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

Page 8-142

Pavement Marking

Apply materials to new HMA that is sufficiently cured according to the manufacturer’s
recommendations. Typically, Type D material applied to new HMA pavement requires a
pavement cure period of 21 days. This cure period may be reduced if the manufacturer
performs a successful bond test and approves the reduction of the pavement cure period.

For new Portland cement concrete surfaces, remove curing compounds and laitance by
an approved mechanical means. Air blast the pavement with a high-pressure system to
remove extraneous or loose material. Apply materials to concrete that has reached a
minimum compressive strength of 2,500 psi and that is sufficiently cured according to the
manufacturer’s recommendations. Typically, Type D material applied to Portland cement
concrete pavement requires a pavement cure period of 28 days. This cure period may be
reduced if the manufacturer performs a successful bond test and approves the reduction
of the pavement cure period.

After the pavement surface is clean and dry, apply primer as recommended by the
manufacturer to the area receiving the pavement markings. Apply the primer in a
continuous, solid film according to the recommendations of the primer manufacturer and
the pavement markings manufacturer.

8-22.3(3) Marking Application

8-22.3(3)A

Marking Colors

Lane line and right edge line shall be white in color. Centerline and left edge line shall
be yellow in color. Transverse markings shall be white, except as otherwise noted in the

Standard Plans

8-22.3(3)B

Line Patterns

Solid Line – A continuous line without gaps.

Broken Line – A line consisting of solid line segments separated by gaps.

Dotted Line – A broken line with noticeably shorter line segments separated by noticeably
shorter gaps.

8-22.3(3)C

Line Surfaces

Flat Lines – Pavement marking lines with a flat surface.

Profiled Marking – A profiled pavement marking is a marking that consists of a base line
thickness and a profiled thickness, which is a portion of the pavement marking line that is
applied at a greater thickness than the base line thickness. Profiles shall be applied using
the extruded method in the same application as the base line. The profiles may be slightly
rounded provided the minimum profile thickness is the same throughout the length of the
profile. See the Plans for the construction details.

Embossed Plastic Line – Embossed plastic lines consist of a flat line with transverse
grooves. An embossed plastic line may also have profiles. See the Plans for the
construction details.

Pavement Marking

8-22

8-22.3(3)D

Line Applications

Surface Line – A line constructed by applying pavement marking material directly to the
pavement surface or existing pavement marking.

Grooved Line – A line constructed by grinding or saw cutting a groove into the pavement
surface and spraying, extruding, or gluing pavement marking material into the groove.
Groove depth is measured vertically from the bottom of a 2 foot or longer straightedge
placed on the roadway surface to the ground surface. The groove depth is dependent
upon the material used, the pavement surface, and the location. See these Standard
Specifications, the project Plans, and Special Provisions. Grooved line pavement marking
shall not be constructed on bridge decks or on bridge approach slabs.

8-22.3(3)E Installation

Apply pavement marking materials to clean, dry pavement surfaces and according to the
following:
1.  Place material according to the manufacture’s recommendations,
2.  Place parallel double lines in one pass,
3.  The top of pavement marking shall be smooth and uniform,
4.  Line ends shall be square and clean,
5.  Place pavement marking lines parallel and true to line, and
6.  Place markings in proper alignment with existing markings.

When applying paint, Type A or Type C material, ensure that both the pavement surface
and the air temperature at the time of application are not less than 50°F and rising. When
applying Type B or Type D material, ensure that both the pavement surface and the air
temperature at the time of application are not less than 40°F and rising.

Ensure that the Type A thermoplastic material meets the manufacturer’s temperature
specifications when it contacts the pavement surface.

Two applications of paint will be required to complete all paint markings. The second
application of paint shall be squarely on top of the first pass. The time period between
paint applications will vary depending on the type of pavement and paint (low VOC
waterborne or low VOC solvent) as follows:

Pavement Type

Paint Type

Time Period

Bituminous Surface Treatment

Low VOC Waterborne

4 hours min., 48 hours max.

Hot Mix Asphalt Pavement

Low VOC Waterborne

4 hours min., 30 days max.

Cement Concrete Pavement

Low VOC Waterborne

4 hours min., 30 days max.

Bituminous Surface Treatment

Low VOC Solvent

40 min. min., 48 hrs. max.

Hot Mix Asphalt Pavement

Low VOC Solvent

40 min. min., 30 days max.

Cement Concrete Pavement

Low VOC Solvent

40 min. min., 30 days max.

Page 8-144

Pavement Marking

Centerlines on two-lane Highways with broken line patterns, paint, or plastic shall be
applied in the increasing milepost direction so they are in cycle with existing broken line
patterns at the beginning of the project. Broken line patterns applied to multilane or
divided Roadways shall be applied in cycle in the direction of travel.

Where paint is applied on centerline on two-way roads with bituminous surface treatment
or centerline rumble strips, the second paint application shall be applied in the opposite
(decreasing milepost) direction as the first application (increasing milepost) direction. This
will require minor broken line pattern corrections for curves on the second application.

8-22.3(3)F

Application Thickness

Pavement markings shall be applied at the following base line thickness measured above
the pavement surface or above the groove bottom for grooved markings in thousandths
of an inch (mils):

Marking Material Application

HMA

PCC

BST

Groove

Depth

Paint – first coat

spray

Paint – second coat

spray

Type A – flat/transverse & symbols

extruded

125

Type A – flat/long line & symbols

spray

120

Type A – with profiles

extruded

120

Type A – embossed

extruded

160

Type A – embossed with profiles

extruded

160

Type A – grooved/flat/long line

extruded

230

250

Type B – flat/transverse & symbols

heat fused

125

Type C-2 – flat/transverse & symbols

adhesive

Type C-1 & 2 – flat/long line

adhesive

Type C-1 – grooved/flat/long line

adhesive

100

Type D – flat/transverse & symbols

spray

120

Type D – flat/transverse & symbols

extruded

120

Type D – flat/long line

spray

120

Type D – flat/long line

extruded

120

Type D – profiled/long line

extruded

120

Type D – grooved/flat/long line

extruded

230

250

Pavement Marking

8-22

Liquid pavement marking material yield per gallon depending on thickness shall not
exceed the following:

Mils thickness

Feet of 4″ line/gallon

Square feet/gallon

483

161

322

108

268

242

220

202

161

122

107

90 with profiles

120

120 with profiles

230

Solid pavement marking material (Type A) yield per 50-pound bag shall not exceed the
following:

Mils thickness

Feet of 4″ line/50# bag

Square feet/50# bag

30 – flat

358

120

45 – flat

240

60 – flat

179

90 – flat

120

90 – flat with profiles

120 – flat

120 – flat with profiles

125 – embossed

125 – embossed with profiles

230 – flat grooved

All grooved lines shall be applied into a groove cut or ground into the pavement. For
Type A or Type D material, the groove shall be cut or ground with equipment to produce
a smooth square groove 4 inches wide. For Type C-1 material, the groove shall be cut
with equipment to produce a smooth bottom square groove with a width in accordance
with the material manufacturer’s recommendation. After grinding, clean the groove.
Immediately before placing the marking material, clean the groove with high-pressure air.

Page 8-146

Pavement Marking

8-22.3(3)G

Glass beads

Top dress glass beads shall be applied to all spray and extruded pavement marking
material. Glass beads shall be applied by a bead dispenser immediately following the
pavement marking material application. Glass bead dispensers shall apply the glass beads
in a manner such that the beads appear uniform on the entire pavement marking surface
with 50 to 60 percent embedment. Hand casting of beads will not be allowed.

Glass beads shall be applied to 10 or 15 mil thick paint at a minimum application rate
of 7 pounds per gallon of paint. For plastic pavement markings, glass bead type and
application rate shall be as recommended by the marking material manufacturer.

When two or more spray applications are required to meet thickness requirements for
Type A and Type D materials, top dressing with glass beads is only allowed on the last
application. The cure period between successive applications shall be in accordance
with the manufacturer’s recommendations. Any loose beads, dirt or other debris shall be
swept or blown off the line prior to application of each successive application. Successive
applications shall be applied squarely on top of the preceding application.

8-22.3(4) Tolerances for Lines

Allowable tolerances for lines are as follows:

Length of Line – The longitudinal accumulative error within a 40 foot length of
broken line shall not exceed plus or minus 1 inch. The broken line segment shall not
be less than 10 feet.
Width of Line – The width of the line shall not be less than the specified line width
or greater than the specified line width plus ¼ inch.
Lane Width – The lane width, which is defined as the lateral width from the edge
of pavement to the center of the lane line or between the centers of successive
lane lines, shall not vary from the widths shown in the Contract by more than plus
or minus 4 inches.
Thickness – A thickness tolerance not exceeding plus 10 percent will be allowed
for thickness or yield in paint and plastic material application.
Parallel Lines – The gap tolerance between parallel lines is plus or minus ½ inch.

8-22.3(5) Installation Instructions

Installation instructions for plastic markings shall be provided for the Engineer.
The instructions shall include equipment requirements, approved work methods
and procedures, material application temperature range, air and pavement surface
temperature requirements, weather limitations, precautions, and all other requirements
for successful application and material performance. Do not use materials with
incomplete or missing instructions. All materials including glass beads shall be installed
according to the manufacturer’s recommendations. A manufacturer’s technical
representative shall be present at the initial installation of plastic material to approve the
installation procedure or the material manufacturer shall certify that the Contractor will
install the plastic material in accordance with their recommended procedure.

Pavement Marking

8-22

8-22.3(6) Removal of Pavement Markings

Pavement markings to be removed shall be obliterated until all blemishes caused by the
pavement marking removal conform to the coloration of the adjacent pavement.

Grinding to remove pavement markings in their entirety is allowed in areas designated
for applications of either Hot Mix Asphalt (HMA) or Bituminous Surface Treatment (BST).
Pavement marking removal shall be performed from April 1st through September 30

and only in those areas that shall be paved within the same time window as the grinding,
unless otherwise allowed by the Engineer in writing.

For all cement concrete pavement and areas that will not be overlaid with hot mix asphalt
or BST, grinding is allowed to a depth just above the pavement surface and then Water
blasting or shot blasting shall be required to remove the remaining pavement markings.

If in the opinion of the Engineer, the pavement is materially damaged by pavement
marking removal, such damage shall be repaired by the Contractor in accordance with

Section 1-07.13(1)

. Sand or other material deposited on the pavement as a result of

removing lines and markings shall be removed as the Work progresses to avoid hazardous
conditions. Accumulation of sand or other material which might interfere with drainage
will not be permitted.

8-22.4 Measurement

Center line, center line with no pass line, double center line, double lane line, edge line,
solid lane line, dotted extension line, lane line, reversible lane line, and two-way left-
turn center line will be measured by the completed linear foot as “Paint Line”, “Plastic
Line”, “Embossed Plastic Line”, “Profiled Plastic Line”, “Profiled Embossed Plastic Line” or
Grooved Plastic Line”.

The measurement for “Paint Line” will be based on a marking system capable of
simultaneous application of three 4-inch lines with two 4-inch spaces. No deduction will
be made for the unmarked area when the marking includes a broken line such as center
line, dotted extension line, center line with no-pass line, lane line, reversible lane line, or
two-way left-turn center line. No additional measurement will be made when more than
one line can be installed on a single pass such as center line with no-pass line, double
center line, double lane line, reversible lane line, or two-way left-turn center line.

The measurement for “Plastic Line”, “Embossed Plastic Line”, “Profiled Plastic Line”,
“Profiled Embossed Plastic Line”, or “Grooved Plastic Line” will be based on the total
length of each 4 inch wide plastic line installed. No deduction will be made for the
unmarked area when the marking includes a broken line such as, center line, dotted
extension line, center line with no-pass line, lane line, reversible lane line, or two-way left-
turn center line.

The measurement for “Painted Wide Lane Line”, “Plastic Wide Lane Line”, “Profiled Plastic
Wide Lane Line”, “Painted Barrier Center Line”, “Plastic Barrier Center Line”, “Painted
Stop Line”, “Plastic Stop Line”, “Painted Wide Dotted Entry Line”, or “Plastic Wide Dotted
Entry Line” will be based on the total length of each painted, plastic or profiled plastic line

Page 8-148

Pavement Marking

installed. No deduction will be made for the unmarked area when the marking includes
a broken line such as, wide broken lane line, drop lane line, wide dotted lane line or wide
dotted entry line. The measurement for double wide lane line will be based on the total
length of each wide lane line installed.

No additional measurement for payment will be made for the required second application
of paint. No additional measurement for payment will be made for additional applications
required to meet thickness requirements for plastic markings.

Diagonal lines used to delineate parking stalls that are constructed of painted or plastic
4-inch lines will be measured as “Paint Line” or “Plastic Line” by the linear foot of line
installed. Crosswalk line will be measured by the square foot of marking installed.

Crosshatch markings used to delineate median and gore areas will be measured by the
completed linear foot as “Painted Crosshatch Marking” or “Plastic Crosshatch Marking”.

The measurement for “Painted Crosshatch Marking” and for “Plastic Crosshatch Marking”
will be based on the total length of each 8-inch or 12-inch wide line installed.

Traffic arrows, traffic letters, access parking space symbols, HOV symbols, railroad
crossing symbols, drainage markings, junction box markings, bicycle lane symbols, aerial
surveillance full, and ½ markers, yield line symbols, yield ahead symbols, and speed bump
symbols will be measured per each. Type 1 through 6 traffic arrows will be measured as
one unit each, regardless of the number of arrow heads.

Removal of lines, 4, 8, 18, and 20 inches in width will be measured by the linear foot, with
no deduction being made for the unmarked area when the marking includes a gap.

Removal of traffic arrows, traffic letters, access parking space symbol, HOV lane symbol,
railroad crossing symbol, bicycle lane symbols, drainage markings, aerial surveillance full
and ½ markers, yield line symbol, yield ahead symbol, and speed bump symbol will be
measured per each. Removal of crosswalk lines will be measured by the square foot of
lines removed.

8-22.5 Payment

Payment will be made for each of the following Bid items that are included in the
Proposal:

“Paint Line”, per linear foot.
“Plastic Line”, per linear foot.
“Embossed Plastic Line”, per linear foot.
“Profiled Plastic Line”, per linear foot.
“Profiled Embossed Plastic Line”, per linear foot.
“Grooved Plastic Line”, per linear foot.
“Painted Wide Lane Line”, per linear foot.
“Plastic Wide Lane Line”, per linear foot.

Pavement Marking

8-22

“Profiled Plastic Wide Lane Line”, per linear foot.
“Painted Barrier Center Line”, per linear foot.
“Plastic Barrier Center Line”, per linear foot.
“Painted Stop Line”, per linear foot.
“Plastic Stop Line”, per linear foot.
“Painted Crosswalk Line”, per square foot.
“Plastic Crosswalk Line”, per square foot.
“Painted Crosshatch Marking”, per linear foot.
“Plastic Crosshatch Marking”, per linear foot.
“Painted Wide Dotted Entry Line”, per linear foot.
“Plastic Wide Dotted Entry Line”, per linear foot.
“Painted Traffic Arrow”, per each.
“Plastic Traffic Arrow”, per each.
“Painted Traffic Letter”, per each.
“Plastic Traffic Letter”, per each.
“Painted Access Parking Space Symbol”, per each.
“Plastic Access Parking Space Symbol”, per each.
“Painted Railroad Crossing Symbol”, per each.
“Plastic Railroad Crossing Symbol”, per each.
“Painted Bicycle Lane Symbol”, per each.
“Plastic Bicycle Lane Symbol”, per each.
“Painted Drainage Marking”, per each.
“Plastic Drainage Marking”, per each.
“Painted Junction Box Marking”, per each.
“Plastic Junction Box Marking”, per each.
“Painted Aerial Surveillance Full Marker”, per each.
“Plastic Aerial Surveillance Full Marker”, per each.
“Painted Aerial Surveillance ½ Marker”, per each.
“Plastic Aerial Surveillance ½ Marker”, per each.
“Painted Access Parking Space Symbol with Background”, per each.
“Plastic Access Parking Space Symbol with Background”, per each.
“Painted HOV Lane Symbol”, per each.
“Plastic HOV Lane Symbol”, per each.

Temporary Pavement Markings

8-23

Temporary Pavement Markings

8-23.1 Description

The Work consists of furnishing and installing temporary pavement markings. Temporary
pavement markings shall be provided where noted in the Plans and for all lane shifts and
detours resulting from construction activities; or when permanent markings are removed
because of construction operations.

8-23.2 Materials

Materials for temporary markings shall be paint, plastic, tape, raised pavement markers
or flexible raised pavement markers. Materials for pavement markings shall meet the
following requirements:

Raised Pavement Marker

9-21

Temporary Marking Paint

9-34.2(6)

Plastic

9-34.3

Glass Beads for Pavement Marking Materials

9-34.4

Temporary Pavement Marking Tape

9-34.5

Temporary Flexible Raised Pavement Markers

9-34.6

8-23.3

Construction Requirements

8-23.3(1) General

The Contractor shall select the type of pavement marking material in accordance with the
Contract.

8-23.3(2) Preliminary Spotting

All preliminary layout and marking in preparation for application and the application and
removal of temporary pavement markings shall be the responsibility of the Contractor.

8-23.3(3) Preparation of Roadway Surface

Surface preparation for temporary pavement markings shall be in accordance with the
manufacturer’s recommendations.

8-23.3(4) Pavement Marking Application

8-23.3(4)A

Temporary Pavement Markings – Short Duration

Temporary pavement markings – short duration shall meet the following requirements:

Temporary Center Line – A BROKEN line used to delineate adjacent lanes of traffic
moving in opposite directions. The broken pattern shall be based on a 40-foot unit,
consisting of a 4-foot line with a 36-foot gap if paint or tape is used. If temporary raised
pavement markers are used, the pattern shall be based on a 40-foot unit, consisting of a
grouping of three temporary raised pavement markers, each spaced 3 feet apart, with a
34 foot gap.

Page 8-152

Temporary Pavement Markings

Temporary Edge Line – A SOLID line used on the edges of Traveled Way. The line shall be
continuous if paint or tape is used. If temporary raised pavement markers are used, the
line shall consist of markers installed continuously at 5-foot spacings.

Temporary Lane Line – A BROKEN line used to delineate adjacent lanes with traffic
traveling in the same direction. The broken pattern shall be based on a 40-foot unit,
consisting of a 4-foot line with a 36-foot gap, if paint or tape is used. If temporary raised
pavement markers are used, the pattern shall be based on a 40-foot unit, consisting of a
grouping of three temporary raised pavement markers, each spaced 3 feet apart, with a
34 foot gap.

Lane line and right edge line shall be white in color. Center line and left edge line shall be
yellow in color. Edge Lines shall be installed only if specifically required in the Contract. All
temporary pavement markings shall be retroreflective.

8-23.3(4)A1 Temporary Pavement Marking Paint

Paint used for short duration temporary pavement markings shall be applied in one
application at a thickness of 15 mils or 108 square feet per gallon. Glass beads shall be in
accordance with

Section 8-22.3(3)G

8-23.3(4)A2 Temporary Pavement Marking Tape

Application of temporary pavement marking tape shall be in conformance with the
manufacturer’s recommendations.

Black mask pavement marking tape shall mask the existing line in its entirety.

8-23.3(4)A3 Temporary Raised Pavement Markers

Temporary raised pavement markers are not allowed on bituminous surface treatments.

8-23.3(4)A4 Temporary

Flexible Raised Pavement Markers

Flexible raised pavement markers are required for new applications of bituminous
surface treatments. Flexible raised pavement markers are not allowed on other pavement
types unless otherwise specified or approved by the Engineer. Flexible raised pavement
markers shall be installed with the protective cover in place. The cover shall be removed
immediately after spraying asphaltic material.

8-23.3(4)B

Temporary Pavement Markings – Long Duration

Application of paint, pavement marking tape and plastic for long duration pavement
markings shall meet the requirements of

Section 8-22.3(3)

; application of raised pavement

markers shall meet the requirements of

Section 8-09.3

; and application of flexible

pavement markings shall be in conformance with the manufacturer’s recommendations.

Temporary Pavement Markings

8-23

8-23.3(4)C

Tolerance for Lines

Tolerance for lines shall conform to

Section 8-22.3(4)

8-23.3(4)D

Maintenance of Pavement Markings

Temporary pavement markings shall be maintained in serviceable condition throughout
the project until permanent pavement markings are installed. As directed by the Engineer;
temporary pavement markings that are damaged, including normal wear by traffic, shall be
repaired or replaced immediately. Repaired and replaced pavement markings shall meet
the requirements for the original pavement marking.

8-23.3(4)E

Removal of Pavement Markings

Removal of temporary paint is not required prior to paving; all other temporary pavement
markings shall be removed.

All temporary pavement markings that are required on the wearing course prior to
construction of permanent pavement markings and are not a part of the permanent
markings shall be completely removed concurrent with or immediately subsequent to the
construction of the permanent pavement markings in accordance with the manufacturer’s
permanent marking application instructions. Temporary flexible raised pavement markers
on bituminous surface treatment pavements shall be cut off flush with the surface if their
location conflicts with the alignment of the permanent pavement markings. All other
temporary pavement markings shall be removed in accordance with

Section 8-22.3(6)

All damage to the permanent Work caused by removing temporary pavement markings
shall be repaired by the Contractor at no additional cost to the Contracting Agency.

8-23.4 Measurement

Temporary pavement markings will be measured by the linear foot of each installed line or
grouping of markers, with no deduction for gaps in the line or markers and no additional
measurement for the second application of paint required for long duration paint lines.
Short duration and long duration temporary pavement markings will be measured for the
initial installation only.

8-23.5 Payment

Payment will be made for each of the following Bid items that are included in the
Proposal:

“Temporary Pavement Marking – Short Duration”, per linear foot.
“Temporary Pavement Marking – Long Duration”, per linear foot.
The unit Contract price per linear foot for “Temporary Pavement Marking – Short
Duration” and “Temporary Pavement Marking – Long Duration” shall be full pay for
all Work.

Page 8-154

Rock and Gravity Block Wall and Gabion Cribbing

8-24

Rock and Gravity Block Wall and Gabion Cribbing

8-24.1 Description

This Work consists of constructing rock and gravity block wall(s), and gabion cribbing in
accordance with the Plans, Special Provisions, these Specifications, or as designated by
the Engineer.

8-24.2 Materials

Materials shall meet the requirements of the following Sections:

Rock for Rock Wall and Chinking Material

9-13.7(1)

Backfill for Rock Wall

9-13.7(2)

Gabion Cribbing

9-27.3

Wire Mesh Fabric

9-27.3(1)

PVC Coating for Welded Wire Mesh Fabric

9-27.3(2)

Gabion Basket Fasteners

9-27.3(4)

Stone

9-27.3(6)

Construction Geotextile

9-33

Materials for gravity block walls shall be as specified in the Special Provisions.

8-24.3

Construction Requirements

8-24.3(1) Rock Wall

8-24.3(1)A

Geometric Tolerances

The completed wall shall meet the following tolerances:
1. Wall batter shall be 6:1 or flatter as specified in the Plans.
2. The exterior slope plane and grade in the finished surface of the wall shall be plus or

minus 6 inches.

3. The maximum void between adjacent rocks shall be 6 inches as measured at the

smallest dimensions of the void within the thickness of the wall.

8-24.3(1)B Excavation

Excavation shall conform to

Section 2-09.3(4)

, and to the limits and construction stages

shown in the Plans.

The Contractor shall restrict the excavation limits to the length of rock wall that can
be constructed in 1 day’s Work, except as otherwise noted. The Engineer may permit
excavation beyond the limits that can be completed in 1 day’s Work provided the
Contractor either demonstrates that the excavation will remain stable until the rock wall is
completed, or shores the excavation in accordance with

Section 2-09.3(4)

Slope above the rock wall shall be established prior to excavating for the wall.

Rock and Gravity Block Wall and Gabion Cribbing

8-24

8-24.3(1)C

Foundation Preparation

The foundation for the wall shall be graded as shown in the Plans.

Prior to rock placement, the foundation, if not in rock, shall be compacted as approved by
the Engineer. Any foundation soils found to be unsuitable shall be removed and replaced
in accordance with

Section 2-09.3(1)C

Base course rocks shall have full contact with the foundation soils. If necessary, the
excavation shall be shaped to fit the rocks. Rocks may be dropped to shape the ground
provided the rocks do not crack. Cracked rocks shall be replaced and the foundation
regraded to fit the replacement rock.

8-24.3(1)D

Construction Geotextile

Construction geotextile shall be of the type, and shall be placed, as shown in the Plans.

8-24.3(1)E

Rock Placement and Backfill

Rocks shall be placed so there are no continuous joint planes in either the vertical or
lateral direction.

Where possible, rocks shall be placed so that the rock shall bear on at least two rocks
below it. Rocks shall be oriented so that flat surface contact points between adjacent
rocks are maximized. Point-to-point contact between adjacent rocks shall be minimized.
Each rock in a course shall be arranged so that the natural irregularities in the rocks key
the rocks together and so that the courses are keyed together.

Rocks shall increase in size from the top of the wall to the bottom at a uniform rate.
The minimum rock sizes, as referenced from the top of the wall, shall be as follows:

Depth From

Top of Wall (feet)

Minimum Rock Size at

Depth From Top of Wall

Three Man

Four Man

Five Man

Rocks at the top of the wall shall be Two Man or larger.

Where voids larger than 6 inches are present, chinking rock shall be keyed between
the rocks to fill the void.

Backfill for the rock wall shall be placed behind each course and tamped to provide
a stable condition prior to placing rocks for the next successive course.

For rock walls constructed in fills, the fill shall be overbuilt and cut back to construct
the wall.

Page 8-156

Rock and Gravity Block Wall and Gabion Cribbing

8-24.3(2) Gravity Block Wall

Excavation shall conform to

Section 2-09.3(4)

, and to the limits and construction stages

shown in the Plans. Foundation soils found to be unsuitable shall be removed and
replaced in accordance with

Section 2-09.3(1)C

. Slope above the gravity block wall shall

be established prior to beginning any excavation for the wall.

Gravity block walls are defined as a wall of modular blocks acting as a gravity wall to
retain soil. The modular blocks may have features designed to interlock the blocks
together. However there shall be no reinforcement of the retained soil nor any
reinforcement connection between the modular blocks and the retained soil.

Gravity block walls shall be constructed as specified in the Special Provisions and as
shown in the Plans.

8-24.3(3) Gabion Cribbing

8-24.3(3)A Foundations

Before placing any gabion cribbing, the Contractor shall excavate the foundation or bed
to the specified grade in accordance with

Section 2-09.3(4)

. Foundation soils found to be

unsuitable shall be removed and replaced in accordance with

Section 2-09.3(1)C

8-24.3(3)B Baskets

Baskets may be fabricated from either woven or welded steel wire; however, a gabion
Structure shall not include both. Baskets may be assembled with either lacing wire or clip
fasteners; however, a perimeter or diaphragm edge shall not include both.

8-24.3(3)C Dimensions

The Contractor shall supply gabion baskets in the lengths and heights the Plans require.
Each length shall be a multiple (double, triple, or greater) of horizontal width. Horizontal
width shall be 36 inches. All baskets from the same manufacturer shall be the same width
and shall be within a tolerance of 5 percent of the manufacturer’s stated sizes.

8-24.3(3)D

Fabrication of Baskets

Gabions shall be made so that the sides, ends, lid, and diaphragms can be assembled
into rectangular baskets of the required sizes at the construction site. Common-wall
construction may be used in gabion Structures up to 12 feet high. Common-wall
construction includes any basket where its top serves as the bottom of the one above it,
or where one wall also serves an adjacent basket. When gabion Structures are more than
12 feet high, the baskets shall have independent sides, ends, top, and bottom.

Each gabion shall be divided by diaphragms into cells the same length as horizontal basket
width. Diaphragms shall be made of the same mesh and gage as the basket body.

All perimeter and diaphragm edges shall be laced or clipped together so that joints are at
least as strong as the body of the mesh itself. The ends of the lacing shall be anchored by
three tight turns around the selvage wire.

Page 9-90

Paints and Related Materials

9-08.1(2)G

Intermediate and Stripe Coat, Single Component, Moisture-

Cured Polyurethane

Vehicle Type: Moisture-cured polyurethane.

Pigment: A minimum of 3.0 lbs. of micaceous iron oxide per gallon.

Intermediate and any stripe coat shall meet the following requirements:

Minimum volume solids 50 percent.
A minimum of 3.0 lbs/gal. of micaceous iron oxide.

The intermediate coating shall be certified by the manufacturer to be able to be
recoated by the top coat in a minimum of 4 days.

9-08.1(2)H

Top Coat, Single-Component, Moisture-Cured Polyurethane

Vehicle Type: Moisture-cured aliphatic polyurethane.

Color and Gloss: Meet the SAE AMS Standard 595 Color as specified in the table below.

The Top Coat shall meet the following requirements

The resin shall be an aliphatic urethane.
Minimum-volume solids 50 percent.
The top coat shall be a gloss or semi-gloss.

Color

Semi-Gloss

Washington Gray

26357

Mt. Baker Gray

26134

Mt. St. Helens Gray

26306

Cascade Green

24158

9-08.1(2)I

Rust-Penetrating Sealer

Rust-penetrating sealer shall be a two-component, chemically-cured, 100 percent solids
epoxy.

9-08.1(2)J

Black Enamel

The enamel shall conform to Federal Specification MIL PRF 24635E Type II Class 2.

9-08.1(2)K

Orange Equipment Enamel

The enamel shall be an alkyd gloss enamel conforming to Federal Specification MIL-PRF-
24635E Type II Class 1. The color, when dry, shall match that of SAE AMS Standard 595,
color number 12246.

For factory application to individual items of new equipment, samples and testing of the
enamel shall not be required; however, the equipment manufacturer shall match the color
specified and shall certify the quality of enamel used.

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 81