玻璃微珠標準

740.10 Glass Beads. Inspection shall be done at the project site. Random samples shall be obtained from material delivered to the project site, or at other locations designated by the laboratory.

Type A. Glass beads for traffic paint shall conform to Supplement 1008 and to AASHTO M 247, Type 1 without flotation properties but coated for moisture resistance, with the following exception: 4.5 Flotation Test - Not applicable.

Type B. Glass beads for polyester marking material shall conform to AASHTO M 247, Type 1 with 50 ?5 percent flotation coating and 50 ?5 percent moisture resistant coating to be retained on each sieve, with the following exception: 4.5 Flotation Test. The Minimum percent floating shall equal 90 of flotation coated beads or 40.5 percent of total mixture. Glass beads for polyester marking material shall be packaged in bags designated "POLY".

Type C. Glass beads for thermoplastic material. Glass beads inter mixed or dropped on thermoplastic pavement marking material shall meet the following specification:

Sieve No. Percent Retained
1.18 mm (16) 3 Max
850 祄 (20) 5 to 20
425 祄 (40) 65 to 95
300 祄 (50) 0 to 5

Refractive Index: 1.50 to 1.60
Roundness: 80% Min.
Coating: Adhesion Promoting