Viscosity Bitumen
Viscosity Grads
Viscosity Bitumen: Optimal Performance for Road Construction
Viscosity bitumen is a specialized type of bitumen classified based on its viscosity rather than penetration grade. It plays a crucial role in road construction and pavement applications, where maintaining specific flow characteristics is essential for durability and performance. The viscosity grading system ensures optimal workability across various temperature conditions, making it a preferred choice for infrastructure projects.
Common Viscosity Grades and Their Applications
VG-10: Ideal for spraying applications such as surface dressing and sealing.
VG-20: Best suited for moderate climates, commonly used for road paving in areas with mild temperature fluctuations.
VG-30: The most widely used grade in road construction, particularly in regions experiencing significant temperature variations.
VG-40: Designed for heavy-duty pavements and extreme weather conditions, ensuring superior strength and longevity.
Why Choose Viscosity Bitumen?
Viscosity bitumen offers better temperature stability, ensuring long-lasting road durability and enhanced performance. Its adaptability to different environmental conditions makes it a reliable solution for pavement engineering and infrastructure development.
Table 1-2: Technical specifications of pure bitumen’s in terms of viscosity at (C°)60 according to AASHTO-M226
Test | Viscosity degree | |||||
5/2 AC- | 5 AC- | 10 AC- | 20 AC- | 30AC- | 40AC- | |
Viscosity at (C°)60, in Poise | 250±50 | 100±500 | 200±1000 | 400±2000 | 600±3000 | 800±4000 |
Viscosity at (C°)135, min. | 125 | 175 | 250 | 300 | 350 | 400 |
Penetration rate at (C°)25, 100g, 5 seconds, Minimum | 220 | 140 | 80 | 60 | 50 | 40 |
Flash point, Cleveland open cup, (°C), Minimum | 163 | 177 | 219 | 232 | 232 | 23 |
Solubility in Trichloroethylene, % | 0/99 | 0/99 | 0/99 | 0/99 | 0/99 | 0/99 |
Test on the remaining thin layer of bitumen in the test: | ||||||
Heat loss, %, maximum | – | 0/1 | 5/0 | 5/0 | 5/0 | 5/0 |
Viscosity at (C°)60, Poise | 1000 | 2000 | 4000 | 8000 | 12000 | 16000 |
Bitumen elongation, cm, at (C°)25 at a speed of 5 cm/min, minimum | 100(1) | 100 | 75 | 50 | 40 | 25 |
Stain test (on a case-by-case or specification basis) with: | ||||||
Solvent naphtha | Negative result for all the above bitumen’s. | |||||
Naphtha-xylene solvent, percentage of xylene | Negative result for all the above bitumen’s. | |||||
Solvent naphtha xylene, percentage of xylene | Negative result for all the above bitumen’s. | |||||
- (1) If the elongation at 25 °C is less than 100 cm, it is acceptable provided that the elongation at 15.6 °C at a stretching speed of 5 cm/min is at least 100 cm.
Table 1-3: Technical specifications of pure bitumen’s in terms of viscosity at (C°)60 according to AASHTO-M226
Remaining results from the Ashto240T test method (1) | Viscosity grade | ||||
10AR- | 20AR- | 40AR- | 80AR- | 160AR- | |
Viscosity at (C°)60, Poise | 250±1000 | 500±2000 | 1000±4000 | 2000±8000 | 4000±16000 |
Viscosity at (C°)135, minimum cSt | 140 | 200 | 275 | 400 | 550 |
Penetration rate at 25, 100g, duration 5 seconds – minimum | 65 | 40 | 25 | 20 | 20 |
Percentage of penetration degree of primary bitumen at 25 – minimum | – | 40 | 45 | 50 | 52 |
Bitumen elongation at 25°C at a speed of 5 cm/min, cm, minimum | 100(2) | 100(2) | 75 | 75 | 75 |
Test on primary bitumen | |||||
Cleveland Open Cup Flash Point, oC, min. | 205 | 219 | 227 | 232 | 238 |
Solubility in trichloroethylene, % | 0/99 | 0/99 | 0/99 | 0/99 | 0/99 |
- 1) Ashto240T (Bitumen Thin Film Test) may be used, but Ashto240T should be used as a comparative method.
- (2) The bitumen elongation is less than 100, the material will remain. If the bitumen elongation at 15.6 oC is at least 100.
Table 1-4: A technical specification of pure bitumen’s in terms of viscosity at °C60 according to ASTM-D3381
Test | Viscosity degree | ||||
5/2AC- | 5AC- | 10AC- | 20AC- | 40AC- | |
Viscosity at 60°C, Poise | 250±50 | 500±100 | 1000±200 | 2000±800 | |
Viscosity at 135°C, cSt, min. | 80 | 110 | 150 | 210 | 300 |
Penetration rate at 25°C, 100g, 5 seconds, minimum | 200 | 120 | 70 | 40 | 20 |
Cleveland Open Cup Flash Point, oC, min. | 163 | 177 | 219 | 232 | 232 |
Solubility in Trichloroethylene, % | 0/99 | 0/99 | 0/99 | 0/99 | 0/99 |
Test on residual bitumen: | |||||
Viscosity at oC60, Poise, max. | 1250 | 2500 | 5000 | 10000 | 20000 |
Bitumen elongation at 25 oC at a speed of 5 cm/min, %, minimum | 100(1) | 100 | 50 | 20 | 10 |
- (1) If the elongation at 25 °C is less than 100 cm, it is acceptable provided that the elongation at 15.6 °C at a stretching speed of 5 cm/min is at least 100 cm.
Table 1-5: Technical specifications of pure bitumen’s in terms of viscosity at °C60 according to ASTM-D3381.
Test | Viscosity degree | |||||
5/2AC- | 5AC- | 10AC- | 20AC- | 30AC- | 40AC- | |
Viscosity at 60°C , in Poise | 250±50 | 500±100 | 1000±200 | 2000±400 | 3000±600 | 4000±800 |
Viscosity at 135°C, Centistokes, minimum | 125 | 175 | 250 | 300 | 350 | 400 |
Penetration rate at 25 °C, 100g, duration 5 seconds – minimum | 220 | 140 | 80 | 60 | 50 | 40 |
Cleveland Open Cup Flash Point °C-min | 163 | 177 | 219 | 232 | 232 | 232 |
Solubility in trichloroethylene – minimum – percent | 0/99 | 0/99 | 0/99 | 0/99 | 0/99 | 0/99 |
Testing on bitumen remaining from thin bitumen layer: | ||||||
Viscosity at 60°C, Poise max. | 1250 | 2500 | 5000 | 10000 | 15000 | 20000 |
Bitumen tensile strength at 25°C at a speed of 5 cm/min, cm, minimum | 100(1) | 100 | 75 | 50 | 20 | 10 |
- (1) If the elongation at 25 °C is less than 100 cm, it is acceptable provided that the elongation at 15.6 °C at a stretching speed of 5 cm/min is at least 100 cm
Table 1-6: Technical specifications of pure bitumen’s in terms of viscosity at °C 60 according to ASTM-D3381
Experiments on thin bitumen layer residue (1) | Viscosity degree | ||||
1000AR- | 2000AR- | 4000AR- | 8000AR- | 16000AR- | |
Viscosity at °C 60, in Poise | 1000±250 | 2000±500 | 4000±1000 | 8000±2000 | 16000±4000 |
Viscosity at 135°C, cSt, min. | 140 | 200 | 275 | 400 | 550 |
Penetration rate at 25°C, 100g, duration 5 seconds, minimum | 65 | 40 | 25 | 20 | 20 |
Percentage of penetration degree of primary bitumen at 25 °C, minimum | – | 40 | 45 | 50 | 52 |
Bitumen elongation at °C at a speed of 5 cm/min, cm, minimum | 100(1) | 100(2) | 75 | 75 | 75 |
Testing on bitumen remaining from a thin Bitumen layer: | |||||
Cleveland Open Cup Flash Point, °C, min. | 205 | 219 | 227 | 232 | 238 |
Solubility in trichloroethylene, minimum, % | 0/99 | 0/99 | 0/99 | 0/99 | 0/99 |
- (1) Thin bitumen film may be used in the test. However, the thin bitumen film test should be used as a comparative method.
- (2) It is acceptable if the elongation at 25 °C is less than 100 cm. Provided that the elongation at 15.6 °C at a stretching speed of 5 cm/min is at least 100 cm.