Figure 1
Gradation curve of the sand.
Source: From ref. [39].
Table 1
Physical properties of the cement object.
| Object | Range | |
|---|---|---|
| Autoclave | 0.2 | |
| Blian | ||
| Setting time (min) | ||
| Initial | 120 | |
| Final | 180 | |
| Compressive strength (MPa) | ||
| 3 days | 220 | |
| 7 days | 320 | |
| 28 days | 400 |
Source: From ref. [39].
Table 2
Physical properties of the fiber.
| Typing | Fiber type I | Fiber type II |
|---|---|---|
| Material | Micro-synthetic | Macro-synthetic |
| Tensile strength | 4,000,000 | 570,000–660,000 kPa |
| Diameter | 23 μm | 300 μm |
| Aspect ratio | 600–1,200 | 30–120 |
| Number per kg | <100,000,000 | 53,800 |
| Color | Glossy | Gray |
Source: From ref. [39].
Figure 2
Split cylindrical mold.
Source: From ref. [39].
Figure 3
Specimen geometry.
Source: From ref. [39].
Table 3
Summary of uniaxial tensile strength test results in the present study.
| CCa | FCb | TFc | T f (kPa) |
|---|---|---|---|
| 3 | 0 | — | 44 |
| 3 | 0.5 | I | 41 |
| 3 | 0.5 | II | 39 |
| 5 | 0 | — | 104 |
| 5 | 0.5 | I | 95 |
| 5 | 0.5 | II | 90 |
aCement content (%), bFiber content (%), and cfiber type.
Source: From ref. [39].
Figure 4
Schematic diagram of the triaxial tensile test device Tf (kPa).
Source: From ref. [39].
Figure 5
Triaxial tensile test device.
Source: From ref. [39].
Table 4
Summary of triaxial direct tension test results in the present study.
| CC | FC | TF | CPa | Devatoric stress (kPa) | Mean stress (kPa) | Volumetric strain (%) | Axial state (%) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| At failure | Residual state | At failure | Residual state | At failure | Residual state | At failure | Residual state | ||||
| 3 | 0 | — | 100 | −196 | −104 | 35 | 65 | −0.037 | −0.45 | −0.41 | −1.07 |
| 3 | 0 | — | 200 | −277 | −191 | 108 | 136 | 0.035 | −0.86 | −0.45 | −1.32 |
| 3 | 0 | — | 300 | −365 | −278 | 178 | 207 | 0.029 | −0.22 | −0.49 | −0.89 |
| 3 | 0 | — | 300 | −364 | −282 | 179 | 206 | 0.060 | −0.10 | −0.46 | −0.73 |
| 3 | 0.5 | I | 100 | −172 | −160 | 43 | 47 | −0.601 | −1.61 | −0.61 | −0.51 |
| 3 | 0.5 | I | 200 | −258 | −240 | 114 | 120 | −0.303 | −1.21 | −0.66 | −2.18 |
| 3 | 0.5 | I | 300 | −311 | −293 | 196 | 202 | −0.031 | −1.35 | −1.00 | −3.26 |
| 3 | 0.5 | I | 200 | −245 | −222 | 118 | 126 | −0.330 | −1.45 | −0.77 | −2.33 |
| 3 | 0.5 | — | 100 | −148 | −123 | 51 | 59 | −1.800 | −1.80 | −1.40 | −4.50 |
| 3 | 0.5 | — | 200 | −239 | −192 | 120 | 136 | −1.050 | −1.43 | −2.06 | −4.39 |
| 3 | 0.5 | — | 300 | −320 | −292 | 193 | 203 | −1.190 | −1.60 | −2.51 | −1.76 |
| 5 | 0 | — | 100 | −211 | −95 | 30 | 68 | −0.229 | −0. 66 | −0.58 | −1.01 |
| 5 | 0 | — | 200 | −346 | −164 | 85 | 145 | −0.100 | −0.63 | −0.44 | −1.25 |
| 5 | 0 | — | 300 | −431 | −240 | 156 | 220 | −0.050 | −0.53 | −0.56 | 1.46 |
| 5 | 0 | — | 200 | −316 | −172 | 95 | 143 | −0.090 | −0.43 | −0.42 | −1.22 |
| 5 | 0 | — | 300 | −450 | −232 | 150 | 223 | −0.050 | −0.33 | −0.56 | −1.47 |
| 5 | 0.5 | I | 100 | −186 | −165 | 38 | 45 | 0.110 | −1.62 | −0.55 | −3.02 |
| 5 | 0.5 | I | 200 | −333 | −313 | 89 | 96 | 0.120 | −0.99 | −0.38 | −3.03 |
| 5 | 0.5 | I | 300 | −406 | −369 | 165 | 177 | 0.110 | −1.06 | −0.70 | −5.54 |
| 5 | 0.5 | II | 100 | −191 | −157 | 36 | 48 | −2.160 | −2.68 | −0.68 | −9.97 |
| 5 | 0.5 | II | 200 | −299 | −267 | 100 | 111 | −1.860 | −2.00 | −05.86 | −11.56 |
| 5 | 0.5 | II | 300 | −364 | −328 | 179 | 191 | −0.900 | −1.80 | −8.89 | −12.09 |
| 5 | 0.5 | II | 200 | −322 | −256 | 93 | 115 | −2.150 | −3.10 | −4.77 | −7.20 |
Source: From ref. [39].
Figure 6
Fracture mode: (a) CP = 300 kPa, CC = 3.0%, and FC = 0.0%; (b) CP = 300 kPa, CC = 5.0%, and FC = 0.0%; (c) CP = 200 kPa, CC = 3.0%, and FT = TYPE I; (d) CP = 300 kPa, CC = 5.0%, and FT = TYPE II; (e) CP = 100 kPa, CC = 3.0%, and FT = TYPE II; and (f) CP = 200 kPa, CC = 5.0%, and FT = TYPE II.
Source: From ref. [39].
Figure 7
Stress–strain and volume change behavior with 3.0% cement: (a) FC = 0.0%; (b) FC = 0.5% and TF = I; and (c) FC = 0.5% and TF = II.
Source: From ref. [39].
Figure 8
Stress–strain and volume change behavior with 5.0% cement: (a) FC = 0.0%; (b) FC = 0.5% and TF = I; (c) FC = 0.5% and TF = II.
Source: From ref. [39].
Figure 9
The effects of brittleness index versus confining pressure and type of fiber: (a) CC = 3.0% and (b) CC = 5.0%.
Source: From ref. [39].
Figure 10
Changes in tensile strength against confining pressure and type of fiber: (a) CC = 3.0% and (b) CC = 5.0%.
Source: From ref. [39].
Figure 11
Axial strain changes in failure stress with changes in confining pressure and type of fiber: (a) CC = 3.0% and (b) CC = 5.0%.
Source: From ref. [39].
Figure 12
Changes in initial stiffness and stiffness at 50% tension strength of samples with 5% cement with changes in confining pressure and type of fiber.
Source: From ref. [39].
Figure 13
Changes in energy absorption up to failure point versus effects of fiber diameter.
Source: From ref. [39].
Figure 14
Changes in normalized absorbed energy compared to axial strain with the effect of fiber diameter.
Source: From ref. [39].
Figure 15
Failure envelopes for cement-treated sand reinforced with fibers compared to the percentage of cement: (a) CC = 3% and (b) CC = 5%.
Source: From ref. [39].
Figure 16
Changes in (a) the cohesion intercept and (b) internal friction coefficient compared to the fiber dimensional ratio.
Source: From ref. [39].
Figure 17
Changes in the main stress ratio in (a) peak stress and (b) residual stress.
Source: From ref. [39].