ITEM 644  THERMOPLASTIC PAVEMENT MARKING

644.01  Description

644.02  Materials

644.03  Equipment

644.04  Application

644.05  Layout and Premarking

644.06  Basis of Payment

 

644.01  Description.  This work consists of furnishing and applying screed extruded thermoplastic pavement markings according to Item 641, 740.01, 740.04, 740.09, and the additional requirements specified below.

644.02  Materials.  Furnish materials from the Department’s Approved List conforming to:

Thermoplastic pavement marking........................... 740.04

Glass beads, Type C............................................... 740.09

 

The Engineer may obtain random samples from the application equipment.  Furnish the manufacturer’s identification information for the sampled liquid materials.  The Department will test the quality assurance sample for conformance to the manufacturer’s production ranges.  Samples not meeting the manufacturer’s production ranges will require the Contractor to re-apply, at his expense, any markings using that sample.  All other untested batches will become not approved materials and will either require testing or re-application.

Do not apply material that has exceeded the manufacturer’s shelf life.  Do not use glass beads that are wet.

 

644.03  Equipment.  Equip all thermoplastic pavement marking trucks for center line, lane line and edge line markings with a computerized Data Logging System (DLS), including a cab mounted display which shows the actual bead application rate.  A DLS is not required for markings applied with hand carts.  For center line, lane line and edge line markings applied with truck-mounted equipment, when the length of marking exceeds 0.5 miles (0.8 km) of continuous line equivalent, document the following with the DLS:

1.  Measure and record application vehicle speed to the nearest 0.1 MPH (0.16 km/h).

2.  Measure and record pavement surface temperature.

3.  Measure and record air temperature.

4.  Measure and record thermoplastic temperature in the kettle and at the point of application.

Record as a separate DLS report line entry the above information for each route section painted, when the length of marking exceeds 0.5 miles (0.8 km) of continuous line equivalent. A route section is defined as one direction of a contiguous section of highway (without breaks) with the same route number designation.

If the DLS equipment fails, finish that day’s work only and resume when the DLS equipment is working.

The Department will provide a standard DLS spreadsheet, which prescribes the correct DLS report format and content prior to beginning of work.

Each DLS shall have an annual calibration of all mechanical and electrical components and its software function and output confirmed by the DLS manufacturer or their designated representative. Evidence of the annual calibration shall be carried by a signed and dated stamp or seal affixed to the inside of the driver’s door of each striper.

Use application equipment that includes a kettle for melting the thermoplastic and maintaining it at the proper temperature.  Equip the kettle with a thermostat to control the temperature of the melted thermoplastic and to prevent overheating.  Use equipment that continuously mixes and agitates the molten thermoplastic.  Ensure that the parts of the equipment that convey the thermoplastic from the kettle to the application point maintains it at the required temperature.

Attach an automatic bead dispenser to the equipment so that the beads are immediately and uniformly dispensed over the marking surface.  Equip the bead dispenser with an automatic cut-off control synchronized with the cut-off of the thermoplastic material.

Ensure that the applicator portion of the equipment has a shoe that rides on the pavement and extrudes the thermoplastic.  Ensure that the application equipment applies lines with a square end and can apply broken lines.  Furnish application equipment for applying screed extruded markings (no ribbon application) that consists of dies of varying widths to produce different widths of lines.  Do not use pans, aprons, or similar devices that the die overruns.

Use equipment that ensures uniformity in the thickness and width of lines.  Use equipment that forms lines 12 inches (300 mm) wide or less by one application pass, and lines wider than 12 inches (300 mm) by no more than two passes.  Do not allow individual passes to overlap or to be separated by a gap greater than 1/4 inch (6 mm).

644.04  Application.  If applying thermoplastic to pavements that are less than six months old, ensure that both the pavement surface and the ambient air temperature at the time of application are not less than 50 °F (10 °C) and rising.  However, if applying thermoplastic to pavements that are older than a year, ensure that both the pavement surface and the ambient air temperature at the time of application are not less than 70 °F (21 °C) and rising.  Ensure that the temperature of thermoplastic at the point of application is at least 400 °F (204 °C) and not more than 440 °F (227 °C). 

Apply thermoplastic at a thickness of 125 mils (3.2 mm).  Thermoplastic for small quantities or auxiliary markings up to 100 feet (30 m) in length can be exchanged as equal in function and price with 125 mil (3.2 mm) thick heat-fused preformed thermoplastic (Item 647).

Apply thermoplastic at the following rates:

125 Mil Thickness

Line Width (inch)

4

8

12

24

Pounds per Mile of Line

Solid Line

2340

4680

7020

14040

Broken Line

585

1170

1755

3510

Dotted Line

585

1170

1755

3510

Areas, Symbols, Words

133 pounds per 100 square feet

 

3.2 mm Thickness

Line Width (mm)

100

200

300

600

Kilograms per Kilometer of Line

Solid Line

650

1300

1950

3900

Broken Line

165

325

490

975

Dotted Line

165

325

490

975

Areas, Symbols, Words

6.5 kg/m²

 

Mechanically apply glass beads to the wet thermoplastic surface so that the beads are embedded and retained and provide uniform retroreflectivity in the surface.  Do not place beads by hand, except to symbols and words, and to complete the ends of lines.  Apply beads at a minimum rate of 12 pounds per 100 square feet (6 kg per 10 m²) of thermoplastic surface area.  The Contractor may leave small gaps unfilled in symbols and letters resulting from template use.

If required, furnish primer, and apply it according to the manufacturer’s recommendations.  Use primer except on new asphalt pavement.

Do not apply thermoplastic by spraying.

For each route section on the DLS report, the Engineer will compute the amount of thermoplastic marking material and glass beads applied.  The Department will reduce the contract price in direct proportion to the percent of deficiency of thermoplastic marking material or glass beads as specified in 644.04, up to 20 percent for each material deficiency.  The Department will only use the greater deficiency of marking material or glass beads to compute the deduction.

If the deficiency of thermoplastic marking material or glass beads is 20 percent or more, the Department will consider the work unsatisfactory.  In addition, the Engineer will consider as unsatisfactory materials applied outside the temperature or application requirements in 644.04 without written approval of the Engineer.  Replace thermoplastic markings and glass beads in all sections determined to be unsatisfactory by entirely removing the unsatisfactory thermoplastic material by grinding as per 641.10 and then reapplying at the full thickness specified in 644.04.  Do not apply a layer of sprayed thermoplastic to sections determined to be unsatisfactory to achieve the required thickness.

Furnish the Engineer daily, biweekly and final DLS reports conforming to 644.03, and additional reports indicating material type and quantities in pounds (kilograms) of thermoplastic materials used, as per 641.04.

644.05  Layout and Premarking.  In addition to the requirements specified in 641.06, only place auxiliary markings on new pavement.  The Contractor may place initial thermoplastic markings over work zone traffic paint markings.

644.06  Basis of Payment.  The Department will not pay for any thermoplastic lines that do not meet the required thickness.  The Department will pay for accepted quantities at the contract prices, or prices adjusted according to 644.04, measured according to 641.12, with the provisions specified in 641.13, and as follows:

Item           unit                                Description

644             Mile (Kilometer)             Edge Line

644             Mile (Kilometer)             Lane Line

644             Mile (Kilometer)             Center Line

644             Foot (Meter)                   Channelizing Line

644             Foot (Meter)                   Stop Line               

644             Foot (Meter)                   Crosswalk Line

644             Foot (Meter)                   Transverse/Diagonal Line

644             Each                                Handicap Symbol Marking

644             Each                                Railroad Symbol Marking, __ inch (__ mm)

644             Each                                School Symbol Marking, __ inch (__ mm)

644             Foot (Meter)                   Parking Lot Stall Marking

644             Each                                Lane Arrow

644             Each                                Word on Pavement, ___ inch (___ mm)

644             Foot (Meter)                   Dotted Line, ___ inch (___ mm)

644             Foot or Square Foot        Removal of Pavement Marking
                       (Meter or Square            
                       Meter), or Each

644             Lump Sum                      Two-Way Radio Equipment