Medium curing Cutback Bitumen is a process used to create soluble bitumen in asphalt cutbacks, which are classified into three groups based on their evaporation speed. A mixture of oil solvents, including kerosene, is used to transform bitumen into soluble bitumen, leaving behind a cohesion and penetration layer. This process is known as Medium Curing Cutback Bitumen (MC250), which is used in the asphalt industry for pavement and cold asphalt. The degree of liquidity depends on the proportion of solvent to asphalt cement, with some grades being more fluid at ordinary temperatures and others more viscous. Medium setting grades are designed for mixing with aggregates, allowing them to remain workable for extended periods and lend themselves to cold mix stockpiles.

Description of Medium Curing Cutback Bitumen

Petroleum solvents are used to fluidize asphalt cement in asphalt cutbacks. Distillate, diluents, or cutter stock are the solvents. Solvents used to make cutback asphalt will evaporate quickly if they are highly volatile. Solvents with a lower volatility will evaporate at a slower pace. Less volatile solvents can be used in constructing cutback asphalt to slow down the rate of evaporation, as the use of highly volatile substances as solvents can cause rapid evaporation and escape Cutback asphalts, known as rapid curing (RC), medium curing (MC), and slow-curing (SC), are classified into three groups based on their evaporation speed.

A mixture of various oil solvents, including kerosene, is used in the process of transforming bitumen into soluble bitumen. The bitumen layer is left behind to provide cohesion, penetration, and form a sealing layer, while the evaporated oil solvent is eliminated. This is how Medium Curing Cutback Bitumen is created. A well-known type of it, called MC250 or liquid bitumen, is used in the asphalt industry for pavement, which is cohesive between two layers of tack coat asphalt and can also be used for cold asphalt.

(Road mix) Subbase (continuous-primer between asphalt and soil layers) was previously used in Iran. Kerosene available in the Medium Curing Cutback Bitumen 250 facilitates bitumen remediation and penetration in infrastructure applications (priming), but compared to various types of water-based emulsions, the kerosene has reduced environmental hazards, price and use. When heating costs, the discharge time will still increase.

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.

The medium setting grades are designed for mixing with aggregates. Because these grades do not break immediately upon contact with aggregate, mixes using them can remain workable for extended periods of time and lend themselves to cold mix stockpiles.

Application of Medium Curing Cutback Bitumen

The medium setting grades are designed for mixing with aggregates. Because these grades do not break immediately upon contact with aggregate, mixes using them can remain workable for extended periods of time and lend themselves to cold mix stockpiles.

A cutback bitumen medium curing Medium Curing Cutback Bitumen is simply a combination of asphalt cement and petroleum solvent. Like emulsions, cutbacks are used because they reduce asphalt viscosity for lower temperature uses (tack coats, fog seals, slurry seals, stabilization material).

Similar to emulsified asphalts, after a cutback asphalt is applied the petroleum solvent evaporates leaving behind asphalt cement residue on the surface to which it was applied. Cutback asphalt is said to “cure” as the petroleum solvent evaporates away. The use of cutback asphalts is decreasing because of environmental regulations.

In short, the applications are as follows:

• Surface Dressing: Similar to RC, MC can be used to bind aggregates to the road surface. However, its slower curing time allows for better adhesion and durability.
• Prime Coats: Preparing the base course for subsequent asphalt layers. MC provides good adhesion and penetration.
• Tack Coats: Ensures proper bonding between asphalt layers. MC offers a balance between quick setting and strong adhesion.
• Cold Mix Asphalt: Medium Curing Cutback Bitumen can be used as a binder in cold mix asphalt production due to its moderate curing time.
• Fog Seals: To seal small cracks and restore surface texture. Medium Curing Cutback Bitumen provides a longer-lasting seal compared to RC.

Advantages of Medium Curing Cutback Bitumen

Medium Curing Cutback Bitumen (MC) offers a combination of benefits that make it a popular choice in road construction:

• Versatility: Suitable for a wide range of climatic conditions and applications.
• Balanced curing time: Provides a good balance between rapid and slow curing, allowing for optimal adhesion and durability.
• Improved adhesion: Offers better adhesion compared to RC cutback bitumen, resulting in a stronger bond between materials.
• Durability: Generally more durable than RC cutback bitumen, especially in moderate to cold climates.
• Workability: Easier to handle and apply than Slow Curing (SC) cutback bitumen.
• Cost-effective: Provides a good balance of performance and cost.