Preparation and properties of cement based piezoelectric composites modified by CNTs

In this study, cement based piezoelectric composites have been prepared from Portland cement with the addition of 70 vol.% of PZT powders and various amounts of modified CNTs ranging from 0 to 1.3 vol.%. The CNTs act as a conductive filler dispersed in the cement matrix, improving the poling efficiency of the composites and enabling the poling process to be carried out at room temperature, in contrast to the 120 °C required for the PZT/cement composites without CNTs. The addition of CNTs significantly enhanced the piezoelectric properties of the composites. With a CNT content of 0.3 vol.%, the CNTs/PZT/cement composite showed the highest piezoelectric strain factors ( d 33) of 62 pC/N and piezoelectric voltage factors ( g 33) 60 × 10 −3 Vm/N, which are the promising characteristics for its potential use in the smart civil engineering structures. ►A novel cement based piezoelectric composite containing CNTs and PZT was investigated for the first time. ►The CNTs improved the poling efficiency of the cement based composites and enabled the poling process to be carried out at room temperature. ►The addition of CNTs significantly enhanced the piezoelectric properties of the cement based composites. The piezoelectric strain factor of the composites modified by CNTs was 41% higher than that of the composites without the CNTs.