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Fig. 9.
Physical characteristics of engineering excavated soil
| Type | Water content (%) | Density (g/cm3) | Liquid limit (%) | Plastic limit (%) | Plasticity index (%) |
|---|---|---|---|---|---|
| A | 28.8 | 1.94 | 39.9 | 21.7 | 18.2 |
| B | 23.2 | 1.98 | 38.9 | 20.9 | 18.0 |
| C | 26.6 | 1.95 | 35.3 | 20.6 | 14.7 |
Basic properties of fly ash
| Fineness (%) | Chloride ion content (%) | Water demand ratio (%) | Loss on ignition (%) | Sulfur trioxide (%) | Water content (%) |
|---|---|---|---|---|---|
| 19.8 | 0.014 | 102 | 2.38 | 0.79 | 0.11 |
Mixing ratio of the fluidized solidified soil
| Number | Type of soil | Soil (kg) | Cement (kg) | Fly ash (kg) | Quicklime (kg) | Water (kg) | Slump (kg) |
|---|---|---|---|---|---|---|---|
| A-1 | A | 800 | 60 | 60 | 0 | 736 | 240 |
| A-2 | A | 800 | 60 | 45 | 15 | 736 | 235 |
| A-3 | A | 800 | 60 | 30 | 30 | 736 | 220 |
| A-4 | A | 800 | 60 | 15 | 45 | 736 | 190 |
| A-5 | A | 800 | 60 | 0 | 60 | 736 | 180 |
| B-1 | B | 800 | 60 | 20 | 30 | 400 | 220 |
| C-1 | C | 800 | 60 | 30 | 30 | 294 | 220 |
Mass ratio (kg) and corresponding raw material carbon emission factor used in carbon emission calculation of different backfill materials [28–32]
| Backfill materials | Clay | Quicklime | Cement | Fly ash | Sand | Aggregate | Water | Water reducer | Foaming agent | Excavated soil |
|---|---|---|---|---|---|---|---|---|---|---|
| Lime-soil | 1120 | 360 | ||||||||
| C15 plain concrete | 168 | 82 | 840 | 1170 | 160 | 2.5 | ||||
| Foamed concrete | 332 | 812 | 358 | 0.23 | ||||||
| Fluidized solidified soil | 48 | 72 | 24 | 598 | 958 | |||||
| Carbon emission factor (kg CO2e/t) | 2.69 | 1190 | 735 | 8 | 2.51 | 2.18 | 0.168 | 28 | 1950 | 1.0 |
Chemical composition of cement (wt%)
| Materials | CaO | SiO2 | Al2O3 | Fe2O3 | MgO | SO3 | Alkali content | Loss |
|---|---|---|---|---|---|---|---|---|
| Cement | 59.09 | 22.82 | 6.98 | 2.25 | 2.33 | 2.27 | 0.70 | 3.08 |