ITEM 648 SPRAY THERMOPLASTIC PAVEMENT MARKING

 

648.01 Description

648.02 Materials

648.03 Equipment

648.04 Surface Preparation

648.05 Application

648.06 Basis of Payment

 

648.01 Description. This work consists of furnishing and applying spray thermoplastic pavement markings according to Item 641, 740.01, 740.09, 740.10, and the additional requirements specified below.

648.02 Materials. Furnish materials conforming to:

Spray Thermoplastic Pavement Marking.......................... 740.10

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 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.

648.03 Equipment. Equip all spray 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. 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 spray 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 is shown by carrying 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 spray thermoplastic and maintaining it at the proper temperature. Equip the kettle with a thermostat to control the temperature of the melted spray thermoplastic and to prevent overheating. Use equipment that continuously mixes and agitates the molten spray thermoplastic. Ensure that the parts of the equipment that convey the spray thermoplastic from the kettle to the application point maintain 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 spray thermoplastic material.

Ensure that the application equipment applies lines with a square end and can apply broken lines. Furnish application equipment for applying spray thermoplastic markings that produces different widths of lines.

Use equipment that ensures uniformity in the thickness and width of lines. Use equipment that forms lines 8 inches (200 mm) wide or less by one application pass.

648.04 Surface Preparation. Before applying spray thermoplastic the pavement surfaces must be clean, dust free, and completely dry. Test for moisture using the following test procedures, if needed as directed by the Engineer:

Moisture Test

1. Tape a 12 inch (300 mm) square sheet of thin plastic to the road surface, sealing all edges.

2. After 15 minutes examine the side of the sheet facing the road surface.

3. If more than a sparse amount of moisture is present, do not apply spray thermoplastic.

Apply spray thermoplastic to new pavement, over existing thermoplastic, or over one application of paint. Do not apply spray thermoplastic over epoxy, polyester, or preformed markings. Remove poorly adhering, flaking and loose markings and curing compounds. Use an air blast, or manual or mechanical broom to prepare surfaces. When more effort is needed to obtain a surface free from adhering, flaking and loose markings and curing compounds, use water blasting or mechanical removal.

648.05 Application. If applying spray 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 spray thermoplastic at the point of application is at least 375 °F (191 °C) and not more than 425 °F (218 °C).

Apply spray thermoplastic at a thickness of 45 mil (1.15 mm) at the following rates:

 

45Mil

Thickness

Line width (inch)

4

6

8

12

Pounds per Mile of Line

Solid Line

762-886

1143-1329

1524-1772

2286-2658

Broken or Dotted Line

191-222

286-332

381-443

572-666

 

1.15 mm

Thickness

Line Width (mm)

100

150

200

300

Kilogram per Kilometer of Line

Solid Line

209-242

313-364

417-485

626-728

Broken or Dotted Line

52-61

79-92

104-121

158-184

 

Mechanically apply glass beads to the wet spray thermoplastic surface so that the beads are embedded and retained and provide uniform retroreflectivity in the surface. Apply beads at a minimum rate of 10 pounds per 100 square feet (4.9 kg per 10 m˛) of spray thermoplastic surface area.

Use primer when required by the manufacturer. Apply primer according to the manufacturer’s recommendations.

For each route section on the DLS report, the Engineer will compute the amount of spray thermoplastic marking material and glass beads applied. The Department will reduce the contract price in direct proportion to the percent of deficiency of spray thermoplastic marking material or glass beads as specified in 648.05, 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 spray 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 648.05 without written approval of the Engineer. Replace spray thermoplastic markings and glass beads in all sections determined to be unsatisfactory by entirely removing the unsatisfactory spray thermoplastic material by grinding as per 641.10 and then reapplying at the full thickness specified in 648.05.

Furnish the Engineer daily, biweekly and final DLS reports conforming to 648.03, and additional reports indicating material type and quantities in pounds (kilograms) of spray thermoplastic materials used, as per 641.04.

648.06 Basis of Payment. The Department will not pay for any spray 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 648.05, measured according to 641.12, with the provisions specified in 641.13, and as follows:

Item           Unit                                Description

648             Mile (Kilometer)                 Edge Line, ____ inch (_____ mm),

648             Mile (Kilometer)                 Lane Line, ____ inch (_____ mm),

648             Mile (Kilometer)                 Center Line

648             Foot (Meter)                       Channelizing Line, ____ inch (_____ mm),

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

648             Foot or Square Foot           Removal of Pavement Marking

                      (Meter or Square Meter),

                      or Each

648             Lump Sum                          Two-Way Radio Equipment