3.2.2.2
Primer
After surface preparation has been completed the asphalt and/or concrete
pavement surface shall be primed. The primer shall be applied with spray
equipment. Primer materials shall be allowed to "set-up" prior to applying
the thermoplastic composition. The asphalt concrete primer shall be
allowed to dry to a tack-free condition, usually occurring in less than 10
minutes. The Portland cement concrete primer shall be allowed to dry in
accordance with the thermoplastic manufacturer's recommendations. To
shorten the curing time of the epoxy resins an infrared heating device may
be used on the concrete primer.
a. Asphalt Concrete Primer: Primer shall be applied to all asphalt
concrete pavements at a wet film thickness of 0.10 mm 0.005 inch, plus
or minus 0.025 mm 0.001 inch (25-40 square meters per liter 265-400
square feet per gallon).
b. Portland Cement Concrete Primer: Primer shall be applied to all
concrete pavements (including concrete bridge decks) at a wet film
thickness of between 1.0 to 1.3 mm 0.04 to 0.05 inch (30-40 square
meters per liter 320-400 square feet per gallon).
3.2.2.3
Markings
After the primer has "set-up", the thermoplastic shall be applied at
temperatures no lower than 190 degrees C 375 degrees F nor higher than 220
degrees C 425 degrees F at the point of deposition. Immediately after
installation of the marking, drop-on glass spheres shall be mechanically
applied so that the spheres are held by and imbedded in the surface of the
molten material.
a. Extruded Markings: All extruded thermoplastic markings shall be
applied at the specified width and at a thickness of not less than 3.0
mm 0.125 inch nor more than 5.0 mm 0.190 inch.
b. Sprayed Markings: All sprayed thermoplastic markings shall be
applied at the specified width and the thicknesses designated in the
contract plans. If the plans do not specify a thickness, centerline
markings shall be applied at a wet thickness of 2.0 mm 0.090 inch, plus
or minus 0.10 mm 0.005 inch, and edgeline markings at a wet thickness
of 1.5 mm 0.060 inch plus or minus 0.10 mm 0.005 inch.
c. Reflective Glass Spheres: Immediately following application,
reflective glass spheres shall be dropped onto the molten thermoplastic
marking at the rate of 1 kg/2 square meters 1 pound per 20 square feet
of compound.
3.2.3
Preformed Tape
The pavement surface temperature shall be a minimum of 15 degrees C 60
degrees F and the ambient temperature shall be a minimum of 15 degrees C 60
degrees F and rising. The preformed markings shall be placed in accordance
with the manufacturer's written instructions.
3.2.4
Raised Reflective Markers
Prefabricated markers shall be aligned carefully at the required spacing
and permanently fixed in place by means of epoxy resin adhesives. To
SECTION 02763A
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