is Bitumen that is dissolved in a solvent. Typical solvents include Naptha, gasoline and kerosene, white spirit etc. The type of solvent controls the curing time while the amount determines the viscosity of the Cutback Bitumen.
The advantage Cutbacks have over Emulsions is a much higher residual Bitumen percent, typically over 80% compares with over 40-65% for Bitumen emulsions. The result is more Bitumen 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.
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
Application
Cutback bitumen’s suitable for primer sealing can also be used in the manufacture ofpre-mix asphalt, which is used in patch repairs.Cutback bitumen’s are used extensively in sprayed sealing applications, particularly in cooler weather where theyprovide improved initial stone retention due to their lower viscosity. Typically, a single application of the appropriate cutback bitumen is sprayed onto the primed pavement ontowhich aggregate is laid.
SPECIFICATION FOR MEDIUM CURING CUT BACK BITUMEN
| PROPERTY | RANGE | STANDARD | ||
|---|---|---|---|---|
| BITUMEN MC 30 | BITUMEN MC 70 | BITUMEN MC 3000 | ASTM / AASHTO | |
| Kinematic 1 viscosity @ 60°C,e St | 30/60 | 70/140 | 3000/50000 | ASTM D1270 /AASHTOT201 |
| Flash Point ( Tag Open- Cup), ° C | 38 | 38 | 36 | ASTM D1310 / AASHTO T79 |
| Distillation Test°@360 °C | – | – | – | – |
| Residue from distillation to 360 °C, Percent volume by different | 50% | 55% | 80% | ASTM D402 / AASHTO T55 |
| Test on residue from distillation | – | – | – | – |
| Viscosity at 60° C | 300-1200 | 300-1200 | 300-1200 | ASTM D2170 /AASHTOT201 |
| Penetration at 25 ° C, 100g, 5 Sec | 120/150 | 120/150 | 120/150 | ASTM D5 / AASHTO T49 |
| Ductility 3 at 25 ° C | >100 | >100 | >100 | ASTM D113 / AASHTO T51 |
| Solubility in trichloroethylene | 99.00% | 99.00% | 99.00% | ASTM D2402 / AAHTO T44 |
| Water, Percent Volume | 0.20% | 0.20% | 0.20% | ASTM D95 / AASHTO T55 |
SPECIFICATION FOR RAPID CURING CUTBACK BITUMEN
| PROPERTY | GRADE | STANDARD | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| RC-30 | RC-70 | RC-250 | RC-800 | RC-3000 | METHOD | ||||||
| Min | Max | Min | Max | Min | Max | Min | Max | Min | Max | ||
| Flash point(open tag)deg C | – | – | – | – | – | 27 | – | 27 | – | 27 | ASTM D3143 |
| Kinematic Viscosity at 60decC (mm 2/3) | 30 | 60 | 70 | 140 | 250 | 500 | 800 | 1600 | 3000 | 6000 | ASTM D2170 |
| Distillate to 360 dec C | ASTM 402 | ||||||||||
| to 190 dec C | 15 | – | 10 | – | – | – | – | – | – | – | |
| to 225 dec C | 55 | – | 50 | – | 35 | – | 15 | – | – | – | |
| to 260 dec C | 75 | – | 70 | – | 60 | – | 45 | – | 25 | – | |
| to 315 dec C | 90 | – | 85 | – | 80 | – | 75 | – | 70 | – | |
| Residue from Distillation | 50 | – | 55 | – | 65 | – | 75 | – | 80 | – | – |
| to360dec C, Volume % by diffrence test on residue from distillation | – | – | – | – | – | – | – | – | – | – | – |
| Penetration @25deg C,100g 5s, (0.1 mm) | 80 | 120 | 80 | 120 | 80 | 120 | 80 | 120 | 80 | 120 | ASTM D5 |
| Ductility@25decC | 100 | – | 100 | – | 100 | – | 100 | – | 100 | – | ASTM D113 |
| Solubility in trichloroethylene | 99 | – | 99 | – | 99 | – | 99 | – | 99 | – | ASTM D2042 |
| Water by volume | – | 0.2 | – | 0.2 | – | 0.2 | – | 0.2 | – | 0.2 | ASTM D95 |
Packing
Standard Seaworthy Exportable Packing in200 Kg Reconditioned Drums
Palletizing is required for Cutback Bitumen & Emulsions -200kg drums shall be secured as 4 drums per pallet
Steel Drum Sizes
Drum Size 200 kg Drum
Height 980mm
Diameter 520 – 550mm
Thickness 0.6 – 0.8mm
| Net Packing | Weight per 20 Foot Container | ||
|---|---|---|---|
| 200 Kg | In Metric Tonnes | Per Drum | No of Drums |
| Net Weight-Palletized | 16.00 Mt (+/- 3%) | 200kgs (+/- 3kgs) | 80 |
| Gross Weight-Palletized | 17.40 Mt (+/- 3%) | 215kgs (+/- 3kgs) | 20 |