having a 7.9% decrease. Raising poling field can increase electromechanical coupling coefficients. Polarization of cement-based piezoelectric composites containing silica fume in low poling fields such as 0.5kV/mm and 1kV/mm is not easy to complete.