## 4 Discussion  
The preparation or mobilization of natural soil in order to mix it with a stabilizer can play an important role in obtaining a uniform soil-binder mixture. The methodology adopted to optimize a suitable disintegration time is based on two types of assessment. The first is a visual assessment, as noted above. The second assessment is based on improving the grain size distribution curves and obtaining smaller sized particles after the disintegration process. The median diameter (D\({}_{50}\)) is considered in the evaluation. D\({}_{50}\) represents the diameter of soil particle (in mm) corresponding to 50% of the sample's passing percentage, which splits the curve with half above and half below this diameter. Soil 1 was classified as sandy clayey silt with medium plasticity. The soil water content was below the liquid limit. The median particle diameter (D\({}_{50}\)) was 13 mm for the non-homogenized soil specimen (Figure 8). For the wet soil specimens, the D\({}_{50}\) decreased to 5.5, 4 and 9.5 mm after the soil was homogenized for 10, 16 and 30 s, respectively. When the disintegration time was increased in several steps up to 120 s, the D\({}_{50}\) was increased to 16 mm. For the air-dried specimens, the D\({}_{50}\) was about 3 mm after the soil was homogenized for a 17 s disintegration time (Figure 9). The passing percentage was almost the same for the wet and air-dried specimens at a low disintegration time (less than 17 s) and high for wet specimens compared to the air-dried specimens when the disintegration time was increased to 30 s. This can be related to the medium plasticity properties of the soil in addition to the water content being below the liquid limit of the soil. When the soil particles agglomerated and adhered together at a high disintegration time, it became difficult to break them up again during the sieving process and they tended to stick in the opening of the sieve. The ideal disintegration time for Soil 1 ranged between 10 and 20 s and should not exceed 30 s.  
Soil 2 was classified as silty clay with high plasticity. The soil water content was almost half of the liquid limit. After the natural soil was homogenized for 10 s, the D\({}_{50}\) ranged between 11 and 7.5 mm for wet and air-dried specimens, respectively. When the disintegration time was increased to 13 s, the D\({}_{50}\) was increased to 10.5 mm for the air-dried specimens. The passing percentage for air-dried specimens was higher compared to the wet specimens at 10 and 13 s disintegration times. This could be ascribed to the high plasticity property of the soil, which made the wet soil particles adhere to each other and stick in the sieve openings. The proper disintegration time for Soil 2 ranged between 10 and 13 s and should not exceed 16 s.  
Soil 3 was classified as silty clay with medium plasticity. The soil water content was at the liquid limit of the soil. The D\({}_{50}\) was 16 mm for the non-homogenized soil specimen. After the natural soil was homogenized for 6 s, the D\({}_{50}\) decreased to 10 and 14 mm for the air-dried and wet soil specimens, respectively. When the disintegration time was increased to 12-13 s, the D\({}_{50}\) ranged between 10 and 11 mm for the wet and air-dried soil specimens, respectively. The D\({}_{50}\) increased to 16 mm when the disintegration time was further increased to 22-25 s. At 6 seconds disintegration time, the passing percentage for the air-dried specimens was higher compared to the wet specimens. This can be explained by the wet soil sample becoming stuck in the sieve openings (and thus not passing to the next sieve) due to the high moisture content and medium plasticity properties of Soil 3. The proper disintegration time for Soil 3 ranged from 6 to 13 s and should not exceed 22 s.  
Soil 4 was classified as silt with low plasticity.