AASHTO M247 TYPE I glass beads Physics and chemistry function Item Standard Specific gravity g/ cm3 2.4--2.6 Refractive index e1.5 Spherical beads ( % ) > 80 The Sieve Analysis Mesh ( Micrometer) Percent passing ( % ) 850 97-100 600 70-90 300 15-35 150 0 -5 AASHTO M247 TYPE II Physics and chemistry function Item Standard Specific gravity g/ cm3 2.4--2.6 Refractive index e1.5 Spherical beads ( % ) > 70 The Sieve Analysis Mesh ( Micrometer) Percent passing ( % ) 600 100 425 90-100 300 50-70 180 0 -5 AASHTO M247 TYPE III Physics and chemistry function Item Standard Specific gravity g/ cm3 2.4--2.6 Refractive index e1.5 Spherical beads ( % ) > 80 The Sieve Analysis Diameter ( ¼ m) Passing ( % ) 1700 100 1400 95-100 1180 80-95 1000 10-40 850 0-5 710 0-2