Bitumen is graded based on absolute viscosity at 60 ºC or kinematic viscosity at 135 ºC. The SI physical unit of dynamic viscosity is Poise and kinematic viscosity is expressed in Centi Stokes. Pure bitumen has been graded based on AASHTO-M226 and ASTM-D3381 standards. Tables 1-1 to 1-6 indicate tests and criteria.
Viscosity Grade Bitumen which is produced during the process of oxidation of vacuum bottom in distillation tower and is categorized based on absolute viscosity at 60 ºC or kinematic viscosity at 135 ºC. There are four grades VG-10, VG-20, VG-30 & VG-40. The main common usage of VG is in road construction, water proofing, building construction industries and also in cutback bitumen production.
- Viscosity Grade 40-Viscosity Grade
- Viscosity Grade 30-Viscosity Grade
- Viscosity Grade 20-Viscosity Grade
- Viscosity Grade 10-Viscosity Grade