Study of hydration and hardening processes of self-sensing cement-based materials with carbon black content

In this paper was assessed the influence of carbon black (CB) powder on the hydration and hardening processes of Portland cement (PC)-based materials; this type of materials is designed to be used as cement-based sensors in structural or pavement health monitoring. The rate of PC hydration and hardening processes is influenced by the amount of CB addition, with direct consequences on some properties of these materials, i.e., water for normal consistency and setting time. These results coupled with those obtained by thermal and X-ray diffraction analyses suggest a delaying effect of PC hydration and hardening processes in the presence of carbon black powder, most likely as a result of CB nanoparticles high adsorbent surface. Compressive strength values of PC mortars with CB content up to 1 mass%, assessed after 28 days of hardening, are comparable with those of PC mortars; thus, these materials can be successfully used in construction.