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Chemical composition of Portland cement, fly ash, and slag powder (wt%)
| Constituent | CaO | SiO2 | Al2O3 | Fe2O3 | MgO | Na2O | SO3 | Loss |
|---|---|---|---|---|---|---|---|---|
| Cement | 63.71 | 20.35 | 5.0 | 3.3 | 1.37 | 0.39 | 2.48 | 2.6 |
| Fly ash | 2.4 | 61.9 | 28.8 | 2.5 | 0.8 | 0.3 | 0.6 | 1.7 |
| Slag powder | 38.1 | 30.0 | 13.6 | 0.6 | 7.6 | 0.3 | 0.3 | 4.6 |
Performance indices of Portland cement
| Indices | Density (g/cm3) | Consistence (%) | Stability | > 80 μm | Specific surface area (m2/kg) | Setting time (min) | Compressive strength (MPa) | |||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 day | 3 days | 28 days | ||||||||
| Cement | 3.08 | 21.35 | Qualified | 1.8 | 340 | 160 | 195 | 22.1 | 37.4 | 62.6 |
The influences of unmodified nanosilica, nanosilica suspension, silane coupler, and PCE content on the setting times of grouting pastes
| Composition | Content (wt%) | Setting time (min) | |
|---|---|---|---|
| Initial | Final | ||
| Reference | 0 | 660 ± 15 | 750 ± 20 |
| Unmodified nanosilica (nanosilica/binder) | 0.2 | 580 ± 20 | 660 ± 25 |
| 0.5 | 500 ± 15 | 570 ± 20 | |
| 0.8 | 460 ± 10 | 540 ± 20 | |
| 1 | 410 ± 20 | 470 ± 15 | |
| 1.5 | 340 ± 15 | 420 ± 20 | |
| 2 | 270 ± 10 | 350 ± 15 | |
| Nanosilica suspension (nanosilica/binder) | 0.2 | 640 ± 30 | 710 ± 25 |
| 0.5 | 590 ± 25 | 660 ± 20 | |
| 0.8 | 560 ± 25 | 630 ± 15 | |
| 1 | 650 ± 30 | 720 ± 20 | |
| 1.5 | 940 ± 40 | 1,010 ± 35 | |
| 2 | 1,590 ± 50 | 1,660 ± 40 | |
| Silane coupler (silane/nanosilica) | 0 | 500 ± 20 | 580 ± 20 |
| 4 | 540 ± 15 | 620 ± 15 | |
| 10 | 590 ± 20 | 670 ± 25 | |
| 20 | 910 ± 30 | 990 ± 30 | |
| 30 | 1,810 ± 45 | 1,880 ± 35 | |
| PCE (PCE/nanosilica) | 0 | 540 ± 10 | 620 ± 15 |
| 4 | 560 ± 15 | 640 ± 20 | |
| 10 | 580 ± 20 | 650 ± 15 | |
| 20 | 600 ± 15 | 670 ± 10 | |
| 30 | 620 ± 10 | 700 ± 20 | |
The effects of unmodified nanosilica, nanosilica suspension, silane coupler, and PCE content on the fluidity of grouting pastes
| Composition | Content (wt%) | Fluidity (mm) | |
|---|---|---|---|
| Initial | 30 min | ||
| Reference | 0 | 350 ± 4 | 325 ± 3 |
| Unmodified nanosilica (nanosilica/binder) | 0.2 | 355 ± 3 | 325 ± 5 |
| 0.5 | 335 ± 6 | 200 ± 2 | |
| 0.8 | 280 ± 2 | 180 ± 3 | |
| 1.0 | 250 ± 3 | 150 ± 4 | |
| 1.5 | 200 ± 2 | 130 ± 4 | |
| 2.0 | 150 ± 3 | 120 ± 2 | |
| Nanosilica suspension (nanosilica/binder) | 0.2 | 350 ± 6 | 345 ± 3 |
| 0.5 | 345 ± 5 | 335 ± 4 | |
| 0.8 | 335 ± 5 | 320 ± 5 | |
| 1.0 | 330 ± 4 | 300 ± 3 | |
| 1.5 | 310 ± 3 | 200 ± 2 | |
| 2.0 | 295 ± 3 | 165 ± 2 | |
| Silane coupler (silane/nanosilica) | 0 | 320 ± 4 | 230 ± 3 |
| 4 | 330 ± 4 | 320 ± 2 | |
| 10 | 350 ± 3 | 345 ± 5 | |
| 20 | 355 ± 4 | 355 ± 4 | |
| 30 | 355 ± 5 | 355 ± 3 | |
| PCE (PCE/nanosilica) | 0 | 340 ± 3 | 315 ± 4 |
| 4 | 350 ± 5 | 325 ± 3 | |
| 10 | 355 ± 3 | 330 ± 2 | |
| 20 | 350 ± 4 | 330 ± 4 | |
| 30 | 345 ± 2 | 330 ± 3 | |