This work hypothesizes that mixing carbon nanotubes with cement improves the thermal and electrical properties of bulk cement composites. To test this, two different methods of combining cement and dispersed multi-walled carbon nanotubes (MWCNTs) were considered. In the first method, cement composites were produced by adding a dispersion of MWCNTs to cement. In the second, MWCNT-based thin films were spray-coated and combined with cement to produce cement composites. A third group of specimens was produced using both MWCNT dispersions and MWCNT film-coated. The experimental parameters considered were the mixing method, MWCNT concentrations, number of curing days, and voltages applied. Furthermore, field emission scanning electron microscopy revealed that the MWCNTs were evenly dispersed within the composites and formed a percolated network. Additionally, X-ray diffraction analysis confirmed that the products formed during hydration of the composites (i.e., C-H and C-S-H) were the same as those generated using ordinary mortar. Upon testing these mortar-based specimens, it was found that the cement composites formed using a combination of MWCNT dispersion and MWCNT-based films exhibited the highest heating performance and lowest electrical resistance. Finally, thermal imaging showed that increased MWCNT concentrations during specimen casting led to a corresponding increase in their surface temperature upon voltage application.

This study aimed to detect damage based on thermal and electrical resistance properties by fabricating composites in which multi-walled carbon nanotubes (MWCNTs) and cement-based materials are mixed. The experimental parameters used were the cement-based material type, MWCNT concentration, curing period, and presence of damage. The experimental results showed that damage in cement paste can be detected using the heat property at every MWCNT concentration, and damage in mortar can be detected at MWCNT concentrations of ≤0.25 wt%. However, damage to concrete is difficult to detect using the heat property. Damage to cement paste, mortar, and concrete can be detected at every concentration using the electrical resistance property. Furthermore, field emission scanning electron microscopy (FE-SEM) results revealed uniformly dispersed MWCNTs inside the composites without agglomeration or the formation of carbon nanotube (CNT) networks.