REFLECTIVE TRAFFIC BEAD STUDY; 2ND INTERIM REPORT

THE PERFORMANCE OF DIFFERENT TYPES OF REFLECTIVE GLASS BEADS IN TRAFFIC PAINT APPLIED TO CONCRETE AND BITUMINOUS SURFACES IS DESCRIBED. FOUR DIFFERENT BEAD TYPES WERE EVALUATED AT APPLICATION RATES FROM 2 TO 7 LBS. PER GALLON OF PAINT. BEAD TYPES VARIED IN GRADATION AND WERE EITHER OF LOW (1.55+) OR INTERMEDIATE (1.65+) INDEX OF REFRACTION. RESULTS AFTER 10 MONTHS EXPOSURE ON A CONCRETE SURFACE INDICATED THAT: (1) BEAD APPLICATION RATES COULD NOT BE CONTROLLED TO AN ACCURACY GREATER THAN + OR - 2 LBS PER GALLON, (2) HUMAN EVALUATION CORRELATES WELL WITH A DEVELOPED PHOTOELECTRIC FIELD METHOD, (3) THERE APPEARS TO BE AN OPTIMUM RATE OF APPLICATION FOR EACH BEAD TYPE FOR BEST PERFORMANCE, (4) DIFFERENT BEAD TYPES PROVIDE DISTINGUISHABLE DIFFERENCES IN NIGHT VISIBILITY, (5) LOW INDEX, UNIFORMLY GRADED SMALL SIZE SPHERES APPEARED TO PROVIDE BEST PERFORMANCE. A PHOTOELECTRIC DEVICE FOR FIELD EVALUATION OF NIGHT VISIBILITY WAS DEVELOPED AND IS DESCRIBED. /BPR/

• Supplemental Notes:
  • Hpr, State NO 1484
• Corporate Authors:

  Colorado Department of Highways

  4201 East Arkansas Avenue
  Denver, CO  United States  80222

  Bureau of Public Roads /US

  400 7th Street, SW
  Washington, DC  United States  20590
• Publication Date: 1967-11

Subject/Index Terms

• TRT Terms: Aggregate gradation; Applications; Bituminous materials; Concrete pavements; Equipment; Evaluation; Glass beads; Night visibility; Performance; Refractivity; Surface treating; Traffic paint
• Uncontrolled Terms: Photoelectricity
• Old TRIS Terms: Bituminous surfacing; Gradation analysis; Reflective beads
• Subject Areas: Geotechnology; Highways; Materials; Research;

Filing Info

• Accession Number: 00215868
• Record Type: Publication
• Source Agency: Bureau of Public Roads /US
• Files: TRIS, STATEDOT
• Created Date: Mar 22 1994 12:00AM