Effects of CNT Doping Level and Water/Cement Ratio on the Piezoresistivity of CNTS/Cement Composites Available to Purchase

The carbon nanotubes (CNTs)/cement composites with different doping levels of multi-walled carbon nanotubes (MWNTs) and water/cement ratios are fabricated. By comparing the responses of electrical resistance of these CNTs/cement composites to compressive stress, the effects of MWNT doping level and water/cement ratio on the piezoresistive sensitivity of composites are investigated. Experimental results indicate that the piezoresistive sensitivities of CNTs/cement composites with 0.05 wt. %, 0.1 wt. % and 1 wt. % of MWNTs firstly increase and then decrease with the increase of CNT doping levels. The electrical resistance of CNTs/cement composites 0.6 water/cement ratio is more sensitive to compressive stress than that of composites with 0.45 water/cement ratio.