Ecomposition of calcium hydroxide (Ca(OH)two CaO H2 O) and calcium carbonate (CaCO3 CaO CO2 ), respectively [402]. The mass Sustainability 2021, 13, x FOR PEER REVIEWloss in these regions is usually utilised to decide the Ca(OH)two and CaCO3 content. 9 of 16 It can be worth mentioning that calcite (CaCO3 ), a carbonation item, tends to lower the mortars’ strength.Figure six. The TGA and DTA curves ofof mortars subjected to curing periods an internal atmosphere for 30 daysdays (a,b) Figure six. The TGA and DTA curves mortars subjected to curing periods in in an internal environment for 30 (a,b) and 360 daysdays (c,d). Each of the samples were heated using a heating rateof 12.five C/min-1 and as much as 1000 C a nitrogen gas and 360 (c,d). All the samples have been heated using a heating price of 12.5 /min-1 and as much as 1000 in within a nitrogen atmosphere. gas atmosphere.A rise in loss was observed for all samples studied right after 360 days of aging inside the internal environment (Figurecurves This outcome aged be relatedin an external environFigures 7a,b show the DTA 6c,d). of mortars may well naturally towards the exposure with the mortars towards the ambient air, causing carbonation in the reaction with CO2endothermic ment for 90 days (Figure 7a) and 512 days (Figure 7b). For all compositions, . In fact, the intensity of observed at about 156 and 215 , that are connected to (CaCO3 ) increases peaks were the endothermic peaks connected to calcite decomposition ettringite and AFm with time (see Figure 6b,d). Furthermore, the intensity of your endothermic peaks, from the (hemicarbonate and monocarbonate) phases, respectively [39,43]. It really is recognized that calcined ML-SA1 Purity & Documentation dehydroxylationto silicon, features a higher IQP-0528 supplier content material of alumina in its compositionThis indicates KR, additionally of portlandite (Ca(OH)2 ) decreased substantially with time. (see Table 1). that portlandite was consumed by the carbonation reaction. are in all probability connected with Thus, the presence of hemi and monocarbonate compounds For M0 reaction of calcite (CaCO3) from lime, as well as the area (i.e, the zone related the chemical(mortar with no KR) the mass loss within the fourthextra alumina present in the to calcite decomposition) was about 18.6 and important30 days and 360 days, system is likely because of the addition of kaolin residue. It is actually 32.7 , at to emphasize that the respectively. On the other hand, monocarbonate with KR (M5, M10, M15,formation of monosulfate, formation of hemi and for the samples compounds inhibits the M20, and M30) the losses in thisettringite remains inside the the selection of longer time frame [44]. The30 and 360 hemi, so the area were smaller, in system for any 9.91.6 and 30.41.six , at ettringite, days. and monocarbonate phases occupy a higher volume of solid hydrates inside the mortar pores compared to monosulfates, therefore encouraging the filling up of voids plus the attainment of mechanical strength [45]. Intense peaks at 46180 and 750 were also observed, which are connected with portlandite and calcium carbonate. This indicates that all mortars present an excessSustainability 2021, 13,9 ofThis indicates that the formation of CSH was likely favored in the samples with calcined KR and, as a consequence, the carbonation impact was reasonably moderate. Figure 7a,b show the DTA curves of mortars aged naturally in an external environment for 90 days (Figure 7a) and 512 days (Figure 7b). For all compositions, endothermic peaks had been observed at about 156 C and 215 C, which are connected to ettringite and AFm Sustainability.