## 3 Results and Analysis
### Phase Composition and Microstructure  
Figure 7 presents the XRD patterns of selected specimens from the SLM experiments along with their corresponding _UCS_ values and ISW proportions (SS:GGBFS:PS:CS). Significant variations in phase composition were observed among specimens with different ISW proportions. The characteristic diffraction peak around 2\(\theta\) = 29.5\({}^{\circ}\), attributed to C(-A)-S-H gel formation, is recognized as the primary contributor to the strength development of aeolian sand consolidation. Specimens NO. 4 and NO. 8 with low _UCS_ demonstrated attenuated C(-A)-S-H gel diffraction intensities. In contrast, specimens NO. 12 and NO. 11 with higher mechanical performance displayed enhanced peak intensities at this position, with specimen NO. 11 manifesting an additional characteristic peak, which indicates the increased gel formation--a phenomenon consistent with its elevated GGBFS content. Figure 6: Variations in E and _DI_ with _UCS_ for specimens. Ettringite diffraction peaks at 20 = 40\({}^{\circ}\) were detected in all specimens except specimen NO. 8, with specimen NO. 12 exhibiting supplementary ettringite-related peaks. This absence in specimen NO. 8 may be attributed to its higher SS content and reduced CS proportion, resulting in excessive Fe-phase oxides and diminished alkalinity within the system. These conditions potentially inhibited the synthesis of ettringite through the reaction pathway described in Equation (5):  
\[\mathrm{C_{3}A+3(CaSO_{4}\bullet 2H_{2}O)+2 Ca(OH)_{2}+24H_{2}O\to 3 CaO\bullet Al_{2}O_{3}\bullet 3 CaSO_{4} \bullet 32H_{2}O} \tag{5}\]  
Additionally, characteristic peaks of calcite (CaCO\({}_{3}\)) were identified, with their formation attributed to the carbonation of Ca(OH)\({}_{2}\) during the curing process. Similar to ettringite, calcite contributes to strength enhancement by filling the pores between particles and increasing the density of stabilized aeolian sand. The highest calcite peak intensities were observed in Specimens NO. 4, 11, and 26, while its diminished presence in Specim NO. 8 correlates with the absence of CS. However, despite their pronounced calcite content, Specimens NO. 4 and 26 exhibited suboptimal mechanical performance. This phenomenon may stem from the formation of weaker particle connections by the limited amount of C(-A)-S-H gel, which could be disrupted by the volumetric expansion caused by excessive calcite crystal generation. Figure 8 displays the TG and DSC curves of selected specimens in the SLM experiment. The TG curve quantifies mass loss during heating, enabling the clear comparison of hydrated phase contents across specimens due to distinct decomposition temperatures of different hydration products. Concurrently, the DSC curve monitors the heat flux differential between the sample and reference, providing insights into endothermic and exothermic events within the material. The combined analysis of TG-DSC data enhances the characterization of ISW hydration products in stabilized aeolian sand. Three prominent thermal mass loss stages can be observed in Figure 8: (a) 60-120 \({}^{\circ}\)C: Attributed to the loss of bound water from hydration products such as C(-A)-S-H gel and ettringite, corresponding to the P1 endothermic peak in the DSC curve; (b) 380-500 \({}^{\circ}\)C: Associated with hydroxyl group removal from Ca(OH)\({}_{2}\) in the matrix, marked by the P2 endothermic peak; and (c) 600-720 \({}^{\circ}\)C: Corresponding to the decomposition of carbonate phases (e.g., calcite). Specimens with lower _UCS_ such as specimens NO. 4 and 8 exhibited reduced mass loss and diminished peak areas in the first stage, indicative of limited gel and ettringite formation. Notably, Specim NO. 4 demonstrated significantly higher mass loss in the second stage, consistent with its elevated CS content, which also contributed to enhanced thermal decomposition  
Figure 7: XRD patterns of specimens in SLM experiment. (third-stage mass loss and peak area). Conversely, Specimen NO.