Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 1 - ROADS, Second Edition 2020)

Epoxy adhesive shall be maintained at a temperature of 15° to 29° C before use and during
application.

Catalyst shall be added to the base just before the use and mixed to a smooth, uniform blend.
Unused mixed adhesive shall be discarded when catalytic action has caused stiffening and reduction
of workability or a small ball of jelled resin has formed in the center of the container.

Any voids in the base of the marker shall be filled with adhesive before placing the marker on the
road surface unless approval has been obtained from the Engineer to an amended procedure.
Generally, the Engineer will require a written recommendation from the marker manufacturer to
justify the amended procedure.

Excess adhesive shall be placed on the marker or the road surface such that after placing the marker
on the road surface the following requirements are met:

•

There are no voids in the adhesive beneath the marker;

•

A small bead of adhesive has exuded from the full perimeter of the marker base; should the

bead of adhesive rise above the base of the marker on any edge beneath reflective elements
the excess adhesive shall be removed;

•

Any adhesive on the body or lens of the marker shall be removed without damaging the marker;

Where stem type markers are installed the hole to accommodate the stem shall be filled with the
same adhesive used to fix the marker to the pavement.

a. Application Procedure with Epoxy Adhesives

RPMs shall be of the type indicated on the Contract plans and shall be fixed in the positions approved
by the engineer.

Contractor shall protect RPMs against impact until the adhesive has hardened. A displacement of
not more than one centimeter, left or right of the established guide line will be permitted. Contractor
shall remove and replace at the Contractor

’s own expense all improperly placed markers.

Reflective RPMs shall be installed in such a manner that the reflective face of the marker is
perpendicular to a line parallel to the roadway center line. No pavement markers shall be installed
over longitudinal or transverse joints of the pavement surface.

Adhesive shall be machine-

mixed and applied in accordance with the manufacturer’s

recommendations.

1. Standard Adhesive Set: On roadway sections that are not open to public traffic, it shall not

be necessary to preheat the markers provided the adhesive develops the required bond
strength of 124 gm/ cm

in less than 3 hours.

2. Rapid Adhesive Set: On roadway sections that are open to public traffic, the Contractor shall

preheat the roadway surface and the markers so as to insure the bonding of the marker in
not more than 15 minutes. Bonding will be considered satisfactory by the Engineer when
adhesive develops a minimum bond strength in tension of not less than 124 gm/cm

within

15 minutes.

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8.4.3.4

Recessed Raised Pavement Marker

Recessed raised pavement markers, when specified, shall be installed at the locations shown on the
Contract plans. All recessed RPMs shall have an abrasion resistant coating. Contractor shall prepare
the surface in and install RPMs in the recess in accordance with Article 8.4.3.1.

Contractor shall construct recesses for RPMs by grinding the pavement at a 40:1 slope in
accordance with the dimensions shown in Figure

8-2

. Taper lengths will be approximately 95 to 110

mm in length at a 40:1 slope.

Figure 8-2 Recessed RPM configuration

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Portion of ground mounted guide post installed below ground may be the same material as the
portion above ground or other durable material suitable for firmly anchoring the post in the ground.
When iron or steel are used for the in ground portion, they shall be galvanized in accordance with
AASHTO M 111.

Top of tubular posts shall be closed to prevent moisture or debris from entering. Surface mounted
guide  posts  shall  be  mounted  on  a  base  made  of  a  rigid  high  impact  resistant  material  and  be
resistant to ultraviolet light, ozone, and hydrocarbons. Post shall mount directly into or onto the base
in a tamper proof manner and shall allow for easy replacement. Guardrail mounted guide posts shall
be  the  same  as  ground  mounted  guide  posts  except  the  length  shall  be  adjusted  to  meet  the
mounting height requirements in the Contract plans. Appropriate holes shall be provided for fastening
the guide post to the guard rail post.

Material composition of flexible guide posts subsequently furnished shall not vary from that of the
samples upon which approval is based. If analysis reveals there is a change in material composition,
such change shall constitute grounds for rejection.

Post system shall be designed for permanent installation to resist overturning, twisting, and
displacement from wind and impact forces. Each flexible guide post shall be permanently identified
with the manufacturer’s name, and the month and year of fabrication. Ground mounted guide posts
shall have a permanent a mark indicating the recommended burial depth. Letters shall be solvent
resistant, a minimum of 6 mm in height, and permanently affixed to the post.

Unless otherwise specified on the Contract plans, the colour of the guide post shall be white.

a. Dimensions

Guide posts shall have the following dimensions:

1. Flat type

– Minimum post width shall be 75 mm of continuous flat surface with no curvature

for the entire length of the post. This will allow for ridges on the outer edges and back of post
intended for structural support.

2. Tubular type

– Post is tubular or round/circular in shape. This allows for a tubular post with a

minimum diameter of 75 mm or a tubular post with a minimum diameter of 50 mm with a flat
or flattened oval surface at least 75 mm wide and 305 mm long measured from the top for
mounting reflective sheeting.

3. Non-flat and non-tubular type

– Posts that do not fit into the two types indicated above,

including convex, w-shape, oval, and other designs. Post shall be wide enough to accept 75
mm wide reflective sheeting. Any curvature or rounding shall not significantly reduce the
brightness value of the reflective sheeting.

4. Surface mount guide post base

– Base for surface mount guide posts shall be approximately

200 mm in diameter with a maximum height of 50 mm.

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. Reflective sheeting shall

be mounted on the guide post as detailed in the Contract plans.

Sheeting shall remain in place during the life of the post.

c. Adhesive

Adhesives for surface mounted guide posts shall meet the requirements for flexible bituminous
adhesive or epoxy adhesive as defined in Articles 8.4.2.5 and 8.4.2.7.

d. Acceptance of Flexible Guide Posts

Flexible guide posts and reflective sheeting shall be approved by the Engineer prior to use on the
works. No rejected material shall be incorporated into the works.

Contractor

shall submit manufacturer’s certified test report, including test data developed by an

approved  testing  laboratory,  which  demonstrates  that  the  flexible  guide  post  complies  with  the
requirements of these  specifications. At the request of the  Engineer, the Contractor shall perform
tests  to  verify  compliance  with  these  specifications.  Results  of  the  testing  shall  be  reported  in
sufficient detail to enable the Engineer to evaluate compliance with these specifications.

1. Test Procedures (Laboratory Tests)

Sample size: 2 posts. Procedures shall be performed as follows:

i. Test for tensile strength and elongation per ASTM D638;

ii. Expose to 1,000 hours QUV weatherometer exposure (ASTM G154);

iii. Test again after exposure for tensile strength and elongation per ASTM D638;

iv. Prepare 6 bow tie specimens from the delineator post samples submitted for the purpose

of ultraviolet (UV) exposure;

v. Cycle specimens at 1,000 hours in a weatherometer in accordance with ASTM G154 (3

hr. 60C UV, 3 hr. 50C CON);

vi. Reserve 3 specimens as controls;

vii. Subject remaining 3 specimens to 1000 hours of UV exposure in the QUV

weatherometer.

Laboratory test data shall include the following:

i. Tensile strength and elongation of each specimen;

ii. Average tensile strength and elongation for control specimens;

iii. Average tensile strength and elongation weathered specimens.

iv. Percent change in tensile strength (based on average values);

v. Percent change in elongation (based on average values).

Acceptable specimens shall show no signs of delamination, distress, or discolouration.
Physical properties of tensile strength and rigidity shall be maintained within 80 % of the
unconditioned values.

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ii. Using the same test samples for all 10 hits, hit 4 delineators at an angle perpendicular

to the front of the post

a) 5 impacts at an ambient temperature of 0

C ±3

C (not required for project site impact

testing)

b) 5 impacts at an ambient temperature of 29

C ±3

iii. Using the same test samples for all 10 hits, hit 4 delineators at an angle of 25

clockwise

from the angle perpendicular to the front of the posts (hit on the bumper near the vehicle
headlight):

a) 5 impacts at an ambient temperature of 0

C ±3

C (not require for project site impact

testing)

b) 5 impacts at an ambient temperature of 29

C ±3

Each post shall be inspected after each impact and the following documented:

i. Any splits, cracks, breaks or other forms of deformation or distress;

ii. The percent list to vertical two minutes after each impact;

iii. The approximate percentage of the reflective area that is damaged after each impact to

an extent it no longer performs as intended;

iv. Any problems or comments associated with the installation and removal of the posts and

bases. Testing agent shall document any special equipment or techniques required for
installing or removing the posts and bases.

v. Any problems or comments associated with the performance of each ground mounted

flexible delineator post that would be of interest;

vi. Type of soil and impact surface.

A  minimum  of  50  %  of  the  reflective  sheeting  shall  be  retained  undamaged.  An  area  of
damage greater than 50 % is considered a failure. If the guide post leans more than 10o from
vertical it is considered a failure. Any cracking, other than surface cracking evident on only
one  face  of  the  post,  is  considered  a  failure.  Pullout  in  excess  of  75  mm  is  considered  a
failure. At least six of the guide posts must pass each criterion in the series of impacts to be
acceptable.

8.4.4.3

Construction Requirements

Flexible guide posts

shall be installed according to the manufacturer’s recommendations. At least

ten days prior to installation, the Contractor shall provide the Engineer

with the manufacturer’s

recommended installation procedures

, as part of the Contractor’s method statement for installation,

for prior approval by the Engineer.

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Shoulder Rumble Strips

8.4.5.1

Description

This work consists of constructing shoulder rumble strips by grinding hot mix asphalt. Rumble strip
grooves shall be cylindrical in configuration in the direction of the traffic flow and shall be placed as
shown on the Contract plans.

Work shall include cleanup and disposal of cuttings and other resultant debris. Patterns and
construction details for the centerline rumble strip and the shoulder rumble strips shall be as shown
on the Contract plans or as approved by the Engineer.

In cases where rumble strips are required to be applied in traveled lanes they shall be produced by
application of MMA road marking material to a nominal thickness of 5mm.

8.4.5.2

Equipment

Rumble strips shall be constructed with equipment specifically designed to remove asphalt concrete
material by means of grinding to a controlled line and grade without scarring the adjacent pavement.

Equipment shall be capable of removing the existing asphalt concrete to the dimensions and
tolerances specified in the Contract plans.

Equipment shall have a rotary type cutting head or series of cutting heads capable of grinding 1 or
more recesses as detailed in the Contract plans.

Equipment shall also be equipped with an approved guide that is clearly visible to the operator so
that proper alignment of the grooves will be obtained.

8.4.5.3

Construction Requirements

Rumble strips shall not be constructed in new asphalt concrete pavements for a minimum of three
days after placement, or 10 days after placement of new asphalt concrete pavements with

–polymer

modified bitumen.

Location and alignment shall be per the requirements shown on the Contract plans. Contractor shall
place a continuous control line to guide installation. Lateral deviation of the rumble strips shall not
exceed 25 mm in any 30 m interval. Difference between high and low surfaces shall not exceed 3
mm. Gaps in continuous rumble strips not shown on the Contract plans will be designated by the
Engineer. Accumulative error in the longitudinal spacing of the rumble strips and the gaps, when
required, shall not exceed ±5 %.

Rumble strips shall not be constructed on bridge decks, bridge approach slabs, or cement concrete
surfaces. In areas where monuments, drainage structures, induction loop lead-ins, pavement
markings or other features will not allow the rumble strips to be constructed as detailed, the rumble
strips shall be eliminated or relocated as approved by the Engineer.

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8.5.2

Definition of Terms

Brightness: A measurement of the ratio of the quantity of incident light per unit area returned to an
observer from a reflector. This measurement is expressed in units of candlepower per unit area per
lumens (mcd/m

/lux).

Divergence angle: Angle at the reflector between the observer's line of sight and the axis of the
incident light beam.

Entrance angle: Angle at the reflector between the axis of the incident light beam and the normal to
the reflective surface.

Intensity: A measurement of the ratio of the quantity of incident light per total area returned to an
observer from a reflector. This measurement is expressed in units of lumens/m

Legend: Characters, letters, numbers, and symbols including the border appearing on the
background on the sign face.

Sign face: That part of a sign panel facing toward oncoming traffic.

Sign panel: Structural part of a sign made of assembled units or sheet metal, plywood or fibreglass,
including reflectorized material applied to the face and bearing a legend, but excluding the supporting
posts or structure.

Sign supports: Posts, beams and structural tubes necessary to support the sign panels shall be as
indicated on the Contract plans.

8.5.3

Materials

Materials for the construction of permanent signing shall comply with the following sections:

a. Sign panels

– Article 8.5.3.4

1. Reflective sheeting

– Sub-article b of Article 8.5.3.4

2. Aluminium sign panels

– Sub-article 8.1.1.1e of Article 8.5.3.4

3. Plywood sign panels

– Paragraph 4 of Sub-article e of Article 8.5.3.4

4. Fiberglass signs

– Sub-article f of Article 8.5.3.4

b. Sign mounting

– Article 8.5.3.5

c. Sign posts

– Article 8.5.3.6

d. Sign foundations

– Article 8.5.3.7

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at the fabricator’s plant before shipment to the project,

and shall provide the Engineer a certificate of compliance that the fabricated signs meet all
requirements of the specifications. Engineer may also conduct inspections at the fabricators plant
and the Contractor shall provide the necessary provisions for these inspections.

Inspections shall not be made until all materials have been tested and approved.

A “FABRICATION APPROVED” decal shall be applied to back of all fabricated signs at the
fabricators plant, for signs that have been inspected and approved by the Contractor and/or
Engineer. Signs without this decal will not be installed on the project with the exception of double-
faced signs which do not receive decals or fabricator’s stickers.

8.5.3.3

Packaging and Marking

Materials shall be packaged and marked in accordance with Article 8.2.2.1.

Both ends of each box of reflective sheeting shall be clearly labeled with the sheeting type, color,
adhesive

type, manufacturer’s lot number, date of manufacture, and supplier’s name. Material safety

data sheets and technical bulletins for all materials shall be furnished to the Engineer with each
shipment.

All signs shall show the manufacturer’s name and date of manufacture on the back. In addition, the
width and height dimension, in cm, and the number of the sign as it appears in the Contract plans
shall be placed using 76 mm series C (see the MUTCD TR-511 for standard letters) black letters on
the back of destination, distance and large special signs.

Hand painted numbers is not permitted.

8.5.3.4

Sign Panels

Corner Radius

All regulatory and warning signs shall have rounded corners with the exception of stop signs.
Information and guide signs may have square cut corners. Borders for signs having square cut
corners shall have a corner radius approximately 1/8

of the lesser side dimension of the sign, up to

a maximum radius of 300 mm. For signs with rounded corners, the borders shall be concentric with
the rounded corners.

Reflective Sheeting

Reflective sheeting specified herein is intended for highway applications to assure optimum visibility
by day and at night when exposed to a light source and whether dry or totally wet by rain.

Contractor shall supply for the Engineer’s approval, the manufacturer’s certificate of compliance for
the reflective sheeting. Contractor shall submit a guarantee for replacement of any defective

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retroreflective sheeting referred to as “high-intensity” that is typically an unmetalized

microprismatic retroreflective element material.

3. Type IX : retroreflective sheeting typically manufactured as an unmetalized cube corner

microprismatic retrorereflective element material.

4. Type XI : retroreflective sheeting typically manufactured as an unmetalized cube corner

microprismatic retrorereflective element material.

Adhesive backing classes shall be as follows:

1. Class 1: Adhesive backing shall be pressure-sensitive and require no heat, solvent, or other

preparation for adhesion to smooth, clean surfaces.

2. Class 2: Adhesive backing shall have an adhesive that shall be activated by applying heat

and pressure to the material. Temperature necessary to form a durable permanent bond shall
be  a  minimum  of  66°  C.  Reflective  sheeting  materials  with  Class  2  adhesive  shall  be
repositionable  under  normal  shop  conditions  and  at  substrate  temperatures  up  to  38°  C
without damage to the sheeting.

Reflective sheeting materials with Class 2 adhesive may be perforated to facilitate removal
of air in heat-vacuum laminators, but the perforations must be of a size and frequency such
that they do not cause objectionable blemishes in the finished sign as determined by the
Engineer.

3. Class 3: This adhesive backing shall be a positionable low-tack pressure-sensitive adhesive

that requires no heat, solvent, or other preparation for adhesion to smooth, clean surfaces.
Reflective sheeting materials with Class 3 adhesive shall be repositionable up to a
temperature of 38° C without damage to the sheeting.

4. Class 4: Adhesive backing shall be a low-temperature pressure-sensitive adhesive that

permits sheeting applications down to

–7° C without the aid of heat, solvent, or other

preparation for adhesion to smooth, dry, and clean surfaces.

Chemical activators shall not be used to activate Class 2 adhesive.

Reflective sheeting shall meet the requirements of these specifications and of ASTM D 4956 as
defined for:

1. Adhesive

2. Liner removal

3. Daytime colour

4. Nighttime colour

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13. Processing

14. Identification

All sheeting shall be weather resistant and have a protected pre-coated adhesive backing.

Sampling and Testing

For the purpose of testing and qualification, sample size for reflective sheeting shall be a full width
by 1 m long sample selected at random to represent the entire sheet, roll, or lot. Package marking
shall include the ASTM sheeting type and ASTM backing class designations.

Wet Performance

Wet performance measurements on unweathered sheeting shall be conducted in accordance with
one of the following methods:

•

Standard rainfall test specified in Federal Specification LS 300C and the brightness of the

reflective sheeting totally wet by rain shall not be less than 90 % of the dry values.

•

Samples shall be submerged in a tank of clean water (22° C) for 5 min. Reflex-reflective

performance of the sheeting shall be viewed in a darkened room by reflected light through
the surface of the water or through a transparent plane surface of the tank parallel to the
sample surface. Light source shall be such as a hand flashlight held close to the eye. Wet
sheeting shall show no loss of reflective performance as compared to dry material.

1. Specular Gloss

Reflective sheeting for road signs shall have an 85

specular gloss of not less than 50 for

when tested in accordance with ASTM D523.

2. Flexibility

Reflective sheeting for signs, with the liner removed and conditioned for 24 hr at 22o C and
50 % relative humidity, shall be sufficiently flexible to show no cracking when slowly bent, in
one second's time, around a 3.20 mm mandrel with adhesive contacting the mandrel. Note:
For ease of testing, spread talcum powder on adhesive to prevent sticking to the mandrel.

3. Impact Resistance

Reflective sheeting materials, applied according to the manufacturer's recommendations to
a cleaned, etched aluminium panel of alloy 6061-T6 (ASTM B308M), 1.0 mm by 76 mm by
127 mm and conditioned for 24 hr at 23° C and 50 % relative humidity, shall show no cracking
when the face of the panel is subjected to an impact of a 0.9 kg weight with a 16 mm rounded
tip dropped from a 1.13 Nm setting on a Gardner Variable Impact Tester, 1G-1120 (ASTM
D2794).

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Colours shall be as specified herein or as indicated on the Contract plans. Completed letters,
numerals, and other units shall be formed to provide continuous stroke width with smooth
edges and shall present a flat surface free of warp, blisters, wrinkles, burrs, and splinters.
Units of the sign message of the type indicated on  the Contract plans  such as the letters,
numerals,  symbols,  borders  and  other  features  of  the  sign  message  shall  be  cut  from
reflective sheeting of the colour and type specified on the Contract plans and applied to the
reflective sheeting of the sign field in accordance with the instructions of the manufacturer of
the reflective sheeting.

7. Process Colours

Transparent and opaque process colours used in silk screening sign messages shall be as
recommended by the manufacturer. When properly applied, process colours shall perform
satisfactorily for the expected life of the sheeting.

Applied colours shall present a smooth surface, free from foreign material, and all messages
and borders shall be clear and sharp. Sheeting shall conform to the retroreflective minimum
values and colour limits established for its type and colour without regard to whether the
colour is integral to the sheeting or achieved by applying transparent colours to silver/white
sheeting.

There shall be no variations in colour, and overlapping of colours will not be permitted.

Properly applied and cured process colours shall exhibit no blistering, bubbling, or loss of
colour or transparency when cleaned with a mild non-abrasive detergent solution. Minor loss
of colour may be detected when solvents such as kerosene, mineral spirits, heptane, or
naphtha are used to clean severely contaminated signs; e.g., paint vandalism. However, the
colours shall not blister, bubble, peel, or be easily removed.

Aluminum Sign Panels

Extruded aluminum channels shall be used for all guide signs and shall be as indicated on the
Contract plans.

Basis for acceptance of aluminum sign blanks and panels shall be a mill test certificate from the
aluminum manufacturer attesting to the correct alloy and temper of the metal supplied. At the option
of the Engineer, laboratory tests may also be performed to confirm metallurgical data. If the panel
consists of more than one part, all panel parts shall be of the same material, sheeting, paint, etc.

Traffic sign panel blanks for "warning and regulatory signs" shall be of sheet aluminum with reflective
sheeting all as specified herein and as indicated on the Contract plans. Sheet aluminum sign blanks

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aluminum as specified herein and as indicated on the Contract plans.

Surface area shall be determined by calculating the area of the smallest rectangle that will
circumscribe an individual sign, except in the case of a triangular sign. The area of a triangular sign
shall be the net triangular area.

Aluminum sign blanks shall be free from laminations, blisters, slivers, open seams, pits from heavy
rolled-in scale, ragged edges, holes, turned down corners, or other defects which may affect
appearance or use for the intended purpose. All blanks shall be as nearly uniform in thickness as is
practicable and shall be commercially flat. All shearing, cutting and punching shall be done prior to
preparing the sign blanks for the application of reflective material.

Sheared edges of all sign blanks shall be straight and free from tears and raggedness and distortion
of the metal. All punched or drilled holes shall be round, free from tears and raggedness.

Sheet aluminum signs shall be constructed of material conforming to ASTM B209 alloy 6061-T6 or
alloy 5052-H36 or H38. Alloy 5005-H34 may be used for sign overlays.

After the sheeting has been fabricated, the sheeting for all multiple panel signs shall be degreased,
etched by immersion for a minimum of 5 min in a caustic etch solution at 49

C, followed, in order,

by a water rinse, de-oxidation, water rinse, hot water rinse, and drying. Etching process shall produce
a dull aluminum finish on both sides of the panel which will last the life of the sign.

Treated panel surface shall be compatible with the opaque and reflective sheeting to be applied in
accordance with the specifications. Contractor may use an Alodine 1200 application for single panel
signs in lieu of the above treatment.

Aluminum signs shall be constructed as shown on the Contract plans or as required in the Particular
Specifications. If not otherwise defined, signs shall be constructed as per the following guidelines:

1. Aluminum signs over 3.7 m wide by 1.5 m high shall be comprised of vertical panels in

increments of 0.5, 1.0, or 1.5 m wide.

2. No more than one 0.5 m and/or 1.0 m panel may be used per sign. Contractor shall use the

widest panels possible.

3. All parts necessary for assembly shall be constructed of aluminum, galvanized, or stainless

steel or as shown on the Contract plans.

4. Minimum sheet thickness shall be as follows:

Table 8-29: Minimum thickness for maximum horizontal dimension sheet aluminum

Horizontal dimension

Minimum sheet aluminum thickness

Overlay panels

1.27 mm

Up to 50 cm

1.60 mm

50 cm to 91 cm, inclusive

2.03 mm

Over 91 cm (Permanent Signs)

3.18 mm

Side dimension for a diamond shaped warning sign is considered to be the maximum horizontal
dimension.

Before placing aluminum in contact with untreated steel, the steel surfaces shall be protected by
proper cleaning and painting with one coat of zinc primer A-9-73 (Mil-P-21035) and two coats of
aluminum paint with the following formula:

1. Aluminum paste (ASTM D962, Type 2 Class B): 0.91 kg.

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ii. Preliminary cleaning shall be followed by etching. This shall consist of immersion for at least

3 min in a 6 to 8 % solution of phosphoric acid at 40° C. Blank panels shall then be rinsed
in a spray of cold water, followed by immersion for one minute in circulating hot water at
80°C. They shall then be dried by forced warm air or infrared lamps.

iii. If total immersion is impossible because of the length of the panels, 6 to 8 % phosphoric

acid at 40° C may be applied to the surface by swabbing, brushing, or spraying, allowed to
remain for 5 min, and then removed by a cold water rinse, followed by drying with warm or
forced air.

iv. Metal shall not be handled except by a device or clean canvas gloves between all cleaning

and etching operations and the application of reflective sheeting. There shall be no
opportunity for the metal to come in contact with greases, oils, or other contamination prior
to the application of reflective sheeting.

v. If a chemical conversion coating is used, the coating shall be light, tight, and free from all

powdery residue.

When the reflective sheeting is applied to individual extruded aluminium channels, the
channels shall be assembled after the background sheeting has aged for 48 hr at 24° C.

Channels shall be bolted together using the panel bolt assembly indicated on the Contract
plans which shall be on 600 mm maximum centers. Nuts on panel bolts shall be drawn tight.

Side-trim molding shall be installed on both vertical edges of the extruded aluminium panels
after the clear finish has dried. Any damage to the clear film shall be repaired and the contact
between the molding and the reflective sheeting shall be edge sealed as recommended by
the sheeting manufacturer.

2. Application of Background Sheeting

Reflective sheeting shall be applied in the manner specified by the sheeting manufacturer.
Applied sign face shall not have bubbles, wrinkles, or foreign material beneath the reflective
sheeting.

Reflective sheeting shall be applied to all sign faces by an approved vacuum or continuous
roll applicator. The background reflective sheeting shall adhere over and around the sides of
all  panels  to  a  minimum  distance  of  2  mm  beyond  the  edges.  All  edges  and  splices  of
reflective  sheeting  signs  shall  be  coated  with  an  edge  sealer  when  recommended  by  the
manufacturer  of  the  reflectorized  sheeting.  Side-trim  molding  shall  be  installed  on  both
vertical edges of the extruded aluminum panels after the clear finish has dried. Any damage

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be applied to sheet panels capable of being inserted in the approved vacuum applicator.
Legend for signs which will have the legend screened onto a reflective sheeting with heat
activated adhesive shall be added to the background before the sheeting is applied to the
panel.

When vacuum applied, the pre-coated adhesive on the back of the reflective sheeting shall
be activated by a minimum temperature of 85° C and with a minimum vacuum pressure of
635 mm of mercury. This operation shall be in effect for a minimum of 5 min. After aging for
48 hr at 24° C the adhesive shall form a bond equal to or greater than the strength of the
reflective sheeting.

Splicing of reflective sheeting shall be minimized as much as possible, and generally shall
not be permitted on signs or panels with dimensions up to and including 1.2 m in height or
width. Widest size of material available shall be used. When sheeting joints are required, they
shall be lap-jointed with the top sheet overlapping the bottom sheet by no less than 5 mm.

Fabricator shall endeavor to use the least number of seams possible with the horizontal lap
preferable. Roller applied or reverse screened sheeting may be butt-jointed with joint gap not
to exceed 1.0 mm. No splice shall fall within 50 mm of the edge of the panel. No borders shall
be spliced other than the splice of the tangent border to the corner radius

Sign faces comprising two or more pieces of reflective sheeting must be carefully matched
for colour at the time of sign fabrication to provide uniform appearance and brilliance, both
day and night. Noncompliance may result in non-uniform shading and an undesirable
contrast between adjacent width of applied sheeting, which will not be acceptable.

Damaged reflective sheeting due to poor workmanship or defective material shall be rejected,
and shall be replaced by the Contractor at the Contractor

’s ‘expense.

When reflective sheeting is applied to individual extruded aluminum channels, the channels
shall be assembled after the background sheeting has aged for 48 hr at 24° C.

Channels shall be bolted together using the panel bolt assembly indicated on the Contract
plans which shall be on 600 mm maximum centers. Nuts on panel bolts shall be drawn tight.

3. Finishing

Legend, borders, and sheeting cuts at intersecting panel edges shall be finished with a clear
coating approved by the sheeting manufacturer. After message or border application, the
complete sign including edges shall be finished with a clear coating approved by the sheeting
manufacturer.

4. Plywood Sign Panels

Plywood  sign  panels  shall  only  be  used  for  temporary  construction  or  construction
management  type  scenarios  unless  otherwise  shown  on  the  Contract  plans.  Plywood  for
highway  signs  shall  be  smooth,  weather-resistant,  of  one-piece  construction,  and  free  of
either scarf or finger joints. Plywood will bear legible grade markings of APA, The Engineered
Wood  Association  or  the  Canadian  Council  of  Forest  Industries  (COFI).  Colour  shall  be
natural or as approved by the Engineer. Plywood shall meet the following criteria:

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inner ply and shall not exceed 4.8 mm for average of all gaps in a panel. Inner ply gaps
shall not exceed four core gaps and edge splits per 2.4 m of cross-band layer.

Unless otherwise specified, overlay sheets on both sides of the plywood panel shall be used
of high-density material that meets or exceeds the requirements of the latest revision of U.S.
Product Standard PS-1 or Canadian Standard CSA 0121.

Hard, smooth, unbroken finished surfaces that do not require further finishing by paint or
varnish shall be provided for the overlay sheet.

For the complete panel, plywood for sign panels that do not deviate from a plane surface by
more than 50 mm at any point shall be provided. Panels shall be free of dents, bruises,
scratches, veneer or overlay delaminations, paint stains, or other damage that would interfere
with use of the panel in sign construction.

Fiberglass Reinforced Plastic Signs

Fiberglass reinforced plastic signs and overlay panels shall be constructed of a fiberglass reinforced
thermosetting polyester laminate. Sign panel shall be acrylic modified and UV stabilized for outdoor
weathering ability. Sign panel shall be stabilized to prevent the release of migrating constituents
(such as solvents, monomers, etc.) over the expected life of the sign. Sign panel shall contain no
residue release agents on the surface of the laminate so neither migrating constituents or release
agents will be present in amounts which will interfere with any subsequent bonding operations.

Sign panel shall not contain visible cracks, pinholes, foreign inclusions, or surface wrinkles that would
affect implied performance, alter the specific dimensions of the panel, or otherwise affect its
serviceability. Sign panel surface shall be wiped clean with a slightly water dampened cloth before
applying reflective sheeting.

1. Mechanical Properties

All mechanical properties are stated as minimum requirements. Mechanical properties are
measured in both the line direction of the panel and at 90o to the line as noted in the
appropriate ASTM test referenced.

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0.703 kg/cm

× 103

ASTM D638

Tensile Modulus

0.084 kg/cm

× 106

ASTM D638

Flexural Strength

1.406 kg/cm

× 103

ASTM D790

Flexural Modulus

0.084 kg/cm

× 106

ASTM D790

Compression Strength

2.25 kg/cm

× 103

ASTM D695

Compression Modulus

0.098 kg/cm

× 106

ASTM D695

Punch Shear

0.914 kg/cm

× 103

ASTM D732

2. Physical Properties

Sign panels are to be 3.43 mm thick. Overlay panels are to be 1.91 mm thick. Panel thickness
tolerance shall be plus or minus 0.127 mm. Panel tolerance on nominal length and width
shall be plus or minus 3.18 mm for dimensions of 3.66 m or less and shall be within 3.18 mm
of square per 3.66 m length when measured in accordance with ASTM D3841.

Panels  shall  be manufactured  with  smooth  surfaces  on  both top  and  bottom  of  the  panel.
Panel  flatness  of  a  750  mm  x  750  mm  panel  shall  be  measured  by  hanging  the  panel
diagonally  in  suspension.  Maximum  deflection  measured  diagonally,  parallel  and
perpendicular to the panel by lines drawn through the center of the panel, shall not exceed
12.7 mm. Panel shall then be hung diagonally in suspension in an oven for 48 hr at 82o C.
Maximum deflection shall again be measured as previously noted and shall not exceed 12.7
mm. All measurements shall be made when panels are at ambient temperature.

Panels shall be pigmented to a visually uniform gray color within the Munsell range of N.7.5/G
to N.8.5/G.

Panels shall be classified as to a minimum Grade II (weather resistant) panel as specified in
ASTM D3841 following 3,000 plus or minus 100 hr weatherometer test.

Panels shall contain additives designed to be less responsive to fire ignition and flame
propagation. As such, the extent of burning shall not exceed 25 mm when tested in
accordance with ASTM D635.

Panels shall resist the impact energy of 27.12 J applied with a hemispherical tipped object
25 mm in diameter.

Panels’ thermal stability for strength and impact resistance qualities shall not be appreciably
affected over a temperature range of -54º C to 100° C.

8.5.3.5

Sign Mounting Materials

Structural High Strength Steel

Structural high strength steel shall be high yield strength, quenched and tempered structural steel
conforming to AASHTO M 270, Grades 70W, 100, or 100W as specified in the Contract plans and
Chapter 23, Steel Structures, of these standard specifications. All structural steel shall be
assembled, formed and fabricated per the requirements of Chapter 23, Steel Structures.

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Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 1 - ROADS, Second Edition 2020) - page 35