Traffic paint plays an important role in maintaining the safety of roads. Subcommittee D01.44 on Traffic Coatings, part of ASTM International Committee D01 on Paint and Related Coatings, Materials and Applications, is currently working on two proposed new standards on the sampling of waterborne traffic paint and glass bead gradation measurement.
Waterborne Traffic Paint
Ensuring that traffic paint taken from the field is tested properly in laboratories is a concern of paint suppliers as well as private testing laboratories, Department of Transportation labs, DOT striping crews and striping contractors. A proposed new ASTM standard, WK22312, Practice for Drum and Tote Sampling of Waterborne Traffic Paint, addresses laboratory sampling issues.
According to Greg Shay, application and formulation development engineer, traffic paint, UCAR Emulsion Systems and Monomers, and chair of Task Group D01.44.02 on Traffic Paint and Liquid Traffic Markings, testing is done for qualification and/or to ensure that paint of a consistent quality is being provided to state striping crews and to striping contractors.
“If the sampling is not done properly, the sample may not be representative and could fail one or more specifications during testing, such as resin content or dry time,” says Shay.
Shay notes that there are two issues for field sampling of drums, totes and other traffic paint containers. “The first is that there is no common standard method being used for the sampling, and the second is that the various methods that are being used often do not provide a sample that is uniform and representative of the composite sample in the container.”
Interested parties are invited to join in the ongoing development of WK22312. “We would like to know how sampling is currently being done by the various state departments of transportation and contractors, and what methods or sampling equipment are available from vendors to obtain uniform samples,” says Shay.
Gradation of Glass Beads
Glass beads added to traffic paint during manufacturing are necessary to ensure the paint retroreflectivity, especially at night. A proposed new ASTM International standard, WK23758, Test Method for Measuring Gradation of Glass Beads Using a Flowing Stream Digital Image Analyzer, will be useful in the production and quality control of glass beads.
“Digital camera technology combined with high speed computers has yielded a very useful tool for determining accurate gradation analysis of glass beads,” says Gary Ware, vice president, R&D, SWARCO America, and an ASTM D01 committee member. “This proposed standard defines the first standardized test method for this application.”
Ware notes that, in addition to use by manufacturers, WK23758 will allow end users of glass beads to determine conformance to the standard.
“We welcome any and all input and participation, but technical people from the manufacturers of digital image analyzers are especially needed,” says Ware.
Technical Information: (WK22312) Greg Shay, UCAR Emulsion Systems and Monomers, Cary, N.C.
(WK23758) Gary Ware, SWARCO America, Columbia, Tenn.
ASTM Staff: Jeffrey Adkins