## 3 Results and Discussion
### Characterization of Constituent Materials
#### 3.2.3 Thermal Analyses of Binary and Ternary Cementitious Matrices (B1-B10)  
TG analyses were carried out at 7 and 28 days, the results of which are shown in Figures 11 and 12. It should be noted that initially the first nine bases were dry cured (B10 was only water cured), however none had carbonated since the CaCO\({}_{3}\) content is lower than the initial LS content in the paste. In addition to the thermal analyses carried out at day 7 and day 28, the three selected cementitious matrices (PC60 LS40, PC60 LS20 FA20 and PC43 LS20 FA37), were reproduced, water cured after day 1 and TG analyses were carried out at day 1, 7, 28 and 56. For PC60 LS40, TG analyses were carried out at day 90, as well. At this point, the Ca(OH)\({}_{2}\) consumption will be discussed (Table 7) in an effort to shed more light into the hydration processes. To begin with, it can be noticed that until day 28, that PC continues hydrating, the Ca(OH)\({}_{2}\) content of PC60 LS40 increased and from then after it remained almost constant. It can be claimed, therefore, that the presence of FA in PC60 LS20 FA20 increased the consumption of the Ca(OH)\({}_{2}\) content significantly over all ages. Figure 11: Ca(OH)\({}_{2}\) content of binary and ternary cementitious matrices. Figure 12: CaCO\({}_{3}\) content of binary and ternary cementitious matrices. As demonstrated in Table 7, PC60 LS40 at day 1 contained 7.5% Ca(OH)2 and 9.1% at day 7. For the first two pastes, PC60 LS40 and PC60 LS20 FA20, which have the same PC content, the rate of hydration of PC at day 1 and 7 is expected to be essentially unaltered. However, it can be observed that at early ages, the Ca(OH)2 content of PC60 LS20 FA20 is significantly lower, particularly at day 7. This is a strong indication that the pozzolanic activity of the FA present in this paste had already started by day 7, although it has been claimed that at high FA contents (PC45 FA55) other researchers had noticed Ca(OH)2 consumption by day 3 [38]. Nonetheless, FA content is one matter and PC content is another. For this, the authors have adopted the PC/FA ratio, which is more representative in thermal analyses, together with the full formulation dosages, since FA is feeding from the Ca(OH)2 produced during cement hydration. The following observations were drawn:  
* A paste containing 43%PC would be expected to generate 43/60 \(\times\) 7.5% = 5.4% Ca(OH)2 based on PC60 LS40 Ca(OH)2 content at day 1. * Also, a paste containing 43%PC would be expected to generate 43/60 \(\times\) 7.2% = 5.2% Ca(OH)2 based on PC60 LS20 FA20 Ca(OH)2 content at day 1. * As shown in Table 7, PC43 LS20 FA37 contained 4.0% Ca(OH)2 at day 1. This indicates that the pozzolanic activity of a part of the FA present in the paste had already commenced. * Inversely, a paste containing 43%PC would be expected to generate 43/60 \(\times\) 9.1% = 6.5% Ca(OH)2 based on PC60 LS40 Ca(OH)2 content at day 7. * A paste containing 43%PC would be expected to generate 43/60 \(\times\) 8.1% = 5.8% Ca(OH)2 based on PC60 LS20 FA20 Ca(OH)2 content at day 7. * As demonstrated in Table 7, PC43 LS20 FA37 contained 6.0% Ca(OH)2 at day 7. This indicates that the pozzolanic activity of a part of the FA present in the paste had progressed by day 7, but the reaction of the available FA particles could have been delayed. * Continuing this train of thought, a paste containing 43%PC would be expected to generate 43/60 \(\times\) 10.3% = 7.4% Ca(OH)2 based on PC60 LS40 Ca(OH)2 content at day 28. * Moreover, a paste containing 43%PC would be expected to generate 43/60 \(\times\) 8.2% = 5.9% Ca(OH)2 based on PC60 LS20 FA20 Ca(OH)2 content at day 28. * PC43 LS20 FA37 contained 5.9% Ca(OH)2 at day 28 (Table 7), implying that almost half of the FA was unreacted by day 28 since the amount of Ca(OH)2 was equal to that of PC60 LS20 FA20. * Also, a paste containing 43%PC would be expected to generate 43/60 \(\times\) 10.6% = 7.6% Ca(OH)2 based on PC60 LS40 Ca(OH)2 content at day 56.