Cutback Bitumen ( Liquid Bitumen ) 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.

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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 sealingapplications, 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

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

 

DIFFERENT SYSTEMS OF ROAD CONSTRUCTION &ROAD MAINTENANCE 

SYSTEMS DESCRIPTION & USES RECOMMENDED PRODUCT
Surface Dressing An application of binder on the road surface by a bitumen distributor followed by a covering of aggregates/chippings spread by a hopper gritter. Can be a single or double layer surface dressing Emulsion : RS-3K Cut Back : MC -3000
Prime Coating An application of binder on a granular base to prepare for an asphalt surfacing .Normally a slow setting emulsion or cutback is used for better penetration purposes to seal off the road base. The rate of application can vary from 0.4-1.4 liter/m2 Emulsion: SS-IK Cut back : MC-30 MC -70
Tack Coating A very light application of binder –hand or machine sprayed –to ensure bonding between the existing layer and the new overlay. The rate of application is normally between 0.25-0.7 liter/m2,depending on the surface being sprayed Emulsion:K1-40 : RS-1K : RS-2K
Semi –Grouting /Penetration Macadam An application of hot binder on a compacted layer of coarse aggregate Emulsion : RS-3K : MC-3000 Other : Bitumen
Slurry Sealing A maintenance technique where specially tailored emulsion ,aggregates ,water, and /or mineral filler is mixed in an on-site distributor and spread on an existing road surface at a thickness of 3-6 mm .It is both a preventive and corrective maintenance method for sealing of surface cracks, water –proofing asphalt surfaces and stopping oxidation Emulsion : ALFA/SS
Fog Sealing /Mist Spraying It is similar to tack coating in that is a very light application of diluted emulsion for renewal/rejuvenation of old asphalt surfaces. The emulsion is usually diluted to a concentration of about 25-30% binder and applied at a rate of 0.3-0.8 liter/m2 Emulsion : K1-40 : SS-1K : ALFA
Dust Binding A light application of 0.5-2.0 liter/m2 using diluted bitumen emulsion for dust control on unpaved roads Emulsion : K1-40 : SS-1K
Cutback Bitumen (Medium & Rapid)
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