ASTM D8668-26

1.1 This test method covers the determination of asphalt binder peak stress (t_f), peak stress energy (E_f), and peak strain (?_f) using the monotonic shear strength (MOSS) test. t_f, E_f, and ?_f can be used to measure the strength, toughness, and strain tolerance of an asphalt binder under constant shear loading. The MOSS test is conducted using the dynamic shear rheometer (DSR) utilizing monotonic shear loading, and can be performed on unaged or aged material, including materials conditioned in the rolling thin-film oven (RTFO) and pressure aging vessel (PAV).

1.2 The values stated in SI units are to be regarded as the standard.

1.3 A precision and bias statement for this test method has not been completed at this time. Therefore, this test method should not be used for acceptance or rejection of a material for purchasing purposes.

1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

5.1 This test method is designed to evaluate the shear strength, toughness, and strain tolerance of an asphalt binder under constant shear loading.

5.2 The peak stress is an indicator of the shear strength of an asphalt binder under constant loading at a given temperature or stiffness.

5.3 The peak stress energy is an indicator of the toughness of an asphalt binder under constant loading at a given temperature or stiffness.

5.4 The peak strain is an indication of the strain tolerance of the binder at a given temperature or stiffness.