Increase Safety with Glass

This article provides an overview of the use of glass beads to increase the visibility of pavement markings. Glass beads - embedded in liquid binder - bend light, creating retroreflectivity of pavement markings. This retroreflective light is reflected back to the viewer, making the markings easier to see. Beads are most often used on crosswalk intersections, highway, and airport markings. Contractors adding glass beads to their marking application can choose from several kinds and sizes of glass beads. Generally, the bigger the bead, the more reflection. Often, the size of the glass beads is specified by a governing agency. Glass beads previously needed to be applied by hand, but manufacturers have introduced applicator units to replace this manual method. The units offer directional application of glass beads and an improved concentration of the beads on the marking. Glass beads also can be incorporated into preformed thermoplastics. Although the most important benefit of glass beads is the safety factor, glass beads also offer a protective coating for the marking. Glass beads offer many benefits, but contractors and customers also need to consider maintenance issues. Beads are shiny when first applied but they can dull and lose their retroreflectivity as they are exposed to the elements. Beads can also dislodge from the material causing the marking to lose retroreflectivity. Factors affecting bead longevity include: temperature, humidity, weather during application; condition and type of surface being marked; amount of beads and binder being applied; average daily traffic; uniformity of glass beads; proper application of binder and beads; quality of products being applied; and conditions markings and beads are exposed to after application. It is recommended that marking be redone and glass beads be added at least once or twice a year.


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  • Accession Number: 01155544
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 21 2010 7:57AM