Cement-based smart sensors appear particularly suitable for monitoring applications, due to their self-sensing abilities,
their ease of use, and their numerous possible field applications. The addition of conductive carbon nanofillers into a
cementitious matrix provides the material with piezoresistive characteristics and enhanced sensitivity to mechanical
alterations. The strain-sensing ability is achieved by correlating the variation of external loads or deformations with the
variation of specific electrical parameters, such as the electrical resistance. Among conductive nanofillers, carbon
nanotubes (CNTs) have shown promise for the fabrication of self-monitoring composites. However, some issues related
to the filler dispersion and the mix design of cementitious nanoadded materials need to be further investigated. For
instance, a small difference in the added quantity of a specific nanofiller in a cement-matrix composite can substantially
change the quality of the dispersion and the strain sensitivity of the resulting material. The present research focuses on
the strain sensitivity of concrete, mortar and cement paste sensors fabricated with different amounts of carbon nanotube
inclusions. The aim of the work is to investigate the quality of dispersion of the CNTs in the aqueous solutions, the
physical properties of the fresh mixtures, the electromechanical properties of the hardened materials, and the sensing
properties of the obtained transducers. Results show that cement-based sensors with CNT inclusions, if properly
implemented, can be favorably applied to structural health monitoring.
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