scope:

This test method covers the determination of the failure strain and failure stress of asphalt binders by means of a direct tension test. It can be used with unaged or aged material using T 240 (RTFOT) or R 28 (PAV), or both. The test apparatus is designed for testing within the temperature range from +6 to -36°C.

This test method is limited to asphalt binders containing particulate material having dimensions less than 250 μm.

This test method is not valid for specimens exhibiting a failure strain of greater than 10 percent considered outside the brittle-ductile range.

This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.

The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of R 18 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with R 18 alone does not completely assure reliable results. Reliable results depend on many factors; following the suggestions of R 18 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.