ITEM 646  EPOXY PAVEMENT MARKING

646.01   Description
646.02   Materials
646.03   Equipment
646.04   Cleaning and Surface Preparation
646.05   Application
646.06   Method of Measurement
646.07   Basis of Payment

646.01  Description.  This work consists of furnishing and applying epoxy pavement markings according to 641, 740.01, 740.07, 740.09, and the additional requirements specified below.

Store and handle epoxy material according to all the applicable EPA and local environmental regulations and the manufacturer’s recommendations.

646.02  Materials.  Furnish materials from the Department’s Prequalified List conforming to:

646.03  Equipment.

A.     General.  Use equipment to apply epoxy pavement markings that has the following capabilities and features:

1.      Capable of mixing the epoxy components in proportions recommended by the manufacturer and applying glass beads simultaneously with line placement.

2.      Capable of applying epoxy at the specified thickness, width, and pattern.

3.      Individual material reservoirs, or space, for the storage of Part A and Part B of the epoxy.

4.      Heating equipment of sufficient capacity to maintain the epoxy components at the manufacturer’s recommended temperature, and to produce the required amount of heat at the mixing head and gun tip and maintain those temperatures with the tolerances recommended by the epoxy manufacturer for the spray application.

5.      Adequate individual tanks for the storage and dispensing of Size I and Size II glass beads.

6.      Individual dispensers for the simultaneous application of Size I and Size II glass beads at a rate up to 20 pounds per gallon (2.4 kg/L).

7.      Individual metering devices on the proportioning pumps (one indicator per pump) and stroke counters to monitor gallon (liter) usage.  Ensure that these devices are clearly visible.

8.      All the necessary spray equipment mixers, compressors, and other appurtenances to allow for the placement of reflectorized pavement marking systems in a simultaneous sequence of operations.

9.      A minimum 24-inch (600 mm) long static mixer unit or an equivalent system that produces properly mixed material.

10.    A completely enclosed flush and purge system to clean the lines and the guns without expelling any of the solution into the environment.

B.     Long Line Equipment.  Furnish a striper to apply long line epoxy markings that is:

1.      Truck-mounted and self-contained.
2.      Designed to spray the epoxy and glass beads in continuous and skip line.
3.      Maneuverable to the extent that straight lines can be followed and normal curves can be made in a true arc.

C.     Auxiliary Marking Equipment.  Furnish application equipment for auxiliary markings by either of the following two methods:

1.      Equip the striper with accessories for applying auxiliary markings.
2.      Use a portable applicator approved by the Engineer.

D.     Epoxy Measuring Device.  Furnish a calibrated measuring device, acceptable to the Engineer, to measure the epoxy resin in the striper tanks.

646.04  Cleaning and Surface Preparation.

A.     General.  Before applying epoxy, clean and prepare the pavement surface in the following sequence:

1.      Remove all debris, oil, and any other contaminants that may hinder the adhesion of the epoxy to the pavement.
2.      Use a power-broom to clean the pavement.
3.      Remove residue and debris with blasts of compressed air.
4.      Follow any additional manufacturer’s recommendations for surface preparation.

Perform operations in such a manner that the finished pavement surface is not damaged or unnecessarily scarred or left in a pattern that will mislead or misdirect the motorist and that minimizes airborne dust.  Avoid damage to transverse and longitudinal joint sealers.

B.     Asphalt Concrete Pavements.  In addition to the requirements of 646.04.A, the following apply.

Wait 48 hours after the placement of polymer modified asphalt-concrete pavement before preparing it for epoxy pavement markings.

For any other type of modified asphalt or for open graded friction course asphalts, contact the manufacturer for surface preparation recommendations.

Do not grind asphalt concrete pavements.

C.     Portland Cement Concrete Pavements.  On new portland cement concrete pavements, do not begin cleaning operations until a minimum of 30 days after the placement of concrete, unless otherwise directed by the Engineer.  In addition to the requirements of 646.04.A, the following apply.

Remove all curing compound and laitance on the concrete surface and in any textured pavement valleys.

Round the profiles of the peaks of textured pavement and remove sharp edges and irregularities.

Acceptable removal methods are:

1.      Sand blasting with containment.
2.      Blast track cleaning.
3.      High-pressure water blasting with or without abrasives and with sufficient time to allow the pavement to dry before applying epoxy markings.
4.      Other methods approved by the Engineer except that grinding is not permitted.

Contain and dispose of all the removal debris.

D.     Removal of Existing Markings.  When placing epoxy markings in the same place as existing pavement markings, remove at least 95 percent of the existing pavement markings.  Use a removal method that results in little or no color and texture changes in the surrounding pavement.

E.      Preparation Area.

1.      Lines.  Prepare an area that is the width of the new pavement marking, or existing line, plus 1-inch (25 mm) on each side and the length of broken lines plus 12 inches (300 mm) on each end.

2.      Arrows, Letters, and Symbols.  When cleaning for letters and symbols, prepare an area that is sufficiently large to accommodate the new marking, or to remove the existing marking.

646.05  Application.  Apply epoxy only when the surface is clean and dry and when the pavement and air temperature are above 50 ºF (10 ºC).  Transfer the entire contents of each material container to the striper tanks.  Keep the epoxy thoroughly mixed at all times during application.

Apply epoxy uniformly to the surface to be marked at a rate specified below.  To achieve the rate, ensure that the thickness of the applied epoxy is 20 mils ± 1 mil (500 mm ± 25 mm).

On open graded asphalts, increase the above rate by 25 percent to achieve the required thickness of 25 mils ± 1 mil (625 mm ± 25 mm).

Do not dilute the epoxy.

Apply enough glass beads to the uncured epoxy so that the beads completely fill the epoxy film from the film-pavement interface to the top surface of the film to the extent that there are loose beads on the surface of the uncured line.  Apply the glass beads at a rate of at least 25 pounds (3 kg) of beads per gallon (liter) of epoxy applied.  Drop glass beads onto the epoxy in a double-drop system with the large gradation (Size I) first and the regular gradation (Size II) second in the same pass of the equipment.  Apply the beads in equal amounts by weight.

Cease operations when any of the following conditions are observed:

A.     The marking does not consistently dry to a no-track condition.
B.      The marking has cyclical soft spots.

Resume marking operations when the Inspector is satisfied the problem is corrected.

646.06  Method of Measurement.  In addition to the requirements of 641.12, the following apply:

A.     The Contractor must submit certified documents from the manufacturer listing the amount of epoxy (in gallons/liters) and glass beads (in pounds/kilograms) shipped for the particular project.

B.      The Inspector will take stroke counter readings at the beginning and end of each day.  Turn off the stroke counter on the pump while re-circulating epoxy.  The Inspector will not use the “dipping the tank” method to measure the epoxy quantity used.

C.     The Engineer will verify the rates of epoxy and bead application by comparing the amount of materials used with the computed amount needed for each section.  Where short sections are involved and it is not practical or feasible to determine the quantities used on each and every short section, the Engineer will group such short sections together to verify the quantities applied.

646.07  Basis of Payment.  The cost of cleaning and surface preparation according to 646.04 is included in the unit bid cost for the various pavement markings.

The Department will make payment for accepted quantities at the contract prices, or prices adjusted according to 641.11, measured according to 641.12, with the provisions specified in 641.13, and as follows: