Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10)

Cribbing 9-27

9-27 Cribbing

9-27.1 Vacant
9-27.2 Vacant
9-27.3

Gabion Cribbing

9-27.3(1) Gabion Fabric

Gabions may be fabricated from either hexagonal twisted wire or from welded wire.
Only one type of wire and protective coating shall be used throughout a structure.

Baskets shall be furnished in the required dimensions with a dimensional tolerance of plus
or minus 5 percent.

Wire for construction of gabions shall be either galvanized steel wire conforming to
ASTM A641, Class 3, Soft Temper, or aluminized steel wire conforming to ASTM A809,
Soft Temper. The wire shall have a minimum tensile strength of 60,000 psi when tested in
accordance with ASTM A370.

9-27.3(2) Gabion Baskets

Gabion baskets 1 foot or greater in the vertical dimension shall have openings with
nominal dimensions not to exceed 4½ inches and the maximum area of any opening shall
not exceed 10 square inches.
1. Hexagonal Twisted Wire

a. Wire for galvanized or aluminized hexagonal twisted welded wire shall be

nominal sized 0.120 inch galvanized steel wire or aluminized steel wire.

b. Hexagonal twisted wire shall be formed from galvanized or aluminized wire in a

uniform hexagonal pattern with nonraveling double twist. The perimeter edges
of each panel shall be tied to a selvage wire of the same composition as the
panel body and have a minimum diameter of 0.150 inch so that the selvage is at
least the same strength as the body of the panel.

2. Welded Wire

a. Welded wire shall be fabricated from galvanized steel wire having a diameter of

0.106 inch. Wire shall be galvanized prior to fabrication.

b. Welded wire shall be formed in a uniform square pattern with openings

3 by 3 inches with a resistance weld at each connection in accordance with
ASTM A1064.

c. If required, a PVC coating shall be fusion bonded onto the welded wire mesh to

provide a nominal coating thickness of 0.0216 inch per side with a minimum of
0.0150 inch.

Page 9-172

3. PVC Coating (For Welded Wire Only)

Acceptance of PVC coating material shall be by certified test reports of an
independent laboratory. The initial properties of PVC coating material shall have a
demonstrated ability to conform to the following requirements:
a. Specific Gravity – In the range of 1.2 to 1.4, when tested according to ASTM

D792.

b. Tensile Strength – Not less than 2,275 psi, when tested according to ASTM

D638.

c. Modulus of Elasticity – Not less than 1,980 psi at 100 Strain, when testing

according to ASTM D638.

d. Hardness – Shore “A” not less than 75 when tested according to ASTM D2240.
e. Brittleness Temperature – Not higher than 15ºF when tested according to

ASTM D746.

Resistance to Abrasion – The percentage of the mass loss shall be less than
12 percent when tested according to ASTM D1242, Method B at 200 cycles,
CSI-A Abrader Tape, 80 Grit.

g. Salt Spray Exposure and Ultraviolet Light Exposure – The PVC shall show no

effect after 3,000 hours of salt spray exposure according to ASTM B117. The
PVC shall show no effect of exposure to ultraviolet light with test exposure
of 3,000 hours using apparatus Type E and 63°C, when tested according to
Practice D1499 and Practice G 23. After the salt spray test and exposure to
ultraviolet light as specified above, the PVC coating shall not show cracks,
blister, split, nor show a noticeable change of color. In addition, the specific
gravity, tensile strength, modulus of elasticity, and resistance to abrasion
shall not change more than 6, 25, 25, and 10 percent respectively from their
initial values.

9-27.3(3) Gabion Mattresses

Gabion baskets less than 1 foot in the vertical dimension shall have openings with
nominal dimensions not to exceed 3.3 inches, and the maximum area of any opening shall
not exceed 6 square inches.
1. Hexagonal Twisted Wire

a. Wire for galvanized or aluminized hexagonal twisted wire shall be nominal sized

0.086 inch galvanized steel wire or aluminized steel wire.

b. Hexagonal twisted wire shall be formed from galvanized or aluminized wire in

a uniform hexagonal pattern with nonraveling double twisted. The perimeter
edges of each panel shall be tied to a selvage wire of the same composition
as the panel body and have a minimum diameter of 0.1062 inch so that the
selvage is at least the same strength as the body of the panel.

Cribbing 9-27

2. Welded Wire

a. Welded wire shall be fabricated from galvanized steel wire having a diameter of

0.080 inch. Wire shall be galvanized prior to fabrication.

b. Welded wire shall be formed in a uniform rectangular pattern with openings

1½ by 3 inches with a resistance weld at each connection in accordance with
ASTM A1064.

c. If required, a PVC coating shall be fusion bonded onto the welded wire to

provide a nominal coating thickness of 0.0216 inch per side with a minimum of
0.0150 inch. The PVC coating shall be in conformance with

Section 9-27.3(2)

9-27.3(4) Fasteners for Basket Assembly

The lacing wire shall be a nominal sized 0.0866 inch galvanized steel wire or aluminized
steel wire. Lacing wire shall have the same coating as the basket.

Spiral binders, if used for joining welded wire panels shall be formed from 0.106 inch
nominal diameter steel wire with a 3-inch pitch having the same Specifications and
coating as the welded wire. Lacing wire may be used in lieu of spiral binders.

Alternate fasteners for basket assembly shall remain closed when subjected to a
600 pound tensile force when confining the maximum number of wires to be confined.
Installation procedures and test results for alternate fasteners shall be submitted
for approval.

Internal connecting wires shall be the same as required for lacing wire. Alternate stiffeners
acceptable to the gabion manufacturer may be used.

9-27.3(5) Nonraveling Construction

The gabion wire shall be fabricated in a manner to be nonraveling. This is defined as the
ability to resist pulling apart at any of the connections forming the panel when a single
strand in a section of panel is cut.

9-27.3(6) Stone

Stone for filling gabions shall have a Degradation Factor of at least 30. The stone shall be
dense enough to pass the unit weight test described in

Section 8-24.3(3)F

. Stone shall

meet the following requirements for gradation:

Sieve Size

Percent Passing

8″

100

6″

75-90

4″

0-10

% Fracture

75 min.

All percentages are by weight.

Page 9-174

Signing Materials and Fabrication

9-28

Signing Materials and Fabrication

9-28.1 General

Unless noted otherwise in the Plans, permanent signs shall be constructed of sheet
aluminum. Permanent signs which measure 36 inches or less on a side and are to be
mounted on a single post may be constructed of single 0.135-inch fiberglass reinforced
plastic panels. Sign overlay panels may be either 0.050-inch aluminum or 0.075-inch
fiberglass reinforced plastic panels. All signs, except internally illuminated signs, shall be
reflectorized.

See ASTM D4956 for reflective sheeting type designations. Standard control signs and
guide sign borders, letters, numerals, symbols, shields, and arrows shall be in accordance
with the WSDOT

Sign Fabrication Manual

M 55-05.

All STOP, YIELD, DO NOT ENTER, WRONG WAY, FREEWAY ENTRANCE, and HIGHWAY
ENTRANCE signs shall be constructed entirely of Type III or IV reflective sheeting. All
M series, I series, and D-10 series signs and all signs with blue or brown backgrounds
shall be constructed entirely of Type II reflective sheeting unless otherwise specified.
Background reflective sheeting for all other signs shall be as noted in the Plans. Sign
legends for all other signs shall be constructed of Type III or IV reflective sheeting. Sign
legends include: borders, letters, numerals, symbols, shields, and arrows. Reflective legend
sheeting types shall not be mixed on individual signs.

9-28.2

Manufacturer’s Identification and Date

All signs shall show the manufacturer’s name and date of manufacture on the back. In
addition, the width and height dimension, in inches, the Contract number, and the number
of the sign as it appears in the Plans shall be placed using 3-inch series C black letters
on the back of destination, distance, and large special signs. Hand painted numbers are
not permitted.

9-28.3

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 ⅛ of the lesser side dimension
of the sign up to a maximum radius of 12 inches. For signs with rounded corners, the
borders shall be concentric with the rounded corners.

Signing Materials and Fabrication

9-28

9-28.4

Extruded Windbeams and “Z” Bar

All multiple post and multiple panel signs shall be constructed and installed with
horizontal extruded windbeams and “Z” bar, when required, as shown in the Plans or
the

Standard Plans

. All bolt and rivet heads visible on the sign face shall be anodized or

painted to match the sign area immediately surrounding the bolt or rivet head. Extruded
windbeams and “Z” bar shall be accepted on the basis of a certificate of compliance from
the manufacturer. Materials shall be as designated in

Section 9-28.11

9-28.5

Letter and Spacing Formula

Letter and arrow sizes shall be as specified in the Plans. Spacing formulas shall be those
furnished by the manufacturer of the letters.

9-28.6

Destination Sign Messages

Destination sign messages, borders, shields, and symbols shall be direct applied
unless otherwise noted in the sign plans. All message components shall be one
piece construction unless the least dimension exceeds available sheeting widths. All
components shall have smooth, sharp cut edges. Components which are torn, wrinkled,
or exhibit poor workmanship, will not be permitted.

9-28.7

Process Colors

Transparent and opaque process colors used in silk screening sign messages shall be as
recommended by the manufacturer. When properly applied, process colors shall perform
satisfactorily for the expected life of the sheeting. Applied colors 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 color limits established
for its type and color without regard to whether the color is integral to the sheeting
or achieved by applying transparent colors to silver/white sheeting. There shall be no
variations in color, and overlapping of colors will not be permitted.

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

Page 9-176

Signing Materials and Fabrication

9-28.8

Sheet Aluminum Signs

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. The
Contractor shall provide a mill test certificate from the aluminum manufacturer attesting
to the correct alloy and temper of the metal supplied, when requested by the Engineer.
After the sheeting has been fabricated, the surface of each panel shall be protected from
corrosion. The corrosion protection shall meet the requirements of ASTM B449 Class II
Specification for Chromates on Aluminum. Aluminum signs over 12 feet wide by 5 feet
high shall be comprised of vertical panels in increments of 2, 3, or 4 feet wide. No more
than one 2-foot and/or 3-foot panel may be used per sign. The Contractor shall use the
widest panels possible. All parts necessary for assembly shall be constructed of aluminum,
galvanized steel, or stainless steel in accordance with the Plans. Sheet thickness shall be
as follows:

Maximum Horizontal Dimension

Sheet Aluminum Thickness

Overlay panels

0.050 inch

Up to 20 inches

0.063 inch

20 to 36 inches, inclusive

0.080 inch

Over 36 inches (Permanent Signs)

0.125 inch

The 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 paint conforming to

Section

9-08.1(2)B

and two coats of aluminum paint.

Metal shall be handled by device or clean canvas gloves between all cleaning and etching
operations and the application of reflective sheeting.

9-28.9

Fiberglass Reinforced Plastic Signs

Fiberglass reinforced plastic signs and overlay panels shall be constructed of a fiberglass
reinforced thermoset polyester laminate. The sign panel shall be acrylic modified and UV
stabilized for outdoor weathering ability.

The sign panel shall be stabilized to prevent the release of migrating constituents (such as
solvents, monomers, etc.) over the expected life of the sign. The 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.

The 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.

The sign panel surface shall be wiped clean with a slightly water dampened cloth before
applying reflective sheeting.

Signing Materials and Fabrication

9-28

9-28.9(1) Mechanical Properties

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

Mechanical Property

Ave. Min. Requirement

ASTM Test

Tensile Strength

10.0 psi × 10

D638

Tensile Modulus

1.2 psi × 10

D638

Flexural Strength

20.0 psi × 10

D790

Flexural Modulus

1.2 psi × 10

D790

Compression Strength

32.0 psi × 10

D695

Compression Modulus

1.4 psi × 10

D695

Punch Shear

12.0 psi × 10

D732

9-28.9(2) Physical Properties

Sign Panels are to be 0.135 inch thick. Overlay panels are to be 0.075 inch thick. Panel
thickness tolerance shall be plus or minus 0.005 inch. Panel tolerance on nominal length
and width shall be plus or minus ⅛ inch for dimensions of 12 feet or less and shall be
within ⅛ inch of square per 12 feet of 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 30 by 30-inch panel shall be measured by hanging the panel diagonally
in suspension. The maximum deflection measured diagonally, parallel and perpendicular
to the panel by lines drawn through the center of the panel, shall not exceed ½ inch. The
panel shall then be hung diagonally in suspension in an oven for 48 hours at 180°F. The
maximum deflection shall again be measured as previously noted and shall not exceed
½ inch. All measurements shall be made when panels are at ambient temperature.

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

Panels shall have a maximum coefficient of lineal thermal expansion of 1.8 × 10

-5

in/in/°F.

when tested in accordance with ASTM D696.

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 hour 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 1.0 inch when tested in
accordance with ASTM D635.

Panels shall resist the impact energy of 20 foot-pounds applied with a hemispherical
tipped object 1 inch in diameter.

Page 9-178

Signing Materials and Fabrication

The panels thermal stability for strength and impact resistance qualities shall not be
appreciably affected over a temperature range of -65ºF to 212°F.

Fiberglass reinforced plastic panels for signs shall be accepted on the basis of a certificate
of compliance from the manufacturer as outlined in

Section 1-06.3

9-28.10

Digital Printing

Transparent and opaque durable inks used in digital printed sign messages shall be as
recommended by the manufacturer. When properly applied, digital printed colors shall
have a warranty life of the base retroreflective sign sheeting. Digital applied colors shall
present a smooth surface, free from foreign material, and all messages and borders shall
be clear and sharp. Digital printed signs shall conform to 70% of the retroreflective
minimum values established for its type and color. Digitally printed signs shall meet the
daytime color and luminance, and nighttime color requirements of ASTM D 4956. No
variations in color or overlapping of colors will be permitted. Digital printed permanent
traffic signs shall have an integrated engineered match component clear protective
overlay recommended by the sheeting manufacturer applied to the entire face of the sign.
On Temporary construction/maintenance signs printed with black ink only, the protective
overlay film is optional, as long as the finished sign has a warranty of a minimum of three
years from sign sheeting manufacturer.

All digital printed traffic control signs shall be an integrated engineered match
component system. The integrated engineered match component system shall consist
of retroreflective sheeting, durable ink(s), and clear overlay film all from the same
manufacturer applied to aluminum substrate conforming to

Section 9-28.8

The sign fabricator shall use an approved integrated engineered match component system
as listed on the Qualified Products List (QPL). Each approved digital printer shall only use
the compatible retroreflective sign sheeting manufacturer’s engineered match component
system products.

Each retroreflective sign sheeting manufacturer/integrated engineered match component
system listed on the QPL shall certify a department approved sign fabricator is approved
to operate their compatible digital printer. The sign fabricator shall re-certify annually
with the retroreflective sign manufacturer to ensure their digital printer is still meeting
manufacturer’s specifications for traffic control signs. Documentation of each re-
certification shall be submitted to the QPL Engineer annually.

Signing Materials and Fabrication

9-28

9-28.11 Hardware

Bolts, nuts, locknuts, and washers shall be of the same material for each attachment.
Bolts, nuts, locknuts, and washers for signs mounted on overhead sign structures (i.e., sign
bridges, cantilevers sign structures, and bridge mounted sign brackets) shall be stainless
steel only.

Hardware

Specification

Bolts

ASTM F468 2024-T4 Aluminum

ASTM A307 Steel

ASTM F593 Group 1, Condition A Stainless Steel, or ASTM A193,

Grade B8, Class 1 Stainless Steel

U-bolts

ASTM A276 Type 304 Stainless Steel

Washers

ASTM B209 2024-T4 Aluminum

ASTM F844 Steel

ANSI B18.22.1 Stainless Steel Alloy 304

Nuts

ASTM F467 2024-T4 Aluminum

ASTM A563 Grade A Steel

ASTM F594 Group 1 Stainless Steel, or

ASTM A194 Grade 8 or 8A Stainless Steel

Locknuts

(with nylon insert unless

otherwise in the Plans)

ASTM F467 2024-T4 Aluminum

ASTM A563 Grade A Steel

ASTM F594 Group 1 Stainless Steel, or noted

ASTM A194 Grade 8 or 8A Stainless Steel

Rivets

ASTM B316 5052 Aluminum Alloy

ASTM B316 5056 Aluminum Alloy

Post Clips

ASTM B179 356-T6 Aluminum

Windbeams

ASTM B221 6061-T6 Aluminum

Angle and “Z” Bar

ASTM B221 6061-T6 Aluminum

ASTM A36 or ASTM A992 Steel

Strap and Mounting Bracket

ASTM A666, Type 201 Stainless Steel

All steel parts shall be galvanized in accordance with AASHTO M111. Steel bolts and
related connecting hardware shall be galvanized in accordance with ASTM F 2329.

9-28.12

Reflective Sheeting

Type I and Type II reflective sheeting shall consist of spherical lens elements embedded
within a transparent plastic having a smooth, flat outer surface. Type III and Type IV
reflective sheeting shall consist of spherical or prismatic lens elements adhered to a
synthetic resin and encapsulated by a flexible, transparent, weatherproof plastic having a
smooth outer surface. Type V reflective sheeting shall consist of metallized microprismatic
lens bonded to a flexible, smooth-surfaced, weather resistant polymeric film. Type VI
reflective sheeting shall consist of unmetallized microprismatic lens formed on a flexible
vinyl material. Type VII, VIII, IX and Type X Fluorescent Orange reflective sheeting shall
consist of unmetallized microprismatic lens formed in a synthetic resin and encapsulated
by a flexible, transparent, weatherproof plastic having a smooth outer surface. All sheeting
shall be weather resistant and have a protected pre-coated adhesive backing. Type II

Page 9-180

Signing Materials and Fabrication

reflective sheeting shall contain an identifying marking, such as a water mark, which is
visible after sheeting application. The marking shall not adversely affect the performance
or life of the sheeting.

The reflective sheeting shall have the following minimum coefficient of retroreflection
values at 0.2 degrees and 0.5 degrees observation angle expressed as average candelas
per foot-candle, per square foot of material. Measurements shall be conducted in
accordance with ASTM E810.

Type I Glass Bead Retroreflective Element Material

Obs.

Angle

Entrance

Angle

Silver

White

Yellow

Orange

Green

Red

Blue

Brown

0.2°

-4°

9.0

4.0

1.0

0.2°

+30°

7.0

3.5

6.0

1.7

0.3

0.5°

-4°

4.5

7.5

2.0

0.3

0.5°

+30°

4.0

2.2

3.0

0.8

0.2

Type II Glass Bead Retroreflective Element Material

Obs.

Angle

Entrance

Angle

White

Yellow

Orange

Green

Red

Blue

Brown

0.2°

-4°

140

100

5.0

0.2°

+30°

4.0

2.0

0.5°

-4°

9.0

3.0

2.0

0.5°

+30°

6.0

2.0

1.0

Type III Glass Bead Retroreflective Element Material

Obs.

Angle

Entrance

Angle

Silver

White

Yellow

Orange

Green

Red

Blue

Brown

0.2°

-4°

250

170

100

0.2°

+30°

150

100

8.5

0.5°

-4°

7.5

5.0

0.5°

+30°

5.0

3.5

Type IV Micro Prismatic Retroreflective Element Material

Obs.

Angle

Entrance

Angle

White

Yellow

Green

Red

Blue

Brown

0.2°

-4°

250

170

7.0

0.2°

+30°

5.0

2.0

0.5°

-4°

135

100

4.0

0.5°

+30°

6.5

3.5

1.4

Signing Materials and Fabrication

9-28

Type VI Vinyl Micro Prismatic Retroreflective Element Material

Obs.

Angle

Entrance

Angle

White

Yellow

Orange

Green

Red

Blue

0.2°

-0.4°

250

170

0.2°

+30°

7.6

0.5°

-0.4°

200

136

0.5°

+30°

7.2

8.4

4.8

Type VII Micro Prismatic Retroreflective Element Material

Obs.

Angle

Entrance

Angle

White

Yellow

Orange

Green

Red

Blue

0.2°

-0.4°

750

560

280

150

0.2°

+30°

430

320

160

0.5°

-0.4°

240

180

0.5°

+30°

135

100

6.0

Type VIII Micro Prismatic Retroreflective Element Material

Obs.

Angle

Entrance

Angle

White

Yellow

Orange

Green

Red

Blue

Brown

0.2°

-0.4°

700

525

265

105

0.2°

+30°

325

245

120

0.5°

-0.4°

250

190

7.5

0.5°

+30°

115

3.5

Type IX Micro Prismatic Retroreflective Element Material

Obs.

Angle

Entrance

Angle

White

Yellow

Orange

Green

Red

Blue

0.2°

-0.4°

380

285

145

0.2°

+30°

215

162

0.5°

-0.4°

240

180

0.5°

+30°

135

100

6.0

1.0

-0.4°

8.0

3.6

1.0

+30°

4.5

9.0

2.0

Type X Micro Prismatic Retroreflective Element Material

Obs. Angle

Entrance Angle

Fluorescent Orange

0.2°

-0.4°

200

0.2°

+30°

0.5°

-0.4°

0.5°

+30°

Page 9-182

Signing Materials and Fabrication

The wet performance measurements on unweathered sheeting shall be conducted in
accordance with one of the following methods:
1. The 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 percent of the above values.

2. Samples shall be submerged in a tank of clean water (approximately 72°F) for a

period of 5 minutes. 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. The wet sheeting shall show
no apparent loss of reflective performance as compared to dry material.

The sheeting shall conform to the applicable daytime color and luminance factor
requirements of ASTM D4956 when tested instrumentally in accordance with Section 8.4
of that Specification; OR, the diffuse day color of the reflective sheeting shall be visually
evaluated by comparison with the applicable Highway Color Tolerance Chart. Color
comparison shall be made under north daylight or a scientific daylight having a color
temperature from 6500 degrees to 7500 degrees Kelvin. Daytime color evaluation shall
be illuminated at 45 degrees and viewed at 90 degrees. There shall be no significant color
shift when viewed under nighttime (retroreflective) conditions.

The reflective sheeting shall have a pre-coated pressure sensitive adhesive (Class 1) or
a heat-activated adhesive (Class 2) either of which will adhere to flat, clean surfaces
without necessity of additional adhesive coats on the reflective sheeting or application
surface. Chemical activators shall not be used to activate Class 2 adhesive. The pre-
coated adhesive shall be protected by an easily removed liner which, when removed, shall
not have a staining effect on the reflective sheeting and shall be mildew resistant. The
protective liner attached to the adhesive shall be removable by peeling without soaking
in water or other solvents and shall be easily removed after storage for 4 hours at 150ºF
under weight of 215 psi. The sheeting with liner removed, conditioned for 24 hours at
72°F and 50 percent relative humidity, shall be sufficiently flexible to show no cracking
when bent around a 1.2-inch diameter mandrel with the adhesive side contacting the
mandrel. For ease of testing, talcum powder may be spread on the adhesive to prevent
sticking to the mandrel. The sheeting surface shall be smooth and flat to facilitate self-
cleaning in the rain, regular cleaning, and wet performance, and exhibit 85 degrees
glossmeter rating of not less than 50 when tested in accordance with ASTM D523. The
sheeting surface shall be readily processed and compatible with transparent and opaque
process colors and show no loss of the color coat with normal handling, cutting, and
application. The sheeting shall permit cutting and color processing at temperatures of
60°F to 100°F and 20 to 80 percent RH. The sheeting shall be heat resistant and permit
force curing without staining of unapplied sheeting or applied sheeting at temperatures
recommended by the manufacturer not to exceed 150°F for unapplied sheeting or 200°F
for applied sheeting. The sheeting surface shall be solvent resistant to permit cleaning by
wiping with a clean soft cloth dampened with VM&P Naphtha or mineral spirits.

Signing Materials and Fabrication

9-28

The adhesive shall form a durable bond to smooth, corrosion and weather resistant
surfaces and permit the reflective sheeting to adhere securely, 48 hours after application
at temperatures of -30°F to 200°F. The adhesive bond shall be sufficient to render the
applied sheeting vandal-resistant and prevent its shocking off when subjected to an
impact energy of 20 ft. lbs. applied with a hemispherical tipped object 1 inch in diameter
at -0°F. The test specimen shall be applied to aluminum backing not less than 0.080 inch
thick and having a dimension of not less than 4 inches square. During testing, the
specimen shall be supported on a 3-inch diameter ring.

The adhesion test shall conform to ASTM D4956 with the addition of the temperatures
noted above.

The resistance to accelerated weathering shall be as described in ASTM D4956 except
the weathering apparatus and procedure shall be in accordance with ASTM G154.

The reflective sheeting shall be sufficiently flexible to be cut to shape easily and permit
application over, and conform to, moderate shallow embossing characteristic of certain
sign borders and symbols. The tensile strength of the sheeting shall be 5 to 20 pounds
per square inch width when conditioned for 48 hours in accordance to ASTM D685 and
tested in accordance with ASTM D828. Following liner removal, the reflective sheeting
shall not shrink more than ¹/

inch in 10 minutes nor more than ⅛ inch in 24 hours in any

dimension per 9 inch square at 72°F and 50 percent relative humidity.

The sheeting, when applied according to manufacturer’s recommendations to cleaned and
etched 0.020 by 2 by 8-inch aluminum, conditioned (24 hours) and tested at 72°F and
50 percent relative humidity, shall be sufficiently flexible to show no cracking when bent
around a ¾-inch diameter mandrel.

9-28.12(1) Application

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

9-28.12(2) Edge Treatment

All edges and splices of reflective sheeting signs shall be coated with an edge sealer when
recommended by the manufacturer of the reflectorized sheeting.

9-28.12(3) Splices and Color Matching

Splicing of reflective sheeting shall not be permitted on signs or panels with dimensions
up to and including 48 inches in height or width unless the reflective sheeting specified
does not come in this width, then the widest width material 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 3/16 inch. The 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 1/32 inch. Color matching of
adjacent sheets of reflective sheeting comprising a sign shall be accomplished without

Page 9-184

Signing Materials and Fabrication

a noticeable difference in color. No borders shall be spliced other than the splice of the
tangent border to the corner radius.

9-28.13

Demountable Prismatic Reflectorized Message and Borders

The letters, digits, and alphabet accessories shall consist of embossed 0.040-inch thick
sheet aluminum frames conforming to ASTM B209 grade 3003-H14 in which prismatic
reflectors are installed to prevent their displacement in handling or service. Letters in
which reflectors are assembled by means of tape are unacceptable. The plastic reflectors
face shall be colorless and be entirely smooth to present a water repellent and dirt
resistant surface. The area indicating the letter shape that is not reflectorized shall be
white for maximum daytime contrast with the sign background. All letters shall be free
of any imperfections and shall present a high quality appearance. Demountable prismatic
border shall be comprised of a minimum length of 2 feet with allowance of one shorter
section between each corner radius.

Letters shall be fastened to the sign with aluminum screws or blind rivets conforming to
ASTM B209 grade 2024-T4.

The coefficient of retroreflection of each reflex reflector intended for use in cutout
letters, symbols, and accessories shall be equal to or exceed the following minimum
values with measurements made with reflectors spinning.

Observation Angle

(Degrees)

Entrance Angle

(Degrees)

Coefficient of Retroreflection Candle

Power/Square inch/Foot Candle

0.1

14.0

0.1

5.6

Failure to meet the specific minimum values shall constitute failure of the reflector
being used. Upon failure of more than two of the 50 samples tested, a resample of
100 reflectors shall be tested. Failure of more than four of these samples shall be cause
for rejection of the lot.

9-28.14

Sign Support Structures

All sign support structures shall be constructed as shown in the Plans.

9-28.14(1) Timber Sign Posts

At the Contractor’s options, timber sign posts and mileposts shall be treated Douglas Fir
or treated Hem-Fir meeting the grades specified in

Section 9-09.2

. Douglas Fir and Hem-

Fir posts shall be given a treatment in accordance with

Section 9-09.3(1)

. Preservative

and retention shall be as shown in

Section 9-16.2

for sawn posts.

Signing Materials and Fabrication

9-28

9-28.14(2) Steel Structures and Posts

Truss chords, struts, and diagonals, end posts, and end post struts and diagonals for sign
bridge structures and cantilever sign structures shall conform to either ASTM A36 or
ASTM A53 Grade B Type E or S. The nominal pipe diameter and the pipe wall thickness
shall be as shown in the Plans or

Standard Plans

. All other structural steel for sign bridge

structures and cantilever sign structures shall conform to either ASTM A36 or ASTM
A992. Truss member connection hardware shall conform to

Section 9-06.5(3)

Pipe members for bridge mounted sign brackets shall conform to ASTM A53 Grade B
Type E or S, and shall be Schedule 40 unless otherwise specified. All other structural
steel for bridge mounted sign brackets shall conform to either ASTM A36 or ASTM
A992. U bolts, and associated nuts and washers, shall be stainless steel conforming to

Section 9-28.11

, and shall be fabricated hot.

Anchor rods for sign bridge and cantilever sign structure foundations shall conform to

Section 9-06.5(4)

, including Supplemental Requirement S4 tested at -20°F. Nuts and

washers for sign bridge and cantilever sign structure foundations shall conform to ASTM
A563 Grade DH and ASTM F436, respectively.

Steel sign structures and posts shall be galvanized after fabrication in accordance with
AASHTO M111, unless noted otherwise in the Plans. All bolts, nuts, and washers shall be
galvanized after fabrication in accordance with ASTM F 2329. Unless otherwise specified
in the Plans or Special Provisions, metal surfaces shall not be painted.

Except as otherwise noted, steel used for sign structures and posts shall have a controlled
silicon content of either 0.00 to 0.06 percent or 0.15 to 0.25 percent. Steel used for slip
bases (SB-1, SB-2, SB-3) and heavy-duty anchors shall have a controlled silicon maximum
of 0.40 percent. If the Plans or Special Provisions specify painting of the galvanized steel
surfaces, then the controlled silicon content requirement does not apply for those steel
members. Mill test certificates verifying the silicon content of the steel shall be submitted
to both the galvanizer and the Engineer prior to beginning galvanizing operations.

Minor fabricating and modifications necessary for galvanizing will be allowed if not
detrimental to the end product as determined by the Engineer. If such modifications are
contemplated, the Contractor shall submit a Type 2 Working Drawing of the proposed
modifications.

9-28.14(3) Aluminum Structures

Welding of aluminum shall be in accordance with AWS D1.2/D1.2M, latest edition,
Structural Welding Code – Aluminum.

Aluminum alloy filler metals utilized on anodized structures shall result in color matching
to base metals.

9-28.15 Vacant

Page 9-186

Illumination, Signal, Electrical

9-29

Illumination, Signal, Electrical

9-29.1

Conduit, Innerduct, and Outerduct

Conduit shall be free from defects, including out of round and foreign inclusions. Conduit
shall be uniform in color, density, and physical properties. The inside shall be smooth
and free from burrs, which could damage cable during installation. Conduit ends shall
be cut square to the inside diameter and supplied with thread protectors. All conduit,
conduit fittings, and associated hardware/appurtenances shall be listed by a Nationally
Recognized Testing Laboratory.

9-29.1(1) Rigid Metal Conduit, Galvanized Steel Outerduct, and Fittings

Rigid metal conduit shall be straight and be rigid galvanized steel or stainless steel, as
required, and bear the mark of a Nationally Recognized Testing Laboratory. Exterior and
interior surfaces of the galvanized steel conduit, except threaded ends, shall be uniformly
and adequately zinc coated by a hot-dip galvanizing process. The average of the zinc
coating shall comply with Federal Specification WW-C-581d.

9-29.1(2) Rigid Metal Conduit Fittings and Appurtenances

Couplings for rigid metal-type conduits may be either hot-dip or electroplated galvanized.

Conduit bodies and fittings for rigid steel conduit systems shall be listed by a Nationally
Recognized Testing Laboratory listed for wet locations and shall be hot-dip galvanized
malleable iron or bronze. Conduit bodies shall have tapered threads and include a bolt on
cover with stainless steel screws and a neoprene gasket seal.

Grounding end bushings shall be bronze or galvanized malleable iron with copper, tinned
copper, stainless steel, or integral lug with stainless steel clamping screw, mounting screw,
and set screw.

Conduit clamps and straps shall be Type 304 or Type 316 stainless steel or hot-dip
galvanized. Two-hole-type straps shall span the entire width of the support channel and
attach to the supports on both sides of the conduit with bolts and associated hardware.
Two-piece conduit clamps shall interlock with the support channel with a single bolt.

Conduit supports for surface-mounted conduit shall be hot-dip galvanized or Type 304
or Type 316 stainless steel channel using Type 304 or Type 316 stainless steel bolts and
spring nuts.

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 87