scope:

This test method covers procedures for preparing and testing both laboratory-compacted and field-cored asphalt mixture specimens to determine the damage characteristic curve and fatigue analysis parameters via the direct tension cyclic fatigue test using the asphalt mixture performance tester (AMPT).

This standard is intended for dense-graded mixtures with nominal maximum aggregate size less than or equal to 19.0 mm (0.75 in.). Mixtures with a nominal maximum aggregate size greater than 19.0 mm (0.75 in.) should be tested following T 400.

This standard may involve hazardous material, operations, and equipment. This standard does not purport to address all safety problems 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.