## 5 Results and Discussion
### Modeling Results and Analysis
#### 5.3.1 Influences of the Admixtures on the Chemical States of the Compositional Minerals
By adding proper doses to the cement-stabilized soils, the increased alkalinity accelerated the reactant dissolution, thereby promoting the formation of cement hydrates and pozzolanic products and thus improving the UCS performance. In the case of excessive doses, the further increased alkalinity promoted the dissolution of the soil minerals and the formation of the pozzolanic products, but the dissolution of the calcium-based clinkers was inhibited due to the excessively dissolved ions with smaller radii (Table 4), thereby limiting the hydrate formation and the growth of UCS. These facts aligned with the previous knowledge [1,42] that the performances of cement-stabilized soils are highly dependent on the total amount of CSH. Note that the supersaturation level of CSH in the JA12 specimen still exceeded that in the CS specimen within 10 h. This phenomenon was due to the acceleration effects of the high alkalinity on the reactant dissolution, during which the pore solution was unsaturated in the very early stages of the reaction. Regarding the effects of PNS, it was clear that increasing the dose substantially inhibited montmorillonite dissolution and natrolite formation, with natrolite becoming unsaturated at 5 h. This fact was ascribed to the hydrophobic layer that was generated by the adsorbed PNS molecules on the montmorillonite [15]. The overall dissolution of C\({}_{3}\)S and the saturation levels of CSH and AFt were increased by the PNS addition, but the increments first increased and then decreased as the PNS dose increased from 1.2% to 1.8%. This result indicated the preferential adsorption of PNS on montmorillonite over the clinkers, which first retarded the pozzolanic reaction of montmorillonite and then the cement hydration. Notably, the early saturation levels of CSH and AFt were reduced by adding PNS due to the adsorbed PNS molecules on the clinker surfaces. 3.2 The Correlation Analysis of the Saturation Levels between Ca(OH)\({}_{2}\) and the Investigated Products  
Figure 4 shows the correlation between the _SI_ values of Ca(OH)\({}_{2}\) and those of CSH, AFt and natrolite since the saturation level of Ca(OH)\({}_{2}\) with respect to the pore solution was regarded as an indicator for the hydration rate of the clinkers [43]. The correlational analysis showed that the _SI_ values of CSH and AFt grew linearly with those of Ca(OH)\({}_{2}\), indicating that the cement hydration was promoted by the increasing Ca(OH)\({}_{2}\) saturation within the pore solution. However, the R\({}^{2}\) of CSH was relatively low due to the uptake of aluminum and sodium in the low Ca/Si CSH. The saturation levels of natrolite were poorly correlated with those of Ca(OH)\({}_{2}\), with the _SI_ value of natrolite having a positive proportional relationship with those of the JA series and PNS series. This fact was ascribed to the distinguished modification mechanisms of JA and PNS in the dissolution of the soil minerals, which were clarified by the above analyses. Considering that the permanent negative layer charge of soil minerals can consume the Ca\({}^{2+}\) and CaOH\({}^{+}\) that is released by the clinker dissolution, the correlation analysis further suggested that the Ca(OH)\({}_{2}\) saturation was directly altered by the JA dissolution and was indirectly altered by the adsorption layer of PNS on the soil mineral surfaces. It is worth mentioning that the highest Ca(OH)\({}_{2}\) SJ was \(-\)0.8, while under the same cement addition conditions, [PERSON] et al. [25] detected supersaturated Ca(OH)\({}_{2}\) in cement-stabilized soils with low cation exchange capacities (\(\leq\)32 meq/100 g), which had a higher strength than those with undersaturated Ca(OH)\({}_{2}\) and high cation exchange capacities. Hence, the authors suggest that the cation exchange process of the soil minerals was primarily ascribed to the undersaturation of Ca(OH)\({}_{2}\) and the slow strength increase in the cement-stabilized soils.