Figure 1:
Aggregate grading combination for surface course
Figure 2:
SBS modifier (left) and PEG modifier (right)
Figure 3:
Flowchart of the experimental work
Table 1:
Blend codes with modifiers content
| Blend code | Modifier content [%] | |
|---|---|---|
| SBS | PEG | |
| BA | 0 | 0 |
| S1 | 2 | 0 |
| S2 | 3 | 0 |
| S3 | 4 | 0 |
| P1 | 0 | 1.5 |
| P2 | 0 | 2.5 |
| P3 | 0 | 3.5 |
| SP1 | 2 | 1.5 |
| SP2 | 3 | 2.5 |
| SP3 | 4 | 3.5 |
Figure 4:
Some of prepared specimens for splitting test
Figure 5:
Wheel tracking test: (a) aggregates mixtures, (b) loose asphalt mixtures, (c) compactor device, (d) compacted slabs, (e) wheel tracking machine, (f) slabs after rutting test
Table 2:
Physical characteristics data for modified binders
| Blend ID | Property | ||
|---|---|---|---|
| Penetration [0.1 mm] | Softening point [°C] | Ductility [cm] | |
| BA | 44 | 52.0 | > 150 |
| S1 | 37 | 56.7 | 127 |
| S2 | 35 | 57.5 | 113 |
| S3 | 33 | 58.7 | 105 |
| P1 | 39 | 56.4 | > 150 |
| P2 | 37 | 57.2 | > 150 |
| P3 | 34 | 58.4 | > 150 |
| SP1 | 34 | 57.9 | 112 |
| SP2 | 31 | 59.1 | 107 |
| SP3 | 29 | 60.2 | 102 |
| Limits (Standard Specifications for Roads and Bridges, 2003) | Not limited | Not limited | 100 (minimum) |
Figure 6:
SEM images: (a) BA, (b) SBS, (c) PEG, (d) S2, (e) P2, and (f) SP2
Table 3:
Average splitting strength in dry and wet conditions
| Mixture type | Average splitting strength [kPa] | |
|---|---|---|
| Dry condition | Wet condition | |
| BA | 1189.6 | 982.3 |
| S1 | 1251.3 | 1052.5 |
| S2 | 1308.7 | 1123.9 |
| S3 | 1385.1 | 1205.5 |
| P1 | 1224.8 | 1038.5 |
| P2 | 1297.0 | 1135.1 |
| P3 | 1342.8 | 1198.1 |
| SP1 | 1388.3 | 1252.7 |
| SP2 | 1491.7 | 1363.6 |
| SP3 | 1588.0 | 1470.0 |
Figure 7:
TSR for unmodified and modified mixtures
Figure 8:
Outcomes of wheel tracking test