Slow Curing (SC)
Asphalt cutbacks use petroleum solvents for dissolving asphalt cement. The solvents are variously called distillate, diluents or cutter stock. If the solvent used in making the cutback asphalt is highly volatile, it will quickly escape by evaporation. Solvents of lower volatility evaporate more slowly. On the basis of the relative speed of evaporation, cutback asphalts are divided into three types:
- rapid curing (RC)
- medium curing (MC)
- slow curing (SC)
Slow curing (SC):
asphalt cement and oils of low volatility generally in the heavy distillate range (SC-70, 250, 800, 3000). The degree of liquidity developed in each case depends principally on the proportion of solvent to asphalt cement. To a minor degree, the liquidity of the cutback may be affected by the hardness of the base asphalt from which the cutback is made. The degree of fluidity results in several grades of cutback asphalt—some quite fluid at ordinary temperatures and others somewhat more viscous. The more viscous grades may require a small amount of heating to make them fluid enough for construction operations. Slow curing (SC) cutback asphalts are often called road oils and are used primarily in road-mixing and dust-laying applications.
This term originated in earlier days when asphalt residual oil was used to give roads a low-cost, all-weather surface.
SC cutback asphalts are also used for stockpile patching mixes, plant-mixed with graded aggregates and occasionally for priming.
Application of Cutback Bitumen SC 800:
Cutback bitumen SC 800 consist of initial incorporation of asphalt into the surface of non-asphalt based course preparatory to any superimposed treatment of construction.
In addition cutback asphalt SC 800 applying to waterproofing of surfaces, plug capillary voids, coat and bond loose mineral particles.
Cutback agents are used to lower the viscosity of bitumen when it is applied as a primer to the surface of a road pavement aggregate base course or substrate. Furthermore kerosene is used as a bitumen cutback agent at different concentrations according to local conditions and requirements.
Cutback bitumen is ideal for prime coat and cold applied because of easy uses. Also its no need to thinning and heating.
Packing of cutback bitumen SC 800:
Packing of cutback bitumen SC 800 is in new thick steel drum on pallet to prevent any leak inside of container also bulk in bitutainer and tanker.
Data sheet of SC 800:
| Properties | Min | Max | Test Method |
| Kinemalic 1 viscosity at 60°C, ESt | 800 | 1600 | ASTM D2170 |
| Flash Point (Tag Open-Cup),°C | 90 | - | ASTM D1310 |
| Distillate test 2 : | |||
| Distillate, percent by Volume of total 360°C | |||
| To 190°C | - | - | ASTM D402 |
| To 225°C | - | - | ASTM D402 |
| To 260°C | - | - | ASTM D402 |
| To 316°C | 2 | 12 | ASTM D402 |
| Residue from distillation to 60°C: 2000 16000 | |||
| Test on residue from distillation Penetration at | 70 | - | |
| 25°C,100 g, 5 sec. | |||
| Ductility 3 at 25°C, cm | 100 | - | ASTM D402 / ASTM D113 |
| Solubility in trichloroethylene, percent mass | 100 | - | ASTM D402 / ASTM D2024 |
| Water, percent volume | - | 0.2 | ASTM D95 |
