## 4 Results and Discussion
### Mineralogy of PG Amended Lime-Stabilized Soil  
Figure 6a-c shows the XRD scatter pattern of the soil specimens stabilized with their respective optimum dosages of PG. At the outset, it is clear from the scatter patterns that there is no sign of any significant change in the general pattern of the diffraction peaks in all three combinations. The increase in strength of the stabilized soil is due to the formation of calcium silicate hydrate minerals as seen from the XRD peaks of all three combinations of the stabilized composite. The formation of calcite also acts as a minor contributor to the development of the strength of the stabilized soil. The presence of quartz and montmorillonite from the original soil is also detected in the XRD patterns. However, a keen observation of the three patterns reveals that there are subtle differences in the diffraction patterns. An obvious difference is in the intensity of the most prominent peak of quartz in all three combinations. It is clear that the intensity of the specific peak at around 26.5\({}^{\circ}\) is different for the three combinations. To better understand the differences in the patterns a microanalysis of the peak intensities of the identified prominent peaks was performed. The prominent minerals identified in the virgin soil were quartz and montmorillonite at 2-theta angles of 20.8\({}^{\circ}\), 26.6\({}^{\circ}\), 39.4\({}^{\circ}\), 40.2\({}^{\circ}\), 50.1\({}^{\circ}\), 68.3\({}^{\circ}\) and 19.8\({}^{\circ}\), 27.9\({}^{\circ}\), respectively. The pozzolanic reactions resulted in the formation of new minerals like ettrinigite, CSH and calcite. Ettrinigite was detected at a 2-theta value of 35.2\({}^{\circ}\) whereas CSH  
Figure 5: The brittleness Index of the lime-stabilized soil with and without PG. was detected at 2-theta values of 23.5\({}^{\circ}\), 29.3\({}^{\circ}\), 54.8\({}^{\circ}\) and 59.9\({}^{\circ}\). Calcite was detected at a 2-theta value of 36.5\({}^{\circ}\). The original intensity of quartz at 26.6\({}^{\circ}\) was 16,904 counts. However, this value was greatly reduced due to the stabilization process in the three combinations considered. For LP1, the intensity of quartz corresponding to 26.6\({}^{\circ}\) was 6681. This clearly indicates that the crystal structure of quartz is destroyed during the pozzolanic reactions, leading to the formation of new minerals. This intensity for LP2 was only 5496. This clearly indicates that there is better progress in pozzolanic reactions due to the increased lime and PG content, resulting in a reduction in the intensity of the quartz peak. For LP3, however, this intensity was 8950, which is comparatively higher than LP2. Thus, the destruction of quartz peaks is not as effective as in LP2. Similar behavior was also observed for the other quartz peaks as well. For the quartz peak at 20.8\({}^{\circ}\), the intensity reduced from 4364 counts to 2114, 1968 and 2069 counts for LP1, LP2 and LP3, respectively. Thus, there is a clear indication that there is effective progress of pozzolanic reaction in LP2 when compared to the other two combinations as seen from the reduced peak intensities of quartz. Looking at the intensities of montmorillonite, it is 2278 at 2-theta of 19.8\({}^{\circ}\) for the virgin soil whereas this reduced to 1182, 1193 and 1262 counts for LP1, LP2 and LP3, respectively. However, the peak intensities do not differ sufficiently to gain a clear interpretation. At the other peak of 27.9\({}^{\circ}\), the intensities reduced from 4825 to 2003, 1639 and 2362, respectively, for LP1, LP2 and LP3. Thus, in the case of montmorillonite as well, it is seen that there is a reduction in peak intensities of the mineral, indicating the effective progress of pozzolanic reactions, especially in LP2. Taking a look at the peak intensities of the minerals formed as a result of the pozzolanic reactions like ettrinigite, the intensity of ettrinigite increased with an increase in the lime content in the combinations.