721  RAISED PAVEMENT MARKER MATERIALS

721.01  Raised Pavement Marker Castings.   Ensure that the casting is nodular iron according to ASTM A 536, hardened to 51-55 RC, snow plowable in the two opposing longitudinal directions and designed to accommodate a replacement prismatic retroreflector.

Furnish materials according to the Department’s Qualified Products List   (QPL).

721.02  Prismatic Retroreflector and Adhesive.  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.

 Furnish manufacturer recommended retroreflector adhesive to bond the prismatic retroreflectors to casting.

Furnish materials according to the Department’s Qualified Products List (QPL).

721.03  Casting Adhesive.  Furnish adhesive according 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).

Furnish materials according to the Department’s Qualified Products List (QPL).