Overview
Viscosity-grade bitumen is classified by viscosity instead of penetration. The grading keeps the binder workable across temperatures and gives better temperature stability, which helps roads last.
Common grades
- VG-10: spraying work such as surface dressing and sealing.
- VG-20: paving in moderate climates with mild temperature variation.
- VG-30: road construction where temperature differences are large.
- VG-40: heavy-duty pavements and extreme weather.
Technical data sheet
Viscosity grades at 60 °C, AC series (AASHTO M 226)
| Test | AC-2.5 | AC-5 | AC-10 | AC-20 | AC-30 | AC-40 |
|---|---|---|---|---|---|---|
| Viscosity at 60 °C, poise | 250±50 | 500±100 | 1000±200 | 2000±400 | 3000±600 | 4000±800 |
| Viscosity at 135 °C, min (cSt) | 125 | 175 | 250 | 300 | 350 | 400 |
| Penetration 25 °C, 100 g, 5 s, min | 220 | 140 | 80 | 60 | 50 | 40 |
| Flash point, Cleveland open cup, min (°C) | 163 | 177 | 219 | 232 | 232 | 232 |
| Solubility in trichloroethylene, min (%) | 99.0 | 99.0 | 99.0 | 99.0 | 99.0 | 99.0 |
| Thin-film residue: heat loss, max (%) | — | 1.0 | 0.5 | 0.5 | 0.5 | 0.5 |
| Residue viscosity at 60 °C (poise) | 1000 | 2000 | 4000 | 8000 | 12000 | 16000 |
| Residue ductility 25 °C, 5 cm/min, min (cm) | 100 | 100 | 75 | 50 | 40 | 25 |
| Stain test (solvent naphtha, naphtha-xylene) | Negative | Negative | Negative | Negative | Negative | Negative |
Where ductility at 25 °C is below 100 cm, the grade is acceptable if ductility at 15.6 °C and 5 cm/min is at least 100 cm.
Aged-residue grades, AR series (AASHTO M 226 / ASTM D3381)
| Test on thin-film residue | AR-10 | AR-20 | AR-40 | AR-80 | AR-160 |
|---|---|---|---|---|---|
| Viscosity at 60 °C, poise | 1000±250 | 2000±500 | 4000±1000 | 8000±2000 | 16000±4000 |
| Viscosity at 135 °C, min (cSt) | 140 | 200 | 275 | 400 | 550 |
| Penetration 25 °C, 100 g, 5 s, min | 65 | 40 | 25 | 20 | 20 |
| Penetration vs. original bitumen, min (%) | — | 40 | 45 | 50 | 52 |
| Ductility 25 °C, 5 cm/min, min (cm) | 100 | 100 | 75 | 75 | 75 |
| Flash point, Cleveland open cup, min (°C) | 205 | 219 | 227 | 232 | 238 |
| Solubility in trichloroethylene, min (%) | 99.0 | 99.0 | 99.0 | 99.0 | 99.0 |
Where ductility at 25 °C is below 100 cm, it is acceptable if ductility at 15.6 °C is at least 100 cm.
Viscosity grades, AC series, 5 grades (ASTM D3381)
| Test | AC-2.5 | AC-5 | AC-10 | AC-20 | AC-40 |
|---|---|---|---|---|---|
| Viscosity at 60 °C, poise | 250±50 | 500±100 | 1000±200 | 2000±400 | 4000±800 |
| Viscosity at 135 °C, min (cSt) | 80 | 110 | 150 | 210 | 300 |
| Penetration 25 °C, 100 g, 5 s, min | 200 | 120 | 70 | 40 | 20 |
| Flash point, Cleveland open cup, min (°C) | 163 | 177 | 219 | 232 | 232 |
| Solubility in trichloroethylene, min (%) | 99.0 | 99.0 | 99.0 | 99.0 | 99.0 |
| Residue viscosity at 60 °C, max (poise) | 1250 | 2500 | 5000 | 10000 | 20000 |
| Residue ductility 25 °C, 5 cm/min, min (cm) | 100 | 100 | 50 | 20 | 10 |
Where ductility at 25 °C is below 100 cm, it is acceptable if ductility at 15.6 °C is at least 100 cm.
Viscosity grades, AC series, 6 grades (ASTM D3381)
| Test | AC-2.5 | AC-5 | AC-10 | AC-20 | AC-30 | AC-40 |
|---|---|---|---|---|---|---|
| Viscosity at 60 °C, poise | 250±50 | 500±100 | 1000±200 | 2000±400 | 3000±600 | 4000±800 |
| Viscosity at 135 °C, min (cSt) | 125 | 175 | 250 | 300 | 350 | 400 |
| Penetration 25 °C, 100 g, 5 s, min | 220 | 140 | 80 | 60 | 50 | 40 |
| Flash point, Cleveland open cup, min (°C) | 163 | 177 | 219 | 232 | 232 | 232 |
| Solubility in trichloroethylene, min (%) | 99.0 | 99.0 | 99.0 | 99.0 | 99.0 | 99.0 |
| Residue viscosity at 60 °C, max (poise) | 1250 | 2500 | 5000 | 10000 | 15000 | 20000 |
| Residue ductility 25 °C, 5 cm/min, min (cm) | 100 | 100 | 75 | 50 | 20 | 10 |
Where ductility at 25 °C is below 100 cm, it is acceptable if ductility at 15.6 °C is at least 100 cm.