Bitumen MC 70

General Information of Cutback Bitumen MC-70

ATDM manufactures cutback bitumen MC-70, which is a medium-curing (MC) cut-back asphalt. It consists of high-quality penetration grade asphalt cement mixed with a medium-volatility diluent or cutter. This diluent temporarily reduces the viscosity of the asphalt, making it easier to handle and apply. Once applied, the diluent evaporates, leaving the asphalt cement to perform its intended function. As a result, you can use this cutback bitumen for roofing applications, such as waterproofing membranes and as an adhesive to bond chippings to flat roofs, effectively minimizing weathering from the sun.

Furthermore, we produce cutback bitumen MC-70 by dissolving bitumen in solvents like kerosene. In many regions, kerosene and other petroleum-derived products serve as cutback agents, which reduce the viscosity of bitumen. Consequently, this reduction aids in applying seal coats to road pavements, where the softened bitumen wets the chips more efficiently. Moreover, after application, the cutback agent evaporates, becoming negligible within a few months. However, if a significant amount remains in the coat, it could lead to undesirable softening effects over time.

About Cutback Bitumen MC-70

ATDM’s MC-70 cutback bitumen complies with ASTM D2028-97 (reapproved in 2004) for medium-curing cutback petroleum asphalts, which are essential in the construction and treatment of pavements. This product is commonly used in spraying and mixing applications. Bitumen, in this case, is a penetration grade, blended with solvents like kerosene, white spirit, gasoline, or naphtha, all of which control the curing time. In addition, we manufacture our petroleum-grade bitumen through fractional or vacuum distillation of crude oil. Notably, this unique temperature-viscosity relationship helps determine key performance parameters such as adhesion, rheology, durability, and application temperatures.

Bitumen MC-70: Liquid Solvent Base

For many years, MC-70 bitumen products have been used effectively for road surface maintenance and repair, particularly for road surfaces. This product is commonly referred to as “asphalt medium curing” or “tack oil.” Although effective for bonding, MC-70 has some limitations. Specifically, when repairing potholes or filling cracks in existing asphalt surfaces, it works primarily as a bonding agent, not forming a homogeneous mixture of new and old asphalt.

How to Use MC-70 in Road Applications

For the best results, weather and climate conditions should be ideal when applying MC-70. Therefore, avoid using it in cold or wet weather, or on wet surfaces. Moreover, the application process requires both a skilled highway crew and specialized equipment. You must preheat the bitumen to 250°F for 2-3 hours before applying it. Once heated, apply the bitumen, then roll or tamp the overlaying asphalt into place to form a smooth surface.

MC-70 in Airports, Highways, and Helipads

Alternatively, you can apply MC-70 as a top dressing to create a flexible, tough, and abrasion-resistant surface. This treatment increases the compressive and tensile strengths of the base course, making it ideal for moderate airport traffic, highways, or helicopter landing zones. Additionally, you can customize the top dressing with colors like green or black, depending on aesthetic or functional needs.

Uses of Cutback Bitumen MC-70

Cutback agents, like kerosene, are used to reduce the viscosity of bitumen, especially when applied as a primer on road pavements or aggregate base courses. Furthermore, you can adjust the concentration of the cutback agent based on local conditions and requirements. Notably, MC-70 is ideal for prime coat applications and cold applications due to its ease of use and the fact that it doesn’t require thinning or heating. Additionally, it effectively waterproofs surfaces, seals capillary voids, and bonds loose mineral particles.

Some common uses include penetrating prime coats and producing patching or stockpile mixtures. When mixed with aggregates, MC-70 often contains an adhesion agent, which helps coat the aggregate surface effectively.

Packing of Cutback Bitumen MC-70

ATDM delivers MC-70 in bulk tanker shipments or in new, thick steel drums placed on pallets. This secure packaging prevents leakage and ensures the product’s quality during transport. As a result, customers can rely on safe and secure delivery.

Safety of Cutback Bitumen MC-70

Always refer to the Safety Data Sheets (SDS) before using MC-70. It is crucial to store, transport, and use the product at the lowest possible temperature. Additionally, during application, eliminate all potential ignition sources. To ensure safety, avoid inhaling vapors or coming into contact with the skin. Always wear appropriate personal protective equipment (PPE), including heat-resistant gear, especially when applying the product hot. Finally, make sure that neither the product nor its washings enter stormwater or sewer systems.

Analysis and Specifications of Cutback Bitumen MC-70

ATDM’s MC-70 cutback bitumen meets the following specifications:

– Kinematic Viscosity at 60°C: 70-140 cST (ASTM D2170)
– Flash Point (Tag Open Cup): Minimum 38°C (ASTM D3143)

Distillation Test (ASTM D402):
– Distillate Volume Percent of Total:
– To 437°F (225°C): Minimum 20%
– To 500°F (260°C): Minimum 70%
– To 600°F (316°C): Minimum 93%
– Residue from Distillation to 680°F (360°C): Minimum 55%

Test on Residue from Distillation:
– Viscosity at 140°F (60°C): 30-120 cST (ASTM D2170)
– Penetration at 77°F (25°C), 100g for 5 Seconds: 120-300 mm (ASTM D5)
– Ductility at 77°F (25°C), 5 cm/min: Minimum 100 cm (ASTM D113)
– Solubility in Trichloroethylene: Minimum 99% (ASTM D2042)
– Water Content: Maximum 0.2% (ASTM D95)

Conclusion

ATDM’s cutback bitumen MC-70 provides an effective solution for a wide range of road construction, repair, and maintenance applications. Thanks to its ability to reduce viscosity, it ensures ease of application, especially for prime coats and top dressing. With its strong adhesion properties, MC-70 guarantees lasting performance, whether for road pavements, highways, or airports.