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

Fence and Guardrail

9-16

9-16.3(3) Galvanizing

W-beam or thrie beam rail elements and terminal sections shall be galvanized in
accordance with AASHTO M 180, Class A, Type II. Channel rails, splice plates, WF steel
posts, and base plates shall be galvanized in accordance with ASTM A123. Anchor
cables shall be galvanized in accordance with Federal Specification RR-W-410, Table II,
galvanized at finished size. Bolts, nuts, washers, plates, rods, and other hardware shall be
galvanized in accordance with ASTM A153.

9-16.3(4) Hardware

Unfinished bolts (ordinary machine bolts), nuts, and washers for unfinished bolts, shall
conform to

Section 9-06.5(1)

. High-strength bolts, nuts, and washers for high-strength

bolts shall conform to

Section 9-06.5(3)

Unfinished bolts shall be accepted by field verification and documentation that bolt heads
are stamped 307A. The Contractor shall submit a manufacturer’s certificate of compliance
per

Section 1-06.3

for high-strength bolts, nuts, and washers prior to installing any of the

hardware.

9-16.3(5) Anchors

Welding shall conform to

Section 6-03.3(25)

All welding shall be equal in strength to the parent metal.

All fabrication shall be complete and ready for assembly before galvanizing. No punching,
drilling, cutting, or welding will be permitted after galvanizing unless authorized by the
Engineer.

Foundation tubes shall be fabricated from steel conforming to the requirements of ASTM
A500, Grade B or ASTM A501.

The anchor plate assembly shall develop a minimum tensile strength of 40,000 pounds.

The anchor plate, W8 × 18, and metal plates shall be fabricated of steel conforming to the
Specifications of ASTM A36, except that the W8 × 18 may conform to ASTM A992.

Anchor cable shall be ¾ inch preformed, 6 by 19 wire strand core or independent wire
rope core (IWRC), galvanized, right regular lay manufactured of improved plow steel with
a minimum breaking strength of 42,800 pounds. Two certified copies of mill test reports
of the cable used shall be furnished to the Engineer.

Swaged cable fittings shall develop 100 percent of the specified breaking strength of the
cable. One swaged fitting attached to 3 feet of cable shall be furnished to the Engineer
for testing.

Page 9-140

Fence and Guardrail

The swaged fitting and stud assembly shall be of steel conforming to the requirements of
American Iron and Steel Institute C-1035 and shall be annealed and galvanized suitable
for cold swaging.

All metal components of the anchor and cable assembly and not less than the top
14 inches of the W8 × 18 for the Type 2 anchor shall be galvanized in accordance with

Section 9-16.3(3)

Cement concrete shall conform to the requirements of

Section 6-02.3(2)B

Cement grout shall conform to

Section 9-20.3(4)

and consist of one part portland cement

or blended hydraulic cement and two parts sand.

9-16.3(6) Inspection and Acceptance

The Contractor shall give notice to the Engineer before the rail elements are fabricated
in order that inspections may be provided. The Contractor shall arrange for all facilities
necessary for the inspection of material and workmanship at the point of fabrication
of the rail element, and inspectors shall be allowed free access to necessary parts of
the premises.

The Inspector shall have the authority to reject materials or workmanship which do not
fulfill the requirements of these Specifications. In cases of dispute, the Contractor may
appeal to the Engineer, whose decision will be final.

The Inspector may accept a mill test report certifying that the steel used in fabricating
the rail element meets the requirements of the Specifications. The Contracting
Agency reserves the right, however, to require the Contractor to furnish samples of
the steel proposed for use and to determine to its satisfaction that the steel meets
the Specification requirements. Steel rail elements, fittings, end section hardware, and
bolts may be accepted by the Engineer based on the Manufacturer’s Certification of
Compliance.

9-16.4

Wire Mesh Slope Protection

9-16.4(1) General

All metal material used in the construction of wire mesh slope protection shall be new and
galvanized. Imperfectly galvanized material or material upon which serious abrasion of
galvanizing occurs will not be acceptable.

9-16.4(2) Wire Mesh

The galvanized wire mesh shall be a Style 1 double-twisted hexagonal mesh conforming
to ASTM A975 with 8 by 10 opening, except when a colorized, polyvinyl chloride coating
is required then the Style shall be a Style 3.

The longitudinal edges of the wire mesh fabric shall have knuckled selvedges with
continuous selvedge wire as specified in ASTM A975.

Fence and Guardrail

9-16

9-16.4(3) Wire Rope

Wire rope shall be ¾-inch-diameter, independent wire rope class (IWRC) 6x19, extra
improved plow steel (EIP) wire rope galvanized in accordance with ASTM A1023. Each lot
of wire rope shall be accompanied by a Manufacturer’s Certificate of Compliance, a mill
certificate, and a test report showing the wire rope meets the minimum breaking force
requirements of ASTM A1023.

9-16.4(4) Hardware

Weldless steel rings shall be drop-forged steel and heat treated after forging; have a
single pull, working load limit of at least 10,000 lbs; and meet performance requirements
of Federal Specification RR-C-271D Type VI.

Thimbles required for all wire rope loops shall be standard weight, galvanized, and meet
performance requirements of Federal Specification FF-T-276b Type II.

Wire rope clips shall have drop-forged steel bases, be galvanized, and meet performance
requirements of Federal Specification FF-C-450 Type I Class 1.

9-16.4(5) Fasteners and Lacing Wire

Fasteners shall consist of 11 gauge high tensile steel. Lacing wire shall consist of 9 gauge,
zinc-coated steel wire conforming to ASTM A641.

9-16.4(6) Ground Anchors

Threaded bar ground anchors shall be deformed, continuously threaded, steel
reinforcement bars conforming to either

Section 9-07.2

Section 9-07.11

. Threaded bar

ground anchors shall be either epoxy-coated in accordance with

Sections 6-02.3(24)H

and

9-07.3

or galvanized after fabrication in accordance with ASTM A767 Class I.

Hollow-core anchor bars shall have continuous threads/deformations and be fabricated
from steel tubing conforming to ASTM A519. Couplers and nuts shall provide 100 percent
of the guaranteed minimum tensile strength of the hollow core anchor bars.

Bearing plates shall conform to ASTM A572 Grade 50 and shall be galvanized after
fabrication in accordance with AASHTO M 111. Nuts shall conform to either AASHTO
M 291 Grade B, hexagonal, or

Section 9-07.11

. Nuts shall be galvanized after fabrication

in accordance with AASHTO M 111 for plate washers and AASHTO M 232 for all other
hardware.

Grout for ground anchors shall be Grout Type 2 for Nonshrink Applications, conforming to

Section 9-20.3(2)

Concrete for soil anchor deadmen shall be either commercial concrete conforming to 8

Section 6-02.3(2)B

or Class 3000 conforming to

Section 6-02

Steel reinforcing bars for soil anchor deadmen shall conform to

Section 9-07.2

, and shall

be epoxy-coated in accordance with

Sections 6-02.3(24)H

and

9-07.3

Page 9-142

Fence and Guardrail

9-16.5 Vacant
9-16.6

Glare Screen

9-16.6(1) General

All material used in the construction of the fence shall be new. Iron or steel material
shall be galvanized or aluminum coated as specified. Imperfectly galvanized or aluminum
coated material, or material upon which serious abrasions of galvanizing or aluminum
coating occur, will not be acceptable.

9-16.6(2) Glare Screen Fabric

Glare screen fabric shall consist of diamond woven wire mesh. The fabric wire may
be 0.148-inch diameter aluminum alloy complying with the Aluminum Association
requirements for alloy 6061T94, or it may be 0.148-inch diameter (9-gage) iron or
steel wire which shall meet all of the requirements of ASTM A392 galvanized or ASTM
A491 for aluminum coated, except that galvanizing of Type 2 glare screen fabric shall
be not less than 0.8 ounce per square foot and shall be done before weaving. Aluminum
coating shall be Class II.

Type 1 glare screen mesh size shall be approximately a 1 inch diamond. Type 2 glare
screen mesh size shall be a maximum of 3½ inch vertical and 5½ inch horizontal. The
design shall permit the slats to be installed in a vertical position as shown in the Plans
without distortion of the slats.

9-16.6(3) Posts

Line posts for Types 1 and 2 glare screens shall be 2 inch inside diameter galvanized steel
pipe with a nominal weight of 3.65 pounds per linear foot. End, corner, brace, and pull
posts for Type 1 Design A and B and Type 2 shall be 2½ inch inside diameter galvanized
steel pipe with a nominal weight of 5.79 pounds per linear foot. Intermediate pull posts
(braced line posts) shall be as specified for line posts.

The base material for the manufacture of steel pipes used for posts shall conform to the
requirements of ASTM A53, except the weight tolerance on tubular posts shall be applied
as provided below.

Posts provided for glare screen will have an acceptance tolerance on the weight per linear
foot, as specified, equal to plus or minus 5 percent. This tolerance will apply to each
individual post.

All posts shall be galvanized in accordance with AASHTO M 181, Section 32. The
minimum average zinc coating is per square foot of surface area. This area is defined as
the total area inside and outside. A sample for computing the average of mass of coating
is defined as a 12-inch piece cut from each end of the galvanized member.

Fence and Guardrail

9-16

9-16.6(4) Tension Wire

Top and bottom tension wire shall be 7 gage coil spring steel wire of good commercial
quality and shall have a zinc coating averaging 0.8 ounces per square foot of surface area.

9-16.6(5) Vacant

9-16.6(6) Tension Wire Attachments

All tension wire attachments shall be galvanized steel conforming to the requirements of
AASHTO M 232 unless otherwise specified. Eye bolts shall have either a shoulder or a
back-up nut on the eye end and be provided with an eye nut where needed or standard
hex nut and lock washer ⅜-inch diameter for tension wire and of sufficient length to
fasten to the type of posts used. Turnbuckles shall be of the shackle end type, ½-inch
diameter, with standard take-up of 6 inches and provided with ⅜-inch diameter pins.

9-16.6(7) Slats

9-16.6(7)A

Wood Slats

Wood slats shall be ⅜ by 2⅜ inch by the height designation of the fence. Material shall
be finished and treated cedar or redwood and shall be free from loose knots, cracks,
and other imperfections. A dimensional tolerance of plus or minus 1/16 inch in width or
thickness is allowed provided that the maximum space between slats does not exceed
¾ inch.

9-16.6(7)B

Plastic Slats

Plastic slats shall be ⅜ by 2⅜ inch by the height designation of the fence. They shall
be manufactured from tubular polyethylene color pigmented material consisting of
high-density virgin polyethylene and color pigments, designed to retard ultraviolet
penetration. The material shall have a minimum wall thickness of 0.0030 inch plus or
minus 0.0003 inch and shall remain flexible without distortion and without becoming
brittle through a temperature range of -70ºF to + 250ºF. Tensile strength shall be at least
3,600 psi and the melt index shall not exceed 0.25.

Plastic slats shall be retained in place by means of U-shaped retainer members at the
bottom and top of the fence. Retainer members shall be of the same material as the slats.

The color for plastic slats will be approved by the Engineer from samples submitted by the
Contractor or supplier.

Page 9-144

Fence and Guardrail

9-16.6(8) Fittings

Fittings shall be malleable cast iron or pressed steel and galvanized in accordance with the
requirements of AASHTO M 232.

Fittings for any particular fence shall be those furnished by the manufacturer of the fence.

9-16.6(9) Fabric Bands and Stretcher Bars

Fabric bands shall be ⅛ inch by 1-inch nominal. Stretcher bars shall be 3/16 inch by ¾ inch
nominal or 5/16 inch diameter round bar nominal 5/16 inch diameter round stretcher bar shall
be used with Type 1. Nominal shall be construed to be the area of the cross section of
the shape obtained by multiplying the specified width by thickness. A variation of minus
5-percent from this theoretical area shall be construed as “nominal” size. All shall be
galvanized to meet the requirements of ASTM F626.

9-16.6(10) Tie Wire and Hog Rings

Tie wire shall be 9-gage aluminum wire complying with the ASTM B211 for alloy
1100 H14 or 9-gage galvanized wire meeting the requirements of AASHTO M 279.
Galvanizing shall be Class 1.

Hog rings shall be 12-gage galvanized steel wire.

Flexible Guide Posts

9-17

Flexible Guide Posts

9-17.1 General

Flexible guide posts shall be made of a flexible, nonwarping, nonmetallic, durable
plastic material; shall be resistant to damage due to impact, ultraviolet light, ozone,
hydrocarbons, and other effects of atmospheric weathering; shall resist stiffening
with age; and shall exhibit good workmanship and be free of burns, discoloration,
contamination and other objectionable marks or defects that affect appearance or
serviceability. The 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, galvanize in accordance with AASHTO M111. The 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. The 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

Standard Plans

. Appropriate

holes shall be provided for fastening the guide post to the guard rail post.

The material composition of flexible guide posts subsequently furnished shall not vary
from that of the samples upon which the State Materials Laboratory pre-approval is
based. If analysis by the Materials Laboratory determines there is a change in material
composition, such change shall constitute grounds for rejection and/or removal from the
Qualified Products List.

The 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. The letters shall be solvent
resistant, a minimum of ¼ inch in height, and permanently affixed to the post.

Unless otherwise specified, the color of the guide post shall be white or brown as
indicated in the Plans.

The reflective panel on a flat or elliptical guide post shall have a minimum width
of 3 inches facing traffic. The reflective sheeting shall have a minimum area of 24
square inches (3 by 8 inches). The reflective panel on a round guide post shall have an
8-inch minimum band of reflective sheeting visible for 360 degrees.

9-17.1(1) Dimensions

1. Flat Type – The post has a minimum width of 3 inches 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.

Page 9-146

Flexible Guide Posts

2. Tubular Type – The post is tubular or round/circular in shape. This allows for a

tubular post with a minimum diameter of 3 inches or a tubular post with a minimum
diameter of 2 inches with a flat or flattened oval surface at least 3 inches wide and
12 inches long measured from the top for mounting reflective sheeting.

3. Non-flat and Non-Tubular Type – This includes all post that do not fit into the two

types indicated above. This would include convex, w-shape, oval, and other post
designs. The post shall be wide enough to accept a 3-inch wide reflective sheeting.
Any curvature or rounding shall not significantly reduce the brightness value of the
reflective sheeting.

4. Surface Mount Guide Post Base – The base for surface mount guide posts shall be

approximately 8 inches in diameter with a maximum height of 2 inches.

5. Guide posts shall be of such length to provide the required mounting height above

the pavement surface in accordance with the

Standard Plans

9-17.1(2) Reflective Sheeting

Reflective sheeting for guide posts shall be Type III, IV, V, or VII conforming to

Section

9-28.12

. The reflective panel on a flat or elliptical guidepost shall have a minimum

width of 3 inches facing traffic. The reflective sheeting shall have a minimum area of 24
square inches (3 by 8 inches). The reflective panel on a round guidepost shall have an
8-inch minimum band of reflective sheeting visible for 360 degrees. Mount the reflective
sheeting on the guide post as detailed in the

Standard Plans

. Sheeting shall remain in place

during the life of the post.

9-17.2

Ultraviolet Resistance Test Procedure (Laboratory Test)

Two posts will be tested initially for tensile strength and elongation according to ASTM
D638 and again after 1,000 hours QUV weatherometer exposure (ASTM G53).

Six bow tie specimens shall be prepared from the delineator post samples submitted for
the purpose of ultraviolet (UV) exposure. The specimens shall be cycled at 1,000 hours in
a weatherometer in accordance with ASTM G53 (3 hr. 60C UV, 3 hr. 50C CON). Three of
each type shall be used for control purposes. The remaining three shall be subjected to
1,000 hours of UV exposure in the QUV weatherometer. Specimen dimensions conform
to those outlined below.

The laboratory test data shall summarize the tensile strength of each, and the average
tensile strength for both control and weathered samples. The data shall also summarize
the elongation of each, and the average elongation for both control and weathered
samples. The average values shall be used to show the percent change in tensile
and elongation.

9-17.2(1) Acceptance

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

Flexible Guide Posts

9-17

9-17.3

Field Impact Test Procedure

Sample size of eight units will be tested the following way:

Flexible Ground Mounted Posts

Eight flexible ground mounted posts installed by the manufacturer (four installed
manually and four installed mechanically). The delineators will be hit ten times (four
posts for glancing bumper hits and four posts for wheel hits). A standard sedan with a
bumper height of approximately 18 inches while traveling at a speed of 55 ± 2 mph will
be used for impact testing. Five of the impacts will be at an ambient temperature of 32
± 5°F and the remaining five impacts at an ambient temperature of 85 ± 5°F. The test
vehicle shall impact four of the posts at an angle perpendicular to the front of the post
and shall impact the remaining posts at an angle of 25 degrees clockwise from the angle
perpendicular to the front of the posts. The same test samples will be used for the ten
hits. Two flexible posts will be used for weatherometer testing. A glancing hit is defined
as one on the bumper near the vehicle headlight. The delineators shall be installed a
minimum of eight hours prior to being hit.

Flexible Surface Mounted Posts

Eight flexible surface mounted posts installed by the manufacturer will be hit ten times
(four posts for glancing bumper hits and four posts for wheel hits). A standard sedan with
a bumper height of approximately 18 inches while traveling at a speed of 55 ± 2 mph will
be used for impact testing. Five of the impacts will be at an ambient temperature of 32
± 5°F and the remaining five impacts at an ambient temperature of 85 ± 5°F. The test
vehicle shall impact four of the posts at an angle perpendicular to the front of the post
and shall impact the remaining posts at an angle of 25 degrees clockwise from the angle
perpendicular to the front of the posts. The same test samples will be used for the ten
hits. Two flexible posts will be used for weatherometer testing. A glancing hit is defined
as one on the bumper near the vehicle headlight. The delineators shall be installed a
minimum of eight hours prior to being hit.

9-17.3(1) Test Observations

Inspect each post after each impact and document the following:
1.  Any splits, cracks, breaks, or other forms of deformation or distress;
2.  The percent list to vertical 2 minutes after each impact;
3.  The approximate percentage of the reflective area that is damaged after each impact

to an extent it no longer performs as intended;

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

and bases. The testing agent will document any special equipment or techniques
required for installing or removing the posts and bases.

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

mounted flexible delineator post that would be of interest to the states;

6. Type of soil and impact surface.

Page 9-148

Flexible Guide Posts

9-17.3(2) Acceptance

A failure is defined as any of the following:
1. A minimum of 50 percent of the reflective sheeting shall be retained undamaged. An

area of damage greater than 50 percent is considered a failure.

2. If the guide post leans more than 10 degrees from vertical it is considered a failure.
3. Any cracking, other than surface cracking evident on only one face of the post, is

considered a failure.

4. Pullout in excess of 3 inches is considered a failure.

At least six of the guide posts must pass each criteria in the 55 ± 2 mph series of impacts
to be acceptable.

9-17.4 Pre-approval

In order for a particular model of flexible guide post to become preapproved, the
following conditions must be met:
1. The manufacturer must submit a written request for pre-approval along with

samples for each model to be tested to: State Materials Engineer, Department of
Transportation Materials Laboratory, PO Box 47365, Olympia, WA 98504-7365.
Requests shall identify the model for which approval is being requested. Samples
shall be complete with reflective panel attached, and shall be accompanied by the
manufacturer’s written installation procedures.

2. The guide posts will be field impact tested by the State Materials Laboratory to

verify compliance with these Specifications.

3. In lieu of State Materials Laboratory testing, the Lab will accept the results of

preapproved testing performed by the National Transportation Product Evaluation
Program (NTPEP), the manufacturer, or other agencies under the following
conditions:
a. The State Materials Laboratory is informed of the preapproval testing

sufficiently in advance in order to attend and observe. Attendance will be at the
discretion of the Materials Laboratory.

b. The results of the testing shall be reported in sufficient detail to enable the

State Materials Laboratory to evaluate compliance with these Specifications.

4. The manufacturer must submit a certified test report, including test data developed

by an approved testing laboratory, which demonstrates that the guide post complies
with the requirements of these Specifications. Certified test data supplied by the
manufacturer shall be subject to verification by appropriate tests conducted by the
State Materials Laboratory.

Frequency of field testing, evaluation, and pre-approval updating shall be at the sole
discretion of the State Materials Laboratory.

Precast Traffic Curb

9-18

Precast Traffic Curb

9-18.1

Precast Traffic Curb

9-18.1(1) Aggregates and Proportioning

The cement, fine and coarse aggregate, and reinforcing steel to be used in the
manufacture of precast concrete traffic curb shall meet the following requirements:
1. Portland cement or blended hydraulic cement shall conform to the requirements

Section 9-01

except that it may be Type I portland cement conforming to

AASHTO M 85.

2. Aggregates shall conform to the requirements of

Section 9-03

except that they shall

be uniformly graded up to a maximum size of ⅜ inch and shall contain sufficient fine
fractions to permit securing the type of surface finish specified herein. The aggregate
shall be approved by the Materials Laboratory before it is used.

3. Reinforcing steel shall conform to the requirements of

Section 9-07.1

4. The cement concrete mix shall be composed of not less than one part portland

cement to approximately two parts of fine aggregate and 3¼ parts of coarse
aggregate adjusted to secure proper workability. The Contractor will be allowed to
use a different concrete mix if approved by the Engineer, provided that it develops
not less than 4,000 psi compressive strength when tested at the age of 28 days.

9-18.1(2) Mixing

The mixers shall be kept in good repair and be equipped with an automatic timing device
and a positive device for regulating the quantity of water added to each batch. Such a
device must be approved by the Engineer before use.

After all materials, including water, have been placed in the mixer, the materials shall be
mixed for a period of not less than 1¾

minutes, or as much longer as may be necessary to

produce a thorough and uniform mixture of the concrete. No water shall be added to any
batch after the completion of the initial mixing period. Each batch of concrete shall be
completely emptied from the mixer before placing more materials in it. A batch which has
not been placed within 30 minutes from the time water was first added shall not be used.

The amount of water in the concrete shall be kept at a minimum consistent with the
manufacture of dense curb, free from air bubbles and surface defects in excess of the
tolerance limits specified.

Page 9-150

Precast Traffic Curb

9-18.1(3) Forms

Forms shall be of concrete or steel. The use of forms or molds made of plaster of paris,
wood, or other absorptive material will not be permitted.

Bulkheads shall be tight fitting so that there is no leakage of mortar between the
bulkhead and form.

The materials and methods used for lubricating the forms shall be such that they will not
result in discoloration of the curb at any time. A minimum quantity of lubricant shall be
used and all excess lubricant shall be removed.

9-18.1(4) Placing Concrete

The concrete shall be consolidated by external vibration, or by other means if approved by
the Engineer, to produce a dense concrete throughout, having a minimum of air bubbles
and honeycombing.

Reinforcing steel shall be placed and maintained in its proper position as shown in detail
drawings.

Curb or buttons shall not be manufactured in an atmospheric temperature of less than
50ºF.

9-18.1(5) Removal of Forms

The curb shall be removed from the molds or forms in accordance with the instructions or
by some other method acceptable to the Engineer.

The loosening of the curb from the molds shall be carefully performed to avoid excessive
shock and straining of the curb. When, in the opinion of the Engineer, undue shock is
required to remove the curb from the molds, the stripping operation shall be deferred
until such time as the curb may be removed without breakage.

9-18.1(6) Curing Concrete

Immediately after the concrete has been placed and consolidated in the mold, each unit
shall be placed in a curing room fitted with water sprays and maintained at a relative
humidity of not less than 90 percent and a temperature of not less than 60ºF, nor more
than 100ºF. Each unit shall remain in the curing room for a period of not less than
10 days, except that if Type III cement is used, the period in the curing room may be
reduced to 5 days.

Precast Traffic Curb

9-18

9-18.1(7) Finish

The curb shall have a smooth, glassy finish on all exposed surfaces.

Excess honeycombing in the back of the curb may be cause for rejection of the curb.
Honeycombing areas in the back of the curb which, in the opinion of the Engineer, are not
detrimental to the curb need not be patched. The workmanship of the bottom finish shall
be such that no mechanical interlocking of the mortar bed and the curb bottom or anchor
groove will occur.

9-18.1(8) Surface Treatment

As soon as the units have been taken out of the curing room and thoroughly surface
dried to a depth of at least ¼ inch, two coats of a water repellent compound, meeting the
requirements of

Section 9-18.4

, shall be brush applied. When the first coat has dried, the

second coat of water repellent compound shall be applied.

9-18.1(9) Dimensions and Shape

The curb shall conform to the dimensions and shape shown in the Plans within a
tolerance of ¼ inch in length and ⅛ inch in alignment.

9-18.1(10) Curb Lengths

Curb lengths shall be in accordance with the

Standard Plans

, except in special cases where

different lengths are specified. Circular curbing shall be made only for such radii as called
for in the detail plans.

9-18.1(11) Defective Curb

Not more than 2 percent of the top area in any one piece of curb shall be defective, and
not more than 5 percent of the total length of the top corners of reflecting faces in any
one piece of curb shall be broken or rounded. There shall be not more than 50 holes
in any linear foot of curb. All curb having defects in excess of any of the above will be
rejected immediately upon inspection after removal from the forms. However, failure to
reject the curb at that time will not ensure its final acceptance. Ninety percent of the curb
laid shall not have more than 10 percent of the maximum allowable number of defects
specified above.

An air hole shall be defined as any hole ⅛ inch or larger in diameter or depth.

All defects within the limits permitted, apparent upon removal of forms, shall be repaired
immediately.

The sum of the length of the lines of discoloration caused by a cracked mold in any one
piece of curb shall not exceed 50 percent of the length of the curb, and the maximum
length of any single line of discoloration shall not exceed 18 inches. 75 percent of the
curb laid shall be entirely free from lines of discoloration. The employment of heat to
obliterate lines of discoloration will not be permitted. The process used to obliterate lines
of discoloration shall be subject to the approval of the Engineer.

Page 9-152

Precast Traffic Curb

The repairing of molds which are chipped or broken shall be done in a manner that the
broken or chipped areas will not be apparent on the curb made in those molds.

All curb in which surface checking develops during the first five days after manufacture
will be rejected.

Hidden air holes at or immediately below the exposed surface of the curb, in excess of the
limits specified that are disclosed by testing the surface by means of a rubber hammer will
be cause for rejection of the curb.

All curb in which cracking is in evidence immediately after removal from the molds will
be rejected. A crack is defined as any separation of the concrete of a continuous length
greater than 3 inches.

All curb which varies in dimensions, alignment, or surface contour in excess of the
tolerance specified will be rejected.

Failure to comply with the Plans, Specifications, or instructions of the authorized
representative of the Contracting Agency in the manufacture and laying of any curb will
be cause for rejection of such curb.

9-18.1(12) Repairing Curb

Curb having defects which are not sufficient cause for its rejection shall be neatly repaired
immediately after removal from the molds in a manner subject to the approval of the
Engineer. However, no patching or other repairs shall be made without the permission of
the Engineer. Patches shall be undercut if, in the opinion of the Engineer, this operation is
necessary to achieve a satisfactory patch.

All holes larger than ¹/

-inch diameter in the exposed surface of acceptable curb or

buttons shall be filled with cement mortar.

9-18.1(13) Identification Marking

The date of manufacture, the length, and identification number corresponding to the
detail layout shall be marked in black paint on the back or end of each piece of curb.

Rejected curb shall be marked on the back or end surfaces in a practical and semi-
permanent manner to identify each cause of rejection.

9-18.1(14) Shipping

No unit of curb shall be shipped from the manufacturing plant prior to 21 days after
manufacture, except, however, that if Type III cement has been used, the units may be
shipped 14 days after manufacture.

Precast Traffic Curb

9-18

9-18.1(15) Sampling and Inspection

The Contractor shall submit, for the approval of the Engineer, an advance sample of
curb which shall be at least equivalent in color, surface texture, and bottom finish to
the standard as set forth in these Specifications. No repairing of any kind shall be done
on the advance sample. Upon approval, the advance sample shall be stored at the plant
or site of manufacture in a location readily accessible to the Inspector where there is
adequate daylight for examination. The advance sample shall be protected from damage
and discoloration and shall be used as a standard of comparison for color, surface texture,
and bottom finish for all curb manufactured. All curb furnished shall be equivalent in the
foregoing respects.

The inspection at the plant will be made just prior to shipment, at which time examination
will be made of the alignment, contour, color, cracks, surface damage or discoloration,
broken corners or edges, and any other defects which may have developed, and to check
the laboratory test reports for strength. However intermediate inspections may be made
to determine surface checking and hidden air holes if it is impractical to examine for these
defects at the final inspection.

9-18.2 Vacant
9-18.3 Vacant
9-18.4

Water Repellent Compound

The water repellent compound shall be a clear, penetrating type, silicone resin base
compound containing no filler or other material which will leave a film on the surface of
the masonry after it is applied. It shall be of such consistency that it can be applied readily
by brush or spray to the masonry at atmospheric temperature down to -20ºF.

The average absorption of three test specimens treated with the water repellent
compound, when tested in accordance with the methods used in the State Materials
Laboratory, shall not exceed 2 percent after being partially immersed in water for
72 hours immediately after curing.

The average moisture vapor transpiration (breathing) of three test specimens, when
tested in accordance with the methods used in the State Materials Laboratory, shall be
not less than 50 percent at 7 days.

The water repellent compound shall be approved by the State Materials Laboratory
before it is used.

9-18.5

Sodium Metasilicate

Sodium metasilicate shall comply with ASTM D537.

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 85