ASTM D6927-22

SIGNIFICANCE AND USE 4.1 Marshall stability and flow values along with density, air voids in the total mix, voids in the mineral aggregate, or voids filled with asphalt binder, or both, filled with asphalt binder are used for laboratory mix design and evaluation of asphalt mixtures. In addition, Marshall stability and flow can be used to monitor the plant process of producing asphalt mixture. Marshall stability and flow may also be used to relatively evaluate different mixes and the effects of conditioning such as with water. 4.1.1 Marshall stability and flow are asphalt mixture characteristics determined from tests of compacted specimens of a specified geometry. The Marshall Test can be conducted with two different types of equipment: (1) Method A—using a loading frame with a load ring and a dial gauge for deformation or flow meter (Traditional Method); or (2) Method B—using a load-deformation recorder in conjunction with a load cell and linear variable differential transducer (LVDT) or other automatic recording device (Automated Method). 4.1.2 Typically, Marshall stability is the peak resistance load obtained during a constant rate of deformation loading sequence. However, depending on the composition and behavior of the mixture, a less defined type of failure has been observed, as illustrated in Fig. 1. As an alternative method, Marshall stability can also be defined as the load obtained when the rate of loading increase begins to decrease such that the curve starts to become horizontal, as shown in the bottom graph of Fig. 1. The magnitude of Marshall stability varies with aggregate type and grading and bitumen type, grade, and amount. Various agencies have criteria for Marshall stability. FIG. 1 Flow Determination for Two Types of Specimen Failure 4.1.3 Marshall flow is a measure of deformation (elastic plus plastic) of the asphalt mixture determined during the stability test. In both types of failure, the Marshall flow is the total sample deformation from the point whe... SCOPE 1.1 This test method covers measurement of resistance to plastic flow of 4 in. (102 mm) cylindrical specimens of asphalt mixture loaded in a direction perpendicular to the cylindrical axis by means of the Marshall apparatus. This test method is for use with dense-graded asphalt mixtures prepared with asphalt binder (modified and unmodified) with maximum size aggregate up to 1 in. (25 mm) in size (passing 1 in. (25 mm) sieve). 1.2 Units—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. 1.3 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. 1.4 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.