Cut Back Bitumen
Cut Back Bitumen
The advantage cutbacks have over emulsions is a much higher residual Bitumen percent, typically over 80 percent. This compares with just over 65 percent for Bitumen emulsions. The result is more Bitumen cement left on the roadway after curing, for the same volume of binder applied.
Cutback Classification
Cutbacks are divided into two classifications, Rapid-Curing (RC) and Medium-Curing (MC)
depending on the solvent used. They are further defined by a number which indicates the minimum kinematic viscosity (fluidity) of the cutback. The lower the number, the more fluid the cutback is.
Grades & Properties
| Grade | Curing Speed | Viscosity | Penetration of Residue |
| MC 30 | Medium | 30-60 | 120- 150 |
| MC 70 | Medium | 70-140 | 120 -150 |
| MC 250 | Medium | 250- 500 | 120 -150 |
| MC 800 | Medium | 800- 1600 | 120- 150 |
| MC 3000 | Medium | 3000- 6000 | 120- 150 |
| RC 70 | Rapid | 70-140 | 80- 120 |
| RC 250 | Rapid | 250-500 | 80- 120 |
| RC 800 | Rapid | 800- 1600 | 80- 120 |
| RC 3000 | Rapid | 3000- 6000 | 80- 120 |
* Kinematic Viscosity at 140 deg F ( 60 deg C), in Centistokes , Penetration of Residue at 77 deg F (25 deg C) , 100 grams, 5 seconds.
Detailed Specifications
Medium Curing Cut Back Bitumen MC30
Properties Range Standard
Kinemalic 1 viscosity at 60°C, eSt 30 /60 ASTM D2170
Flash Point (Tag Open-Cup),°C 38 / - ASTM D1310
Distillate test :
Distillate, percent by Volume of total Distillate to 360°C
To 190°C - / 15 ASTM D402
To 225°C 20 / 60 ASTM D402
To 260°C 50 / 90 ASTM D402
To 316°C 80 / 100 ASTM D402
Residue from distillation to 360°C, percent volume by different
Test on residue from distillation 50 / -
Penetration at 25°C,100g, 5 sec.
Ductility 3 at 25°C, cm 120 / 250 ASTM D402 / ASTM D5
Solubility in trichloroethylene, 100 / - ASTM D402 / ASTM D113
Water, percent volume 99.0 / - ASTM D402 / ASTM D2024
Water, percent volume - / 0.2 ASTM D95
Medium Curing Cut Back Bitumen MC70
Properties Range Standard
Kinemalic 1 viscosity at 60°C, eSt 70 /140 ASTM D2170
Flash Point (Tag Open-Cup),°C 38 / - ASTM D1310
Distillate test :
Distillate, percent by Volume of total Distillate to 360°C
To 190°C - / 10 ASTM D402
To 225°C 20 / 55 ASTM D402
To 260°C 40 / 80 ASTM D402
To 316°C 75 / 95 ASTM D402
Residue from distillation to 360°C, percent volume by different
Test on residue from distillation 55 / -
Penetration at 25°C,100g, 5 sec.
Ductility 3 at 25°C, cm 120 / 250 ASTM D402 / ASTM D5
Solubility in trichloroethylene, 100 / - ASTM D402 / ASTM D113
Water, percent volume 99.0 / - ASTM D402 / ASTM D2024
Water, percent volume - / 0.2 ASTM D95
Medium Curing Cutback MC3000
Properties Min Max
Kinematic viscosity at 600C (140 0F), centistrokes, 3000 6000
Flash point (Tag. Open Cup), [0C (0F)] 66(150) …
Water percent … 0.2
Distillation test:
Distillate percentage by volume of total distillates to 260 0C (500 0F) 0 15
Distillate percentage by volume of total distillates to 316 0C (600 0F) 15 75
Residue from distillation to 360 0C (680 0F) percent volume by difference 80 …
Test on residue from distillation:
Viscosity at 600C, (1400F), P or 300 1200
Penetration, 100g, 5sec, at 250C (770F), [dmm] 120 250
Ductility, 5cm/min, at 250C (770F), cm or 100 …
Ductility at 15.50C (600F), cm (See “Note 1”) 100 …
Solubility in Trichloroethylene, percent by weight, [%] 99 …
Spot test: (see ‘’Note’’)
Standard naphtha Negative Negative
Naphtha-xylene solvent, percent xylene Negative Negative
Heptane-xylene solvent, percent xylene Negative Negative
Sampling and Testing Standards for Cut Back Bitumen
Type o f T e s t Standards
AASHTO ASTM
Sampling T40 D140
Kinematic Viscosity T201 D2170
Flash point T79 D1310
Water T55 D95
Distillation T78 D402
Penetration T49 D5
Ductility T51 D113
Solubility in trichloroethylene T44 D2042
Spot test T102
