*3.2. Di*ff*erential Thermogravimetric Analysis*

The DTG curves of the samples are displayed in Figures 4 and 5. The calcium hydroxide and carbonated species content %wt of the samples, measured at 28 days, are given in Table 4. The results were calculated from the TG curves.

At early age cement pastes analysis, the portlandite quantity represents the hydration of the calcium silicate compounds [27]. The curing conditions did not affect the content of neat cement pastes. By contrast, the nano-modified pastes presented lower portlandite content, compared to the references in both curing conditions. After 28 days in water immersion, the NC addition presented lower portlandite content and higher carbonates content. Like NL, the combination of nanoparticles (NSL) led to higher carbonated species content (Figure 4). The shifted peak temperature from 720 ◦C to 752 ◦C could indicate crystallinity modification of carbonates or the presence of additional carbonated species [28]. After 28 days of wetting-drying cycles, the portlandite content was found reduced compared to the reference, and the carbonates of NC-cement pastes were found increased (Figure 4).

Consequently, the curing conditions seem to strongly affect the quantities of portlandite and carbonates, depending on the nanoparticle that has been incorporated. This fact must be connected to the microstructure to verify the nanoparticles' behavior in different curing conditions in cement pastes.

**Figure 4.** DTG curves of neat cement paste and nano-modified cement pastes cured in water immersion, 28 days.

**Figure 5.** DTG curves of neat cement paste and nano-modified cement pastes cured under wetting-drying cycles at 28 days.


**Table 4.** Calcium hydroxide and carbonate species content, as a percentage by mass, at 28 days.
