Individual User (Xiao)

1. General, Ceramic raised pavement markers shall consist of a heat-fired, vitreous, ceramic base, and a heat-fired, opaque, glazed surface to produce the properties required in these specifications. The markers shall be produced from any suitable combination of intimately mixed clays, shales, talcs, flints, feldspars, or other inorganic material which will meet the properties herein required. The markers shall be thoroughly and evenly marked and free from defects which effect appearance or serviceability.

The bottoms of the ceramic markers shall be free from gloss or glaze and shall have a number of integrally formed protrusions (comparable to a fine grained sandpaper) projecting from the surface in a uniform pattern of parallel rows. The tips of the protrusions shall not deviate more than one and three tenths (1.3) millimeters from a surface. Each protrusion shall have a face parallel to the bottom of the
Marker. To facilitate forming and mold release, the sides of each protrusion may be tapered. This taper shall not exceed seventeen (17) grads from perpendicular to the marker bottom.

2. Finish. The top surface of the marker shall be convex and the radius of the centimeter nearest the edge may be less. Any changed in curvature shall be gradual. The top and sides shall be smooth and free of mold marks, pits, indentations, air bubbles, or other objectionable marks or discolorations.
3. Adhesive. The retro reflective and ceramic raised pavement markers shall be secured by a bituminous compound for use in high temperature climates. The bituminous compound shall be selected and used in accordance with the manufacture's recommendations.