Figure 1.
Polypropylene fibres with 18 mm in length in the percentage of 0.1%, 0.2% and 0.3% given to the Proctor mould
Figure 2.
Grain-size distribution curves for tested soil samples
Figure 3.
Compaction curves of test samples I and II by both compaction method: standard Proctor (SP) and modified (MP)
Figure 4.
Compaction curves of grSa with additions of 1.5% cement and 0.2% or 0.3% of fibres by: (a) SP, and (b) MP methods
Figure 5.
Samples during CBR tests without and with an additional load of 2.44 kPa
Table 1.
Geotechnical parameters of the investigated soil
| Sample number | Material | ρs (g/cm3) | Compaction method | |||
|---|---|---|---|---|---|---|
| Standard Proctor | Modified Proctor | |||||
| wopt (%) | ρd max (g/cm3) | wopt (%) | ρd max (g/cm3) | |||
| I | grSa | 2.65 | 9.00 | 2.020 | 8.50 | 2.085 |
| grSa+1.5%C | 2.66 | 8.90 | 2.120 | 8.40 | 2.130 | |
| grSa+3.0%C | 2.66 | 8.80 | 2.140 | 8.30 | 2.150 | |
| grSa+4.5%C | 2.67 | 8.70 | 2.170 | 8.10 | 2.176 | |
| grSa+6.5%C | 2.68 | 8.50 | 2.182 | 7.90 | 2.190 | |
| II | grSa | 2.65 | 9.70 | 1.974 | 9,60 | 2.022 |
| grSa+0.1%F 18 mm | 2.65 | 9.80 | 2.003 | 8.80 | 2.104 | |
| grSa+0.2%F 18 mm | 2.65 | 8.00 | 2.054 | 7.50 | 2.158 | |
| grSa+0.3%F 18 mm | 2.65 | 7.70 | 2.060 | 7.00 | 2.160 | |
| grSa+1.5%C | 2.66 | 9.50 | 2.010 | 9.50 | 2.070 | |
| grSa+1.5%C+0.2%F 18 mm | 2.66 | 7.90 | 2.066 | 7.00 | 2.183 | |
| grSa+1.5%C+0.3%F 18 mm | 2.66 | 8.00 | 2.060 | 7.80 | 2.124 | |
[i] C – cement addition, F – fibre addition
Figure 6.
Dependence of the CBR values on the percentage addition of fibres for both compaction methods for sample II
Figure 7.
Relation of the CBR values on the percentage cement addition for both compaction methods: a) the standard Proctor, b) the modified Proctor
Table 2.
Results of the California Bearing Ratio test
| Sample number | Material | Curing time (days) | CBR (%) | |||
|---|---|---|---|---|---|---|
| Standard Proctor | Modified Proctor | |||||
| Unloaded | Loaded 2.44 kPa | Unloaded | Loaded 2.44 kPa | |||
| I | grSa | 0 | 40.8 | 43.3 | 58.2 | 99.5 |
| grSa+1.5%C | 0 | – | 11.0 | – | 28.0 | |
| 7 | – | 110.6 | – | 84.6 | ||
| 28 | – | 241.5 | – | 212.1 | ||
| grSa+3.0%C | 0 | – | 22.72 | – | 33.20 | |
| grSa+4.5%C | 0 | – | 31.21 | – | 35.99 | |
| grSa+6.0%C | 0 | – | 38.50 | – | 44.93 | |
| II | grSa | 0 | 19.8 | 21.0 | 53.9 | 68.3 |
| grSa+0.1%F 18 mm | 0 | – | 47.7 | – | 58.8 | |
| grSa+0.2%F 18 mm | 0 | – | 47.5 | – | 71.7 | |
| grSa+0.3%F 18 mm | 0 | – | 39.7 | – | 64.5 | |
| grSa+1.5%C | 0 | 31.5 | 36.1 | 65.5 | 61.2 | |
| 7 | – | 195.9 | – | 205.1 | ||
| 28 | – | 166.8 | – | 303.9 | ||
| grSa+1.5%C+0.3%F 18 mm | 0 | – | 77.5 | – | 154.5 | |
| 7 | – | 310.5 | – | 276.5 | ||
| 28 | – | 319.6 | – | 359.6 | ||
[i] C – cement addition, F – fibre addition