Research Article

Cement Pastes and Mortars Containing Nitrogen-Doped and Oxygen-Functionalized Multiwalled Carbon Nanotubes

Figure 8

(a)–(h) SEM images of the hydrated cement paste during the initial hours of the hydration process. The image in (b) corresponds to a close up of (a), showing a carbon nanotube joining two hydrated cement grains (see the enclosed zone). (c) Carbon nanotubes embedded in cement grains. (d) Long carbon nanotube stretched by two cement grains. (e) Cement grains at an early age, growing on a tangle of nanotubes. (h) Cement grains with ettringite bar-shaped structures growing on their surface. The arrows indicate different carbon nanotubes within the cement paste.