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

 

644.03  Equipment.  Equip striping equipment for thermoplastic with a Data Logging System (DLS) for long line markings only.  Document the following with the DLS:

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

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.

Furnish the Engineer the above records for every route section painted by direction.  A route section is defined as a contiguous section of highway (without breaks) with the same route number designation. This normally matches the plan sub-summary.

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.

Furnish the Engineer the DLS manufacturer’s recommendations for equipment calibration frequency.  Calibrate and certify accuracy of the instrument on DLS.  Calibration tolerances for meters must not exceed +0.5 pounds per gallon (.06 kg/L) for glass beads.  Keep a clean, legible copy of calibration report and certifications performed by company personnel or instrument calibration companies with the paint truck.

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.

Furnish documentation that the application equipment, pump, extruding shoes and bead applicators are capable of applying the minimum millage and pounds (kilograms) of beads at 10 miles (16 km) per hour.  Do not operate above 10 miles (16 km) per hour without documenting the equipment’s capability to operate at a higher speed.

Ensure that the application equipment applies lines with a square end and can apply dashed lines.  Furnish documentation from the manufacturer that the equipment can do the work.

If applying surface-applied glass beads, 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.  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.  Spray thermoplastic equipment is permissible for 30 mil (1 mm) application.

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).  Document the following with DLS before any application, test and record the pavement surface, air temperature, dew point and record the temperature of the thermoplastic at the point of application.  Retest and record every 4 hours of operation.  Demonstrate to the Engineer the testing devices are accurate and operational.

Apply thermoplastic at a thickness of 125 mils (3 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 mm) thick heat-fused preformed thermoplastic (Item 647).

Apply thermoplastic at the following rates:

 

Pounds per Mile of Line

Width of Line (inches)

4

8

12

24

Solid Line

2340

4680

7020

14040

Broken Line

585

1170

1755

3510

Dotted Line

780

1560

2340

4680

Areas, Symbols, Words

133 pounds per 100 square feet

 

 

Kilograms per Kilometer of Line

Width of Line (mm)

100

200

300

600

Solid Line

650

1300

1950

3900

Broken Line

165

325

490

975

Dotted Line

220

435

650

1300

Areas, Symbols, Words

6.5 kg/m2

 

Mechanically dispense glass beads uniformly at a rate of 8 pounds (4 kg) of beads for each 100 square feet (10 m2) of thermoplastic surface area in a manner that provides uniformly retroreflective lines.  Do not place beads by hand, except to arrows and letters, and to complete the end of a line.  uniformly dispense hand-applied beads over arrows, letters, and ends of lines at a rate of not less than 8 pounds (4 kg) of beads for each 100 square feet (10 m2) of thermoplastic surface area in a manner that provides uniformly retroreflective lines.  The Contractor may leave small gaps in arrows or letters resulting from template use unfilled.

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 markings found to be more than 20 percent deficient, reapply full dimensional pavement markings with marking materials and glass beads at the application rate specified in 644.04 as a new application or apply minimum 30 mils additional material with glass beads as specified above to achieve 644.04 application thickness.

Material applied without written approval of the Engineer outside the temperature or application speed requirements will be considered unsatisfactory and will be replaced per 641.11 and 644.05.B.

Furnish the Engineer a report documenting each day’s marking application.  Include material types, quantities of each, pounds (kilograms) of materials used, application rate, marking batch numbers, pounds (kilograms) of beads used and DLS report documenting vehicle speed, air and surface temperatures,  and material thickness with date of application.

644.05  Layout and Premarking.

A.      Initial Thermoplastic Installation.  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.

B.      Subsequent Thermoplastic Installation (Repair or Refurbishing).  In addition to the requirements specified in 641.06, place markings over existing thermoplastic markings or portions thereof.  Before installing new thermoplastic, remove the existing thermoplastic markings by grinding so that the final combined thickness of the old and new thermoplastic is 130 mils (3 mm) and a clean, intact substrate is present.  Removal of existing thermoplastic markings shall be at the contract unit price for 644 Removal of Pavement Marking.

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 641.11, 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