Viscosity test by capillary viscometers

The kinematic as well as the dynamic viscosity of the bituminous binders can be measured by capillary viscometers. Kinematic viscosity is measured with capillary viscometers in which the flow is caused by gravitational force. Hence, kinematic viscosity is a measure of a liquid s resistance to flow under gravity. The dynamic viscosity is measured with vacuum viscometers, where the flow is assisted (drawn up) by vacuum pressure (40 kPa). 

The capillary viscometers determine the kinematic viscosity of bituminous binders at 135°C or at 60°C (soft bitumen) with a range of 6 to 300,000 mmVs (CEN EN 12595 2007) or up to 100,000 mmVs (ASTM 2710). 

By performing the test, the time for a fixed volume of the liquid to flow through the capillary of a calibrated glass capillary viscometer under an accurately reproducible head and at 

A detailed description of the test for the determination of the kinematic viscosity by capillary viscometers is given in CEN EN 12595 (2007), ASTM D 2170 (2010) or AASHTO T 201 (2010). 

The vacuum capillary viscometers determine the dynamic viscosity of bituminous binders at 60°C with a range of 0.0036 to more than 580,000 Pa-s (CEN EN 12596 2007) or up to 20,000 Pa-s (ASTM D 2171 2010). Dynamic viscosity is a measure of the resistance to the flow of a liquid and is commonly called the viscosity of the liquid. 

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