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 degrees 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 x 10(-3) Vm/N, which are the promising characteristics for its potential use in the smart civil engineering structures. (C) 2010 Elsevier B.V. All rights reserved.