A STUDY OF GLASS BEADS FOR REFLECTORIZING TRAFFIC PAINT

GLASS BEADS PROVIDE THE BEST CURRENTLY KNOWN MEANS OF IMPROVING THE NIGHT VISIBILITY OF PAINTED STRIPES BECAUSE OF THEIR OPTICAL PROPERTIES WHICH CAUSE THE LIGHT RAYS OF HEADLIGHTS TO BE RETURNED TO THE DRIVER BY REFLEX-REFLECTION, THUS PROVIDING A PAINT STRIPE WITH POSITIVE AND STRIKING VISIBILITY. IN ADDITION, THE COLOR OF THE BINDER IS MAINTAINED. BECAUSE OF THE DIFFERENCES IN PHYSICAL AND CHEMICAL PROPERTIES OF AVAILABLE GLASS BEADS, EIGHT DIFFERENT GLASS BEADS OBTAINED FROM FOUR MANUFACTURERS WERE STUDIED. THE BEADS WERE GRADED FROM THE NO. 20 TO THE NO. 100 SIEVE. FOLLOWING THE STANDARD STRIPING PROCEDURE USED IN MISSOURI, ALL BEADS WERE APPLIED BY GRAVITY ON THE SURFACE OF THE FRESHLY APPLIED PAINT. THIS PROCEDURE PROVIDES IMMEDIATE REFLECTANCE AND THE GRADING OF THE BEADS PROMOTES MAINTENANCE OF REFLECTION SINCE THE DIMINISHING SIZES BECOME EXPOSED AS THE BINDER WEARS AWAY. STANDARD MISSOURI SPECIFICATION YELLOW TRAFFIC PAINT WAS USED FOR THE BINDER. LABORATORY TESTS FOR CHEMICAL COMPOSITION AND PHYSICAL CHARACTERISTICS INCLUDING GRADATION, INDEX OF REFRACTION, STRUCTURAL STABILITY, SOLUBILITY IN ACID, AND FREEZING EFFECTS, WERE MADE. A LABORATORY METHOD FOR PREPARING BEADED PAINTS, AND APPARATUS DEVELOPED DURING THE INVESTIGATION ARE DESCRIBED. FIELD TESTS INCLUDED ACCELERATED (TRANSVERSE) AND UNACCELERATED (LONGITUDINAL) INSTALLATIONS. PERIODIC REFLECTANCE MEASUREMENTS OF THE FIELD STRIPES WERE MADE WITH THE HUNTER NIGHT-VISIBILITY METER AND THE STRIPES WERE EXAMINED UNDER A 20X GLASS TO DETERMINE BEAD DAMAGE AND LOSS. VISUAL OBSERVATIONS WERE MADE AND FOUND TO BE IN AGREEMENT WITH THE HUNTER METER. A PHOTOGRAPHIC METHOD FOR MAINTAINING A PERMANENT RECORD OF THE VISUAL APPEARANCE OF THE STRIPES AT NIGHT IS DESCRIBED. /AUTHOR/

  • Supplemental Notes:
    • Vol 29, pp 245-273, 5 FIG, 10 TAB, 4 PHOT, 9 REF, 1 APP
  • Authors:
    • Lyon, V H
    • Robinson, D L
  • Publication Date: 1950

Media Info

  • Monograph Title: Proceedings of the Twenty-Ninth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 13-16, 1949.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00217115
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 25 1971 12:00AM