ASTM D7405-08a

This test method is used to identify the presence of elastic response in a binder and the change in elastic response at two different stress levels. Non-recoverable creep compliance has been shown to be an indicator of the resistance of an asphalt binder to permanent deformation under repeated load.

This test method is also useful as a surrogate for other test methods used to measure elasticity in asphalt binders such as Test Method D 5801 (Toughness and Tenacity), Test Method D 6084 (Elastic Recovery), and Test Method D 7175 (DSR phase angle).

1.1 This test method covers the determination of percent recovery and non-recoverable creep compliance of asphalt binders by means of Multiple Stress Creep and Recovery (MSCR) testing. The MSCR test is conducted using the Dynamic Shear Rheometer (DSR) at a specified temperature.

1.2 This standard is appropriate for unaged material, material aged in accordance with Test Method D 2872 (RTFO), material aged in accordance with Practice D 6521 (PAV), and material aged in accordance with both Test Method D 2872 and Practice D 6521.

Note 1—The majority of development work on this test method was performed on material aged in accordance with Test Method D 2872 (RTFO).

1.3 The percent recovery is intended to provide a means to determine the presence of elastic response and stress dependence of polymer modified and unmodified asphalt binders.

1.4 A precision and bias statement for this standard has not been developed at this time. Therefore, this standard should not be used for acceptance or rejection of a material for purchasing purposes.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 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.