Optical Sizing and Roundness Determination of Glass Beads Used in Traffic Markings. Research Results Digest 346

摘要

This digest summarizes key findings from NCHRP Project 20-07, Task 243, 'Development of a Test Method for Optical Sizing and Roundness Determination of Glass Beads Utilized in Traffic Markings'. In NCHRP Project 20-07, Task 243, an interlaboratory study (ILS) was designed and conducted to (1) determine the precision and bias of both optical and traditional mechanical methods for different glass bead types (as defined in AASHTO M 247), (2) compare the precision and bias of various measurement methods, and (3) develop a practice in AASHTO standard format for the use of computerized optical methods and equipment to measure the size and roundness of glass beads used in traf- fic markings (see Appendix A).