USE OF HEMISPHERICAL BEADS AS PAVEMENT MARKING RETROREFLECTORS
Since preliminary theoretical calculations indicated that hemispherical beads may act as efficient retroreflectors on pavement markings even under wet conditions, a program of research was undertaken to carry out a systematic study on the effectiveness of the hemispherical beads both from theoretical and experimental points of view. The experimental studies included some actual field tests involving the regular automobile traffic flow conditions as well as a number of passes with snowplows. Studies with various size beads indicate as expected, that the smaller the size of the beads the greater the chance of survival under snow plowing conditions but with normal snowplow practices, with the blade grazing the pavement, no beads survive. These tests indicated that under normal traffic conditions, the chance of survival of the beads appears to be somewhat greater for the larger size beads. Circular Track Testing Facility of PSU indicate that with adequate curing at normal temperature, the survival of the beads under automobile traffic conditions is excellent.
Pennsylvania State University, University ParkMaterials Research Laboratory
University Park, PA USA 16802
Washington, DC USA 20590
- Vedam, K
- Shuler, L
- Publication Date: 1975-4-24
- Pagination: 80 p.
- TRT Terms: Concrete curing; Durability; Field tests; Glass; Glass beads; Grain size (Geology); Highway traffic control; Highways; Measures of effectiveness; Moisture content; Pavements; Plastics; Reflectorized materials; Retroreflectors; Road markings; Size; Snow removal; Snowplows; Traffic
- Uncontrolled Terms: Effectiveness; Wet conditions
- Old TRIS Terms: Beads; Markers; Traffic marking
- Subject Areas: Geotechnology; Highways; Materials; Operations and Traffic Management; Pavements; Vehicles and Equipment;
- Accession Number: 00092353
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: FHWA-RD-75- 67 Final Rpt.
- Contract Numbers: FH-11-8142
- Files: NTIS, TRIS, USDOT
- Created Date: Nov 5 1976 12:00AM