Asphalt Viscosity Test

Viscosity

Viscosity testing of asphalt is critical in the determination of mixing and compaction. Asphalt binder viscosity measures a fluid’s resistance to flow and is typically measured to replicate the HMA pavement surface temperature during summer in the USA (60°C or 140°F). Liquid resistance in flowing is viscosity by definition. So, the fluid has higher resistance when the viscosity is higher. The chemical composition and structure of the bitumen are both factors that define the viscosity.

An improved asphalt grading system was developed in the 1960s which replaced the penetration test as a more accurate asphalt binder evaluation. AC grading is done on original binder samples and AR grading is done on aged residue samples. The AR grading system better simulates the binder properties after HMA manufacturing and therefore better represents how the binder holds up in actual HMA pavements.

Viscosity grade bitumens, usually used for paving, are ideal for the application of road construction and resulting asphalt pavements with superior properties.

Humboldt’s viscosity testing equipment was designed to provide quality control assurance in asphalt binder testing standards.

Constant Temperature Baths – Aid in precise viscosity determinations with glass capillary viscometers. Digital Vacuum Pressure Regulators (DVR) display the amount of vacuum or other units of measurement selected.

Viscometers – The Zeitfuchs® Cross-Arm Viscometer determine kinematic viscosity of liquid asphalts. The Vacuum Viscometer was designed for measuring highly-viscous materials.

Saybolt Viscosity Baths – Designed for Saybolt universal and furol viscosity testing. Meets all ASTM and AASHTO standards for precise temperature control. Models are available for use with one to four Automatic Saybolt Viscosity Timing Sensors.