AS 2341.3:2020 Methods of testing bitumen and related roadmaking products
1 Delete last sentence and replace with the following: The efficiency of the stirring and the balance between heat losses and heat input shall be such that the temperature of the bath medium does not vary by more than ±0.1 °C over the length of the viscometer, or from viscometer to viscometer in the various bath positions.
2 Delete Note 7 text and replace with the following:
Water is a suitable bath medium for determinations at 60 °C. Transparent paraffinic or silicone oils with a suitably high flashpoint (> 215 °C) have been found suitable for determinations at 135 °C.
Delete clause, including Note 8, and replace with the following: The following procedure has been found satisfactory for cleaning the viscometer. Remove the viscometer from the bath, invert it and hang it in the oven until the bitumen is drained thoroughly from it. The viscometer can then thoroughly be cleaned by washing with an appropriate solvent completely miscible with the sample, followed by, where necessary, a completely volatile solvent (cleaning agents are available commercially). The tube can be dried by sucking a slow stream of room air, through the capillary for at least 2 min.
The following should be used for determining the acceptability of results (refer to AS/NZS 2341.1) (95 % probability):
(a) Repeatability — Duplicate results by the same operator using the same equipment should not be considered suspect unless they differ by more than 7 % of their mean.
(b) Reproducibility — Results submitted by two laboratories should not be considered suspect unless the two results differ by more than 12 % of their mean.
Anx A2.3.1 First sentence, delete “Section 7” and replace with “Section 8”.
Anx A2.3.3 Delete second sentence.
Anx A2.3.4 Delete annex and replace with the following:
Allow the viscometer to remain in the constant temperature bath for 30 min ± 5 min to ensure the sample reaches temperature equilibrium.