Pressure sensitivity of multiscale carbon-admixtures–enhanced cement-based composites

The pressure-sensitive cement-based composites added with multiscale carbon materials, that is, carbon blacks, carbon fibers, and carbon nanotubes are investigated. In the article, the sensing property of cement-based composites with seven different proportions of carbon blacks, carbon fibers, and carbon nanotubes under cyclic loading is discussed and then the optimized formula among these seven proportions is chosen to investigate the influences of temperature and saturation degree on its sensing properties. In addition, the maximum perceivable frequency of multiscale carbon-admixtures–enhanced cement-based composite is obtained from the experimental results. The results indicate that the fractional change in resistance of the cement-based sensing composites increases at first and then decreases with the increase of temperature, but decreases with the increase of humidity. Additionally, the fractional change in resistance has a decrease with the increase of loading frequency, and the cement-based sensing composites prepared can perceive the biggest loading frequency of 0.5 Hz.