Table 2.
Summary of properties of the soil natural Dutch soil used in this study
| Properties | Value | Method | Standard/Reference |
|---|---|---|---|
| Predominant clay minerals [wt%] | Smectite (37.2), illite/smectite (35.1) | XRD (< 0.002 mm) | In-house protocol, Qmineral |
| Grain size distribution | |||
| Clay (< 0.002 mm) [wt.%] | 14.8 | Hydrometer | ISO 17892–4 [24] |
| Silt (0.002–0.074 mm) [wt.%] | 16.5 | Wet sieving | |
| Sand (0.075–4.74 mm) [wt.%] | 68.5 | Wet sieving | |
| Fine gravel (4.75–6.74 mm) [wt.%] | 0.2 | Wet sieving | |
| Atterberg limits | |||
| Liquid Limit [%] | 28.8 | Falling cone | ISO 17892–6 [25] |
| Plastic Limit [%] | 15.2 | Thread | ISO 17892–12 [26] |
| Plasticity Index [LL-PL] | 13.6 | ||
| Unified soil classification system | CL (inorganic clay of low to medium plasticity) | ||
| Natural water content [%] | 3.5 | Oven drying at 105 °C | ISO 17892–1 [27] |
| Compaction characteristics | Standard proctor | BS EN 13286–2 [28] | |
| Maximum dry density [kg/m3] | 1980 | ||
| Optimum Moisture content [%] | 11.1 | ||
| Specific Gravity | 2.6887 | Ultrapycnometer | ISO 17892–3 [29] |
| pH | 7.36 (21 °C) | pH meter | * |
| Cation exchange capacity (meq/100 g) | Co (III)-hexamine | Bardon et al. [30] | |
| Bulk | 9.6 | ||
| Clay (< 0.002 mm) | 78.7 | ||
| Loss on ignition [%] | 1.15 | Heating at 550 °C | BS EN 15935 [31] |
*1 part of soil was mixed with 5 parts of demineralised water (accounting for 3.5% water content in the soil), stirred magnetically for 5 min, and the pH measured after 10 s