ITEM 607 – REFLECTIVE PAVEMENT STUDS
607.1 Description
This Item shall consist of furnishing and installing reflective pavement
studs on the surface of the pavement in accordance with this Specification
and at the locations shown on the Plans, or as required by the Engineer.
607.2 Material Requirements
607.2.1 Reflective Studs
Reflective studs shall be either the “Flush Surface” or “Raised Profile”
type having the following characteristics.
The “Flush Surface” reflector shall be the short base type having a maximum
base area of 180 mm x 140 mm. The base shall be formed in cast-iron with
adequate webbing to insure a firm key to the road when installed. The pad
shall be highly resilient and durable rubber reinforced with canvass and
shall have a design life of at least 5 years. The pad shall be so designed
as to produce a self-wiping action of the reflectors when depressed. The
reflectors shall be made of impact and abrasion-resisting glass and shall
be hermetically sealed into a copper socket.
The “Raised Profile” reflectors shall consist of an acrylic plastic shell
filled with an adherent epoxy compound molded from methyl methacyclate into
the shape of a shallow frustrum of a pyramid with base dimensions
approximately 100 mm x100 mm and thickness of not more than 20 mm. The
shell shall contain two prismatic reflectors each inclined at an angle of
300 to the horizontal and having an area not less than 20 cm 2. The reflectors shall attain the following standards for their
photometric and physical properties:
a) The reflectors shall have the minimum specific intensity values
expressed as candle power per foot-candle of illumination at the reflector
on a plane perpendicular to the incident light shown in Table 607.1.
Table 607.1 – Raised Profile Pavement Studs: Photometric Properties
Specific Intensity Values
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Color
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Crystal
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Yellow
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Red
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Divergence Angle
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0.2o
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0.2o
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2o
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Incidence Angle
0o
20o
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3.00
0.72
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1.20
0.75
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1.80
0.30
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Each reflector for testing shall be located with the center of the
reflecting face at a diameter of 1.5 m from a uniformly bright light source
having an effective diameter of 5 mm. The width of the photocell shall be
1.2 mm and shall be shielded from stray light. The distance from the
centers of the light source and photocell shall be 5 mm. Failure of more
than 4% of the reflective faces shall be a cause for rejection of the
complete batch.
The reflectors shall support a vertical load or kgf (10kN) when tested in
the following manner. A reflector shall be centered horizontally over the
open end of a vertically positioned hollow metal cylinders, 75 mm internal
diameter, 25 mm high and wall thickness of 6 mm. The load shall be applied
to the top of the reflector through a 6 mm diameter by a 6 mm high metal
plug centered on top of the reflector. Failure shall constitute either
breakage or significant deformation of the marker at any load less than
1000 kgf.
607.2.2 Adhesive
When “Raised Profile” type reflectors are specified, an approved two-part
epoxy adhesive shall be used.
607.2.3 Cement Mortar
Cement mortar shall consist of 1 part of Portland Cement to 2 parts of fine
aggregate with water added as necessary to obtain the required consistency.
607.3 Construction Requirements607.3.1 Flush Surface Type
The stud shall be installed into the pavement in accordance with the
manufacturer’s instructions but shall also comply with the following
requirements.
Cavities in the pavement shall be clearly cut to the dimensions of the
pavement stud and shall allow a clearance of 10 mm around the stud base.
The longitudinal centerline axis of the cavity shall be the same as that
required for the pavement stud when laid to the correct line and direction.
The walls of the cavity shall be splayed back at the angle of approximately
30o to the vertical to facilitate a “dove-tail” joint after the
mortar has set.
The bottom of the cavity shall be levelled with asphalt concrete prior to
placing the stud base which shall be pounded into position with a pounder
foot attached to the pneumatic drill.
The depth of the activity shall be such that when the stud base and
reflectors have been installed the elevation of the floor of the lens
socket shall not be greater than 2.0 mm or less than 1.0 mm above the
pavement surface.
When the studs are installed into a cement concrete pavement, the stud
shall be grouted into position with asphalt concrete containing fine
aggregate only or with a cement mortar as described in Subsection 607.2.3
above.
607.3.2 Raised Profile Type
The pavement studs shall be installed in accordance with the manufacturer’s
instructions.
607.4 Method of Measurement
The quantity of reflectorized pavement studs to be paid for shall be the
number of reflectorized pavement studs of either the flush surface type or
the raised profile type, whichever is called for in the Contract, installed
complete and accepted.
607.5 Basis of Payment
The quantities measured as described in Subsection 607.4, Method of
Measurement, shall be paid for at the contract unit price of the Pay Items
shown in the Bid Schedule, which payment shall constitute full compensation
for furnishing and placing all materials, excavating cavities, preparation
of surfaces, applying adhesive and mortar and for all labor, equipment,
tools and incidentals necessary to complete the Item.
Payment will be made under:
Pay Item No.
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Description
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Unit of Measurement
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607 (1)
607 (2)
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Reflectorized Pavement Stud (Flush Type)
Reflectorized Pavement Studs (Raised Profile Type)
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Each
Each
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