bitumen viscosity test
bitumen viscosity test
A metal cup is filled to a mark with cutback bitumen and brought to 40 ± 0.1°C for the required time. The cup has a ten millimeter orifice in its base which is covered by a smooth ball. When the temperature has equilibrated the ball is lifted and the sample allowed to flow through the orifice. The flow is timed for 50 cm3 of sample and the result is the viscosity in seconds, see photograph 5.3. Although this is a simple test, care is needed in sample preparation and temperature control for consistent results. This is reflected in the precision of the method where, for grades within BS 3690. reproducibility is given as ten per cent of the mean.
