EMBEDMENT AND RETROREFLECTIVITY OF DROP-ON GLASS SPHERES IN THERMOPLASTIC MARKINGS
Embedment characteristics of drop-on moistureproofed and uncoated glass spheres and their subsequent retroreflectivity were evaluated subjectively in various types of hot-applied thermoplastic traffic markings by illuminating test panels in a dark room. In all of the hot-applied thermoplastic traffic marking types tested, uncoated drop-on spheres were generally overembedded because of positive wetting of the spheres by the thermoplastic traffic marking, and their retroreflectivity varied. The use of moistureproofed drop-on spheres in various thermoplastic traffic marking types resulted in optimal bead embedment with subsequent excellent retroreflectivity. The optimal rate of glass sphere application in all of the thermoplastic marking types was found to be 10 lb of moistureproofed glass spheres per 100 sq ft -- this rate enhanced retroreflectivity, bead embedment, and coverage. The retroreflectivity of the standard gradation of glass spheres may be enhanced in all of the thermoplastic types by increasing the percentage of spheres retained on U.S. sieves 30, 40, and 50 and by increasing the overall rounds from 70 to 80 percent.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/030904961X
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Supplemental Notes:
- This paper appears in Transportation Research Record No. 1230, Work-Zone Traffic Control and Tests of Delineation Material. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
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Authors:
- O'Brien, Jon
- Publication Date: 1989
Media Info
- Features: Figures; Photos; References; Tables;
- Pagination: p. 37-44
- Monograph Title: Work-zone traffic control and tests of delineation material
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Serial:
- Transportation Research Record
- Issue Number: 1230
- Publisher: Transportation Research Board
- ISSN: 0361-1981
Subject/Index Terms
- TRT Terms: Anchoring; Glass beads; Retroreflectivity; Road markings; Testing; Thermoplastic materials; Waterproofing
- Uncontrolled Terms: Application rate; Embedment
- Old TRIS Terms: Test results; Traffic marking
- Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;
Filing Info
- Accession Number: 00494757
- Record Type: Publication
- ISBN: 030904961X
- Files: TRIS, TRB, ATRI
- Created Date: Jun 30 1990 12:00AM