Viscosity Grade Bitumen
Viscosity Grade (VG) bitumen is a standard grade of bitumen used for road construction and asphalt production with superior properties. Due to the viscoelastic behavior of this group of bitumen, stronger and more flexible connections will be made between the bitumen and the building materials, depending on the mixing speed of the materials. Showing the characteristics of bitumen, viscosity is more than the other two common properties, i.e. softening point and penetration. Therefore, viscosity-based classification (degree of fluidity) is presented separately, and codes AC-2.5 to AC-40 are employed to classify the properties of bitumen. Different types of bitumen are classified according to their absolute viscosity at 60 °C in poise and/or kinematic viscosity at 135 °C in centistokes.
These types of bitumen show thermoplastic properties that soften the bitumen at higher temperatures and become harder at lower temperatures. This temperature-viscosity relationship is uniquely important in determining functional parameters such as adhesion, rheology, durability, and the temperature application of bitumen. Regarding the viscosity grade bitumen, there is more emphasis on the ductility of the product.
Viscosity Grade Bitumen: VG-10 Bitumen
This type of bitumen is utilized to stain cracked surfaces and spray various applications. It can be an alternative for the penetration grade bitumen 80-100 in very cold areas. This category of bitumen is also employed to produce emulsion and modified bitumen.
Viscosity Grade Bitumen: VG-20 Bitumen
This type of bitumen is mostly used in cold climates and highlands.
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Viscosity Grade Bitumen: VG-30 Bitumen
This category of bitumen is used primarily for the surfaces that undergo very heavy loads and need to withstand high traffic loads. It can be used instead of bitumen grade 60-70.
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Viscosity Grade Bitumen- VG-40 Bitumen
This category of bitumen is used instead of penetration grade bitumen 40-30 in areas with high traffic loads and pressure such as intersections, near road tolls, and parking lots of heavy vehicles. Due to the high viscosity of this type of bitumen, it can resolve the problems of surface tension, resistance, higher temperatures, and heavy traffic loads.