Abstract: The influence of water content variation on the resistance and piezoresistivity of multi-wall carbon nanotube reinforced mortar was investigated by means of four times drying and three times wetting experiments. The results were compared with the cement mortar. It showed small impact on resistance and piezoresistivity of specimen with more water content. With decreasing water content, the change of resistance became significant, especially for the cement mortar. The magnitude of the piezoresistivity of composites became large. The piezoresistivity of CM was more sensitive to the change of water than MWCNTs/CM in this case. Moreover, the magnitude of piezoresistivity near the percolation during the wetting process was higher than the drying process. Finally, the mechanisms of piezoresistivity change of MWCNTs/CM were analyzed during the process. The equivalent circuits were obtained to explain the change of conductive network.
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