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 x 2 x 0.48 inch (100 x 50 x 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.  Casting adhesives will follow a two-step acceptance procedure.

Step 1 will be materials testing and a flow test.

A.      Furnish adhesive material 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).

B.      For materials conforming to the above requirements provide samples of the adhesives to the Department for flow testing. The casting adhesive flow test will meet the ranges in Table 721.03-1.

The flow test procedure is:

1.      In a standard 2 × 4 block of pine wood (3.5 in wide × 1.5 in deep × 22 in long) cut a channel in the block that is 3/4 in wide by 1/2 in deep with a dado blade. The channel will run longitudinally 22 inches long in the center of the 3.5 inch wide face of the wood block. Use tape to block off the ends of the channel.

2.      Condition epoxy (Part A and Part B) and the wood block for a minimum of 4 hours at each of the three different temperatures (77, 100, and 120 °F).

3.      Mix Part A and Part B epoxy separately for 15 seconds.

4.      Mix Part A epoxy with Part B epoxy, at the manufacturer’s required ratio, for 1.5 minutes. The total amount of sample mixed will equal 40 mL.

5.      Temporarily dam off 6.5 inches of the channel at one end of the wood block. Keep the wood block flat and level with the channel side facing up.

6.      Pour mixed product into the blocked off end of the channel for 30 seconds. The product should fill this blocked off volume. Remove the temporary dam.

7.      Immediately place wood block with the epoxy filled channel on a 15 percent grade incline, with epoxy placed at the top of the slope.

8.      Immediately start a stop watch.

9.      Stop the watch when the material completely stops flowing in the channel.

10.    The time and length the epoxy traveled down the channel need to meet the requirements of Table 721.03-1.

11.    This test will be run at each of the three established temperatures.


Table 721.03-1




77 °F

(25 °C)

100 °F

(38 °C)

120 °F

(49 °C)

Distance (D) traveled down 15% incline (inches)

10 ≤ D ≤ 18

12 ≤ D ≤ 20

12 ≤ D ≤ 20

Time (T) for epoxy to stop flowing on 15% incline (minutes)

5 ≤ T ≤ 14

2 ≤ T ≤ 9

1 ≤ T ≤ 4


Step 2 will include a Department controlled field application and performance test

The epoxy adhesive will be field evaluated on two ODOT roadway projects in north eastern Ohio. One roadway will be new asphalt pavement and the other will new concrete or concrete that is less than 20 years old. The test sections on each roadway will be a minimum of 2 miles long and carry a minimum of 30,000 ADT. It will be the responsibility of the epoxy manufacturer to find routes in Ohio that meet these requirements and have them installed, at no cost to the Department, as a part of an existing ODOT contract. The casting adhesive will be evaluated after one year of service. Removal of any casting from the roadway after one year will be considered failure of the epoxy adhesive. If no castings are removed from the roadway and the product meets the requirements listed above, the epoxy adhesive will be granted Conditional Approval.

If the product continues to perform satisfactorily after 4 years, the product will be moved to Full Approval. If at any time during Conditional Approval status, the epoxy adhesive fails to perform to the satisfaction of the Department, it will be removed from Conditional Approval status and from further consideration.

Approved and Conditionally Approved materials will be incorporated on the Department’s QPL. Only furnish materials listed on the Department’s QPL.