ASTM D4957-08

This test method is useful for characterizing the flow behavior of asphalt emulsion residues and non-Newtonian bitumens. However, since non-Newtonian viscosity values depend on the level of shearing stress, its duration, and the shear history of the material, a non-Newtonian viscosity is not a unique material property. Instead, it is a parameter which is characteristic of the fluid-viscometer system under the conditions of the measurement procedure. Therefore, comparisons of non-Newtonian material behavior should only be made using apparent viscosities determined in similar viscometers under similar conditions of shearing stress and stress history. Procedures of sample preparation are especially important for repeatability or reproducibility of test results.

1.1 This test method describes procedures primarily designed to determine the apparent viscosities of residues obtained by distilling asphalt emulsions according to Test Method D 6997`. It is also recommended for use on non-Newtonian asphalts at any temperature within the capability of the apparatus. This test method is useful in characterizing rheological properties of non-Newtonian bitumens as a function of shear rate under the conditions of the test method. This test is run in straight open-end tube viscometers, normally at 60°C (140°F), but is suitable for use at other temperatures. It is applicable over the range from 5 to 50 000 Pa·s (50 to 500 000 P).

Note 1—The precision for this test method is based on determinations made at 60°C (140°F).

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.