The CKE furnishes an index, designated as the K factor, that indicates the aggregate particle roughness and surface capacity based on porosity.

The CKE is used as part of the Hveem mix design procedure to determine the approximate bitumen ratio (ABR), as shown in Appendix X1. However, there are other applications such as determining the coarse aggregate fraction constant (K_c) for use as an aid in selecting a bitumen content for open-graded friction courses.

Note 2—The quality of the results produced by this standard are dependant upon the competence of the personnel performing the procedure and the capability, calibration, and the maintenance of the equipment used. Agencies that meet the criteria of Standard Practice are generally considered capable of competent and objective testing / sampling / inspection / etc. Users of this standard are cautioned that compliance with alone does not completely assure reliable results. Reliable results depend on many factors: following the suggestions of or similar acceptable guideline provides a means of evaluating and controlling some of those factors.

1.1 This test method determines the centrifuge kerosine equivalent (CKE) of aggregate used in bituminous mixtures.

1.2 Units of Measure:

1.2.1 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. An exception is made in the values used for mass because this standard was originally developed using even values of grams, and use of ounces as a standard would make those measures cumbersome.

1.2.2 Regarding sieves, per ASTM Specification E11 Section 1.2, “the values stated in SI units shall be considered standard for the dimensions of the wire cloth openings and the diameter of the wires used in the wire cloth. The values stated in inchpound units shall be considered standard with regard to the sieve frames.” When sieve mesh sizes are referenced, the alternate inch-pound designations are provided for information purposes and enclosed in parentheses.

1.3 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. For specific hazard statements, see 7.1.