5.1 The critical strain energy release rate parameter, J_c, is used to compare the cracking resistance of asphalt mixtures prepared with different asphalt binder and aggregate types prepared to meet the volumetric requirements of differing traffic levels tested at intermediate temperatures.

5.2 The critical strain energy release rate parameter, J_c, is an engineering property and a performance indicator at intermediate temperature cracking.

Note 1: 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 Specification D3666 are generally considered capable of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Specification D3666 alone does not completely ensure reliable results. Reliable results depend on many factors; following the suggestions of Specification D3666 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.

1.1 This test method covers the procedures for preparation, testing, and measurement of asphalt mixture cracking resistance at intermediate temperatures using semi-circular bend (SCB) geometry of laboratory-prepared or pavement core asphalt mixture samples tested monotonically. The SCB sample is a half-disk with a notch cut aligned vertically in parallel with the testing loading. The test method describes the determination of the critical strain energy release rate parameter, J_c, and other parameters determined from the load-displacement curve. These parameters can be used to rank the resistance of asphalt mixtures to cracking.

1.2 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

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

1.4 Since a complete Precision and Bias statement for this standard has not been developed, the test method is to be used for research and informational purposes only. Therefore, this standard should not be used for acceptance or rejection of a material for purchasing purposes.

1.5 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.

1.6 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.