ITEM 621 RAISED PAVEMENT MARKERS (RPM)
621.01
Description
621.02
Materials
621.03 Layout
621.04 Installation
RPM Casting
621.05
Installation RPM Retroreflector
621.06
Reflector Replacement
621.07
Reflector Color
621.08 Raised
Pavement Markers Removed
621.09 Method
of Measurement
621.10 Basis of
Payment
621.01 Description. This work consists of
preparing the pavement and furnishing and placing plowable
raised pavement marker castings (RPMs) and prismatic retroreflectors, and removing existing RPMs
for disposal.
621.02 Materials. Furnish materials conforming
to:
Castings...................................................................
721.01
Prismatic Retroreflectors and Adhesive................... 721.02
Casting
adhesive...................................................... 721.03
621.03 Layout. Before placing RPMs, lay out the location of all RPMs.
Locate RPMs within 5 percent of specified
spacing. Do not place RPMs under the following
conditions:
A.
On pavement surfaces with cracking, spalling, or
failure of underlying base material.
B.
Within 1 foot (0.3 m) of active signal detector loop wires. Exercise care
to ensure that detector lead-in cables are not cut.
C.
Over pavement markings except with the Engineer’s approval.
D.
Closer than 2 inches (50 mm) to a pavement construction (transverse or
longitudinal) joint or within an intersection.
E.
Within 3 feet (1 m) of a bridge expansion joint.
If
the initial location of a RPM is determined to violate one of the
aforementioned conditions, relocate the affected RPM longitudinally.
Relocate the RPM within a distance not exceeding 25 percent of the specified
RPM spacing. If necessary to relocate the RPM to a distance greater than
25 percent of the specified RPM spacing, do not install the affected RPM.
RPMs along double
yellow centerline are to be placed in line or on line, but no closer than 2
inches (50 mm) to a pavement construction (transverse or longitudinal)
joint. RPMs installed along a channelizing line
are to be placed no more than 1 inch (25 mm) from the edge of the painted line
and no closer than 2 inches (50 mm) to a pavement construction (transverse or
longitudinal) joint. Place the RPMs
installed along a lane line or dashed yellow centerline between and in line
with the dashes no closer than 2 inches (50 mm) to a pavement construction
(transverse or longitudinal) joint.
Install
replacement RPMs within 3 feet (0.9 m) longitudinally
of the damaged or missing RPM.
621.04 Installation RPM Casting. Cut
parallel slots with 1/16 to 1/8 inch (1.5 to 3 mm) clearance on each side for
installing RPM castings.
Pavement
cuts should be inspected prior to adding casting adhesive.
When
a casting is inserted in the cut without casting adhesive to test proper cut,
at least 3 of the 4 leveling lugs/tabs must contact the pavement surface and all
four keel-ends of castings must be below the pavement surface.
Each
casting must be centered lengthwise and should have 1/16 to 1/8 inch (1.5 to 3
mm) clearance between pavement cut and casting for casting adhesive to bond
properly. Only the leveling lugs/tabs should be in contact with the
pavement surface after insertion of casting in pavement so that a minimum of
1/16 inch (1.5 mm) of casting adhesive is the bonding adhesive between the
casting and pavement. The casting adhesive must fill all voids.
The
pavement cut must be completely dry and free of dust, dirt or any other
material that will interfere with the adhesive bond to the casting and the
pavement. Casting adhesive on the active reflector face must be removed
immediately.
Install
the RPM casting within 24 hours after cutting the slots into the
pavement. On new pavement surfaces, the Contractor may begin RPM
placement as soon as the pavement markings for that section are completed and
dry.
Ensure
that the RPM casting is free of dirt, dust, oil, grease, rust, moisture, or any
foreign matter that impairs adhesion to the pavement.
Place
RPMs when the pavement surface temperature and the
ambient air temperature are at least 40 °F (5 °C) and the pavement is
dry. Heat both parts of the RPM casting adhesive to 100 ± 10 °F (38 ± 5
°C) during installation when either the pavement surface or ambient air
temperature is between 40 and 50 °F (5 and 10 °C).
Ambient Air Temperature |
Minimum Period Protected from Traffic |
|
°F |
(°C) |
Minutes |
100 |
(38) |
15 |
90 |
(32) |
20 |
80 |
(27) |
25 |
70 |
(21) |
30 |
60 |
(16) |
35 |
50 |
(10) |
45 |
40 |
(5) |
60 |
Do not allow
traffic on the RPMs until the adhesive has cured.
Two component approved
casting adhesive is used to fill the pavement cut to within approximately 3/8
inch (9 mm) of the top of the pavement cut. A minimum of 3 of the 4
leveling lugs/tabs must be in contact with the pavement surface and the casting
adhesive should ooze out from under the casting from all sides filling all
voids around the casting and be level with the pavement surface.
Mix the casting
adhesive according to the manufacturer’s recommendations. Complete the
mixing operation and placing of the RPMs rapidly.
Do not use any mixed batch that becomes so viscous that it cannot be readily
extruded from under the RPM with light pressure.
621.05 Installation RPM Retroreflector.
Attach
the reflector to the casting before installation or after the adhesive in the pavement
slots has cured.
Remove all dirt,
dust, oil, grease, rust, moisture, parts of damaged reflectors, or any foreign
matter that impairs adhesion of the reflector to the casting.
Peel the release
liner from the back of the reflector with butyl pad. Apply a wide bead
(approximately 3/8 inch (9 mm)) of reflector
adhesive sufficient to squeeze out on all sides when pressure is applied to
seat the reflector.
Apply
approximately 100 pounds (45 kg) of pressure on the reflector or foot pressure
for 1 to 3 seconds. Do not allow adhesive material on the reflective
surface of the reflector. Any adhesive on the active reflector must be
removed immediately.
Apply the
reflector when the pavement surface temperature and the ambient air temperature
are at least 35 °F (2 °C) and the casting surface is dry. Do not
attach the reflector to the casting when rain over the work site is imminent.
621.06 Reflector Replacement. Replace
damaged, non-retroreflective, or missing reflectors within
the existing marker installations where the casting remains intact with the
appropriate reflector type. The Engineer will determine the location of
replacement reflectors.
Perform
the cleaning and attachment procedure for replacing reflectors within existing
RPM installations according to 621.05.
621.07 Reflector Color. Use the appropriate
reflector color for the following applications:
A. Channelizing Lines. White/red two-way reflectors
with white facing traffic.
B. Lane Lines. White one-way or white/red two-way reflectors
as specified, with white facing traffic.
C. Edge Lines. One-way reflectors facing
traffic matching the edge line color or two-way reflectors with the edge line
color facing traffic and red in the opposite direction.
D. Center Lines. Yellow two-way reflectors.
621.08 Raised Pavement Markers Removed. As
designated, remove existing raised pavement markers. Fill all depressions
caused by removing the castings with asphalt concrete by the end of the next
workday. Remove all standing water from the hole before filling.
Compact the asphalt concrete flush with the pavement. Removed raised
pavement markers become the property of the Contractor.
621.09 Method of Measurement. The
Department will measure RPMs by the number of each
furnished, complete with reflectors, in place, and accepted.
The
Department will measure RPM, Reflectors by the number of each, complete in
place, for use on existing RPM castings in the pavement, and accepted.
The
Department will measure Raised Pavement Markers Removed by the number.
Payment will include the cost of asphalt concrete to fill depressions caused by
removal of the castings.
621.10 Basis of Payment. The
Department will pay for accepted quantities at the contract prices as follows:
Item
Unit
Description
621
Each
RPM
621
Each
RPM Reflector
621
Each
Raised Pavement Marker Removed