Sensing Properties of Carbon Nanotube–Carbon Fiber/Cement Nanocomposites

In this work, carbon nanotubes (CNTs) were added into a carbon fiber cement system to produce carbon nanotube–carbon fiber/cement nanocomposites in the form of pastes. The compressive strength, morphology, pressure-sensitive properties, and temperature-sensitive properties were tested. The results show strengthening of the mechanical properties and pressure sensitivity as the CNT content increases from 0.2 % to 1.0 % by mass of cement. The addition of CNTs into cement paste also leads to enhancement of the temperature sensitivity. Additionally, microscopic observation shows that CNTs act as fillers, which results in a dense microstructure of cement paste. Test results indicate that the carbon nanotube–carbon fiber/cement composites show potential either as stress sensors for vehicle detection, weigh-in-motion measurement, and vehicle speed detection or as thermistors for temperature monitoring in concrete structures.