Meaning and use

5.1 The gradation (size distribution) of glass beads has a significant effect on the reverse reflection efficiency of the pavement marking system.

5.2 This test method is used to characterize the gradation (size distribution) of glass beads for compliance testing against standard specifications for glass beads in pavement marking applications.

5.3 While the potential industrial applications of this test method extend beyond the measurement of the gradation (size distribution) of glass beads for pavement marking, these are beyond the scope of this standard.

ASTM D7681-11-2016 “Standard Test Method for Measurement of Glass Sphere Gradation with a Flow Digital Image Analyzer”

Step 1: Scope

1.1 The test method includes the use of a flow flow digital analyzer to determine the gradation (size distribution) of glass spheres used in pavement marking systems. Typical grades for pavement marking systems are defined in types 0 to 5 in AASHTO M247-08.

1.2 This test method provides for dimensional data to be provided in various forms to meet the requirements of the mechanism pavement marking material specification. For most specifications, the standard format is to display size data as a “percentage retained” or “percentage passed” relative to a range of standard U.S. screen sizes.

1.3 Values expressed in SI units shall be regarded as standard values. No other units of measurement are included in this standard.

1.4 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory restrictions prior to use.