721  RAISED PAVEMENT MARKER MATERIALS

721.00  General
721.01  Raised Pavement Marker Castings
721.02  Prismatic Retroreflector
721.03  Casting Adhesive
721.04  Prismatic Retroreflector Adhesive

721.00  General.  Furnish certified test results to the Director showing that the casting meets 721.01, the prismatic retroreflector meets 721.02, the casting adhesive meets 721.03, and the prismatic retroreflector adhesive meets 721.04.  Products meeting this specification are identified on a prequalified list kept on file by the Laboratory.  The Department does not require further testing or material certification of products on this list.  Changes in the product or poor performance in the field may be cause for removal from the list.

721.01  Raised Pavement Marker Castings.  Ensure that the casting is nodular iron conforming to ASTM A 536, hardened to 52-54 RC, snow plowable in the two opposing longitudinal directions and designed to accommodate a replaceable prismatic retroreflector.

721.02  Prismatic Retroreflector.  Furnish reflectors that contain one or two prismatic reflective faces to reflect incident light from a single or opposite directions.  Furnish reflectors with nominal dimensions of 4 ´ 2 ´ 0.48 inch (100 ´ 50 ´ 12 mm).  Ensure that the reflector fits securely in the recessed area and does not protrude above the profile of the casting.  Ensure that the prismatic retroreflector meets the requirements of Supplement 1062.

721.03  Casting Adhesive.  Furnish adhesive conforming to AASHTO M 237, Type IV, except that the viscosity is 200 to 900 poise at 77 + 2 °F (25 + 1 °C) and the unit weight is 11.3 to 11.9 pounds per gallon (1.35 to 1.43 kg/L).

721.04  Prismatic Retroreflector Adhesive.  Furnish adhesive to bond the prismatic retroreflectors to castings from the Laboratory’s approved list.