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

Bituminous Surface Treatment

5-02

5-02.3(2)B

Seal Coats

The existing bituminous surface shall be swept with a power broom until it is free from
dirt or other foreign matter. Hand push brooms shall be used to clean omissions of the
power broom. In addition to power and hand brooms, the use of other equipment may be
necessary to thoroughly clean the Roadway prior to the application of emulsified asphalt.
Berms created by the removal of dirt or other foreign matter shall be evenly distributed
over the fore slope.

Repair of existing pavement shall be done in accordance with

Section 5-04

. The HMA

in repaired areas shall be fog sealed. HMA repaired areas may require a second fog seal
depending on surface texture as required by the Engineer. The pavement surface shall be
dry prior to fog sealing.

5-02.3(2)C

Pavement Sealing – Fog Seal

Where shown in the Plans or directed by the Engineer, the Contractor shall apply a fog
seal. Before application of the fog seal, all surfaces shall be thoroughly cleaned of dust,
soil, pavement grindings, and other foreign matter. The existing pavement surface shall
be dry.

5-02.3(2)D

Soil Residual Herbicide

Where shown in the Plans, soil residual herbicide shall be applied in accordance with

Section 5-04

. Application of the BST shall begin within 24 hours after application of

the herbicide.

5-02.3(2)E

Crack Sealing

Where shown in the Plans, seal cracks and joints in the pavement in accordance
with

Section 5-04.3(4)A1

and the following:

1. Cracks ¼ inch to 1 inch in width – fill with hot poured sealant.
2. Cracks greater than 1 inch in width – fill with sand slurry.

Page 5-18

5-02.3(3) Application of Emulsified Asphalt and Aggregate

Upon the properly prepared Roadway surface, emulsified asphalt of the grade specified
in the Special Provisions shall be uniformly applied with distributors and specified
aggregates spread at the following rates:

Application Rate

Undiluted Emulsified Asphalt

(gal. per sq. yd.) Applied

Aggregate Size

Aggregate Application

Rate (lbs. per sq. yd.)

New Construction

First

Application

0.35-0.65

½ inch - No. 4

or ¾ inch - ½ inch

25-45

Second

Application

0.35-0.60

½ inch - No. 4

25-40

Choke Stone

N/A

No. 4 - 0

4-6

Seal Coats

⅝ inch – No. 4

Choke Stone

0.40-0.65

⅝ inch - No. 4

No. 4 - 0

25-45

4-6

½ inch – No. 4

Choke Stone

0.35-0.55

½ inch - No. 4

No. 4 - 0

20-35

4-6

⅜ inch – No. 4

0.35-0.55

⅜ inch - No. 4

20-30

Choke Stone

N/A

No. 4 - 0

4-6

The Engineer will determine the application rates. The second application of emulsified
asphalt shall be applied the next day, or as approved by the Engineer.

Longitudinal joints will be allowed at only the centerline of the Roadway, the center of the
driving lanes, or the edge of the driving lanes.

To ensure uniform distribution of emulsified asphalt and that the distributor is correctly
calibrated, the Contractor shall provide a minimum 1,000-foot test strip when beginning
a BST section.

To avoid gaps and ridges at transverse junctions of separate applications of emulsified
asphalt and aggregate, the Contractor shall spread sufficient building paper over the
treated surface to ensure that the distributor will be functioning normally when the
untreated surface is reached. If ordered by the Engineer, the joints shall be cut back
to a neat edge prior to placing the building paper.

Should ridges, overlaps, or gaps occur at transverse joints, the Contractor shall repair
the defects to the satisfaction of the Engineer. In lieu of repair the Engineer may elect
to accept the completed joints and will deduct from monies due or that may become
due the Contractor, the sum of $200 for each joint where the deviations described
above are found. Should longitudinal joints occur outside the centerline of the Roadway,
the center of the driving lanes, or the edge of the driving lanes, the Contractor shall repair
the defects to the satisfaction of the Engineer.

Bituminous Surface Treatment

5-02

All costs involved in making the corrections to defects described above shall be borne
by the Contractor and no payment will be made for this Work.

Omissions (skips) by the distributor or tire marks on the uncovered emulsified asphalt
shall be immediately covered by hand patching with the same grade of emulsified asphalt
and aggregate used on the project.

The area covered by any one spread of emulsified asphalt shall be no more than can be
covered with aggregate within 1 minute from the time of application upon any part of
the spread. If field conditions warrant, this time may be increased as designated by the
Project Engineer.

Unless otherwise designated by the Engineer, emulsified asphalt shall be spread toward
the source of aggregate to avoid injury to the freshly treated surface.

Before application to the Roadway, emulsified asphalt shall be heated to the following
temperatures or that recommended by the manufacturer:

Type and Grade

of Emulsified Asphalt

Distributor Temperature

Min. °F

Max. °F

New Construction and Seal Coats

CRS-1, CRS-2, CRS-2P

125

195

CMS-2, CMS-2S, CMS-2h

125

185

Fog Seal

CSS-1, CSS-1h

140

Before application of the fog seal, all surfaces shall be thoroughly cleaned of dust, soil,
pavement grindings, and other foreign matter. The fog seal emulsified asphalt shall be
CSS-1 or CSS-1h diluted with water at a rate of one part water to one part emulsified
asphalt unless otherwise approved by the Engineer. The fog seal shall be uniformly
applied to the pavement at a diluted rate of 0.10 – 0.18 gal/sy. The finished application
shall be free of streaks and bare spots.

Fog sealing shall be applied no sooner than 3 days, but no later than 14 days after new
construction or seal coat. If required, newly placed aggregates shall be swept prior to the
fog seal application. Rebrooming for fog seal applications shall be paid under “Additional
Brooming”, per hour as specified in

Section 5-02.5

5-02.3(4) Vacant

Page 5-20

Bituminous Surface Treatment

5-02.3(5) Application of Aggregates

All aggregate stockpiles shall be watered down to provide aggregates that are uniformly
damp at the time of placement on the Roadway.

After the emulsified asphalt has been spread evenly over the Roadway surface,
aggregates of the type specified shall be evenly applied to the Roadway surface
by spreader equipment.

The aggregate shall be spread in one operation in such a manner that an 8-inch strip
of emulsified asphalt is left exposed along the longitudinal joint to form a lap for the
succeeding applications of emulsified asphalt. If necessary, thin or bare spots in the
spread of aggregate shall be corrected immediately by re-spreading with the chip spreader
or by hand spreading the aggregate.

A minimum of three pneumatic tired rollers providing a minimum of two complete
coverages to the Roadway immediately behind the spreading equipment for the coarse
aggregate shall be required.

The maximum rate of roller travel shall be limited to 8 mph.

The Contractor shall apply choke stone to the Roadway with additional spreading
equipment immediately following the initial rolling of the coarse aggregate unless
otherwise specified in the Contract documents or specified by the Engineer. Excess
aggregate shall be removed from the Roadway. A minimum of one pass with a pneumatic
roller shall be made across the entire width of the applied choke stone.

The operation of trucks hauling aggregate from the stockpile shall be so regulated that no
damage, as determined by the Engineer, will result to the Highway or the freshly applied
asphalt surface.

The completed surface shall be allowed to cure and then broomed as soon as practical.

If brooming causes rock to be turned or if the Engineer determines that additional cure is
needed, the Contractor shall broom the Roadway when directed by the Engineer. If, after
completion of the initial brooming, the Engineer determines the need to remobilize for
additional brooming, the Contractor shall rebroom the areas designated by the Engineer.
The Contractor shall apply water for dust control during brooming operations when safety
or environmental concerns arise, or as otherwise determined by the Project Engineer.

The Contractor shall be held responsible for protecting all surface waters, riparian
habitats, or other sensitive areas that may be encroached upon by brooming operations.
Materials such as dirt, foreign material, or aggregates removed from these areas shall
become the property of the Contractor and shall be disposed of in accordance with

Section 2-03.3(7)

Bituminous Surface Treatment

5-02

The Contractor shall use a pickup broom in all curbed areas, on all bridges, within city
limits, within sensitive areas, and where shown in the Plans both before the application of
emulsified asphalt and during the final brooming operation. When the pickup broom does
not satisfactorily pickup the aggregate, manual methods shall be used. Materials collected
by the pick up broom shall become the property of the Contractor and shall be disposed
of in accordance with

Section 2-03.3(7)

Aggregates accumulated in intersections and driveways due to brooming operations
shall become the property of the Contractor and shall be disposed of in accordance with

Section 2-03.3(7)

The Contractor shall notify the Engineer when the brooming for each section is
considered complete. The Engineer will indicate acceptance or inform the Contractor
of deficiencies within 24 hours of notification.

5-02.3(6) Additional Emulsified Asphalt and Aggregate

If the application of emulsified asphalt or aggregate, or both, is insufficient or excessive
for the required results, the Engineer may require the Contractor to make an additional
application of one or both materials in accordance with these Specifications, or at the
direction of the Engineer. Additional emulsified asphalt or aggregate used will be paid
for at the unit Contract prices for the materials used.

5-02.3(7) Patching and Correction of Defects

Omissions by the distributor or damage to the treated surface of any coat shall be
immediately covered by hand patching with emulsified asphalt in adequate quantities.
Holes which develop in the surface shall be patched in the same manner as specified
in

Section 5-02.3(2)A

. All costs incurred by the Contractor, in coating omissions and

patching, shall be included in the unit Contract prices for the materials used.

Defects such as raveling, lack of uniformity, or other imperfections caused by faulty
workmanship shall be corrected and new Work shall not be started until such defects
have been remedied.

All improper workmanship and defective materials resulting from overheating, improper
handling or application, shall be removed from the Roadway by the Contractor
and be replaced with approved materials and workmanship at no expense to the
Contracting Agency.

If the Engineer determines a fog seal is necessary at any time during the life of the
Contract, the Contractor shall apply a fog seal. The CSS-1 or CSS-1h emulsified asphalt
may be diluted with water at a rate of one part water to one part emulsified asphalt unless
otherwise specified by the Engineer.

Page 5-22

Bituminous Surface Treatment

5-02.3(8) Progress of Work

The Contractor shall organize the Work so that no longitudinal joints shall remain open
overnight.

5-02.3(9) Protection of Structures

The Contractor shall be responsible for protecting monument covers, sewer lids, manhole
covers, water valve covers, drainage grates, inlets, railroad tracks, bridge handrails and
expansion joints, guardrails, curbs, road signs, guide posts, or other facilities from the
application of emulsified asphalt and aggregates. This protective effort is to include
uncovering these items the same working day that the completed BST or seal coat
construction has passed the protected locations. If needed, drainage inlets shall be
cleaned out immediately after final brooming is completed. All costs incurred by the
Contractor in necessary protective measures shall be included in the unit Contract prices
for the various Bid items of Work involved.

5-02.3(10) Unfavorable Weather

Emulsified asphalt shall not be applied to a wet Roadway. Subject to the determination of
the Engineer, emulsified asphalt shall not be applied during rainfall, sand or dust storms,
or before any imminent storms that might damage the construction. The Engineer will
have the discretion as to whether the surface and materials are dry enough to proceed
with construction.

The application of any emulsified asphalt to the Roadway shall be restricted to the
following conditions:
1. The Roadway surface temperature shall be at least 55ºF. The air temperature shall be

at least 60ºF and rising. The air temperature shall be not less than 70ºF when falling
and the wind shall be less than 10 mph as estimated by the Engineer.

2. The surface temperature shall be not more than 130º F or as otherwise determined

by the Engineer.

3. No emulsified asphalt shall be applied which cannot be covered 1 hour before

darkness. The Engineer may require the Contractor to delay application of emulsified
asphalt until the atmospheric and Roadway conditions are satisfactory.

4. Construction of bituminous surface treatments shall not be carried out before May

1 or after August 31 of any year except upon written order of the Project Engineer.

5-02.3(11) Temporary Pavement Markings

During bituminous surface treatment paving operations, temporary pavement markings
shall be maintained throughout the project. Temporary pavement markings shall be
installed on the Roadway that was paved that day. Temporary pavement markings shall be
in accordance with

Section 8-23

Bituminous Surface Treatment

5-02

5-02.4 Measurement

Processing and finishing will be measured by the mile to the nearest 0.01 mile along the
main line Roadway. All related supplemental Roadways and irregular shaped areas will be
incidental.

Emulsified asphalt of the grade or grades specified will be measured by the ton in
accordance with

Section 1-09

Asphalt for fog seal will be measured by the ton, before dilution, in accordance with

Section 1-09

Aggregate from stockpile for BST will be measured by the cubic yard in trucks at the point
of delivery on the Roadway.

Furnishing and placing crushed aggregate will be measured by the cubic yard in trucks at
the point of delivery on the Roadway, or by the ton in accordance with

Section 1-09.1

Additional brooming will be measured by the hour.

Water will be measured in accordance with

Section 2-07

5-02.5 Payment

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

“Processing and Finishing”, per mile.
The unit Contract price per mile for “Processing and Finishing” shall be full pay for
all costs to perform the specified Work including blading, scarifying, processing,
leveling, finishing, and the manipulation of aggregates as required. In the event the
Proposal does not include a Bid item for “Processing and Finishing” then all costs for
processing and finishing shall be included in other related items of Work.
“Emulsified Asphalt (_______)”, per ton.
The unit Contract price per ton for “Emulsified Asphalt (_______) shall be full pay for
all costs to perform the specified Work including furnishing, heating, hauling, and
spreading the emulsified asphalt on the Roadway.
“Asphalt for Fog Seal”, per ton.
The unit Contract price per ton for “Asphalt for Fog Seal” shall be full pay for all costs
to perform the specified Work for fog seal.
“Agg. from Stockpile for BST”, per cubic yard.
The unit Contract price per cubic yard for “Aggregate from Stockpile for BST” shall
be full pay for all costs to perform the specified Work including loading, transporting,
and placing the material in the finished Work.
“Furnishing and Placing Crushed (_______)”, per cubic yard.
“Furnishing and Placing Crushed (_______)”, per ton.

Page 5-24

Bituminous Surface Treatment

The unit Contract price per cubic yard or per ton for “Furnishing and Placing Crushed
(_______) shall be full pay for all costs to perform the specified Work including
furnishing, transporting, and placing the material in the finished Work.
“Additional Brooming”, per hour.
The unit Contract price per hour for “Additional Brooming” shall be full pay for all
costs to perform the specified Work including rebrooming the Roadway.
“Water”, per M gal.
Payment for “Water” shall be in accordance with

Section 2-07.5

If the Proposal does not include a Bid item for water, the Contractor shall dampen
stockpiled or furnished aggregate as required, and the cost thereof shall be included
in other related items of the Work.
Any incidental Work required to complete the bituminous surface treatment that is
not specifically mentioned as included with the Bid items above shall be performed
by the Contractor and shall be included in the unit Contract prices of the various
related Bid items.

Page 5-26

Hot Mix Asphalt

5-04

Hot Mix Asphalt

This

Section 5-04

is written in a style which, unless otherwise indicated, shall be

interpreted as direction to the Contractor.

5-04.1 Description

This Work consists of providing and placing one or more layers of plant-mixed hot mix
asphalt (HMA) on a prepared foundation or base, in accordance with these Specifications
and the lines, grades, thicknesses, and typical cross-sections shown in the Plans. The
manufacture of HMA may include additives or processes that reduce the optimum
mixing temperature (Warm Mix Asphalt) or serve as a compaction aid in accordance with
these Specifications.

HMA shall be composed of asphalt binder and mineral materials as required, and may
include reclaimed asphalt pavement (RAP) or reclaimed asphalt shingles (RAS), mixed in
the proportions specified to provide a homogeneous, stable, and workable mix.

5-04.2 Materials

Provide materials as specified in these sections:

Asphalt Binder

9-02.1(4)

Cationic Emulsified Asphalt

9-02.1(6)

Anti-Stripping Additive

9-02.4

HMA Additive

9-02.5

Aggregates

9-03.8

Reclaimed Asphalt Pavement (RAP)

9-03.8(3)B

Reclaimed Asphalt Shingles (RAS)

Mineral Filler

Recycled Material

Joint Sealants

Closed Cell Foam Backer Rod

9-04.2(3)A

5-04.2(1) How to Get an HMA Mix Design on the QPL

Comply with each of the following:

•

Develop the mix design in accordance with WSDOT

SOP 732

•

Develop a mix design that complies with Sections

9-03.8(2)

and

9-03.8(6)

•

Develop a mix design no more than 6 months prior to submitting it for QPL

evaluation.

•

Submit mix designs to the WSDOT State Materials Laboratory in Tumwater, including

WSDOT

Form 350-042

•

Include representative samples of the materials that are to be used in the HMA

production as part of the mix design submittal.

Hot Mix Asphalt

5-04

•

Identify the brand, type, and percentage of anti-stripping additive in the mix design

submittal.

•

Include with the mix design submittal a certification from the asphalt binder

supplier that the anti-stripping additive is compatible with the crude source and the

formulation of asphalt binder proposed for use in the mix design.

•

Do not include HMA additives that reduce the optimum mixing temperature or serve

as a compaction aid when developing a mix design or submitting a mix design for QPL

evaluation. The use of HMA additives is not part of the process for obtaining approval

for listing a mix design on the QPL. Refer to

Section 5-04.2(2)B

The Contracting Agency’s basis for approving, testing, and evaluating HMA mix designs
for approval on the QPL is dependent on the contractual basis for acceptance of the HMA
mixture, as shown in

Table 1

Table 1

Basis for Contracting Agency Evaluation of HMA Mix Designs for

Approval on the QPL

Contractual Basis for

Acceptance of HMA Mixture

[see

Section 5-04.3(9)

]

Basis for Contracting Agency

Approval of Mix Design for

Placement on QPL

Contracting Agency Materials

Testing for Evaluation of the

Mix Design

Statistical Evaluation

WSDOT

Standard Practice

QC-8

located in the WSDOT

Materials Manual

M 46-01

The Contracting Agency will

test the mix design materials

for compliance with Sections

9-03.8(2)

and

9-03.8(6)

Visual Evaluation

Review of

Form 350-042

for

compliance with Sections

9-03.8(2)

and

9-03.8(6)

)

The Contracting Agency

may elect to test the mix

design materials, or evaluate

in accordance with WSDOT

Standard Practice QC-8

, at its

sole discretion.

If the Contracting Agency approves the mix design, it will be listed on the QPL for 12
consecutive months. The Contracting Agency may extend the 12 month listing provided
the Contractor submits a certification letter to the Qualified Products Engineer verifying
that the aggregate source and job mix formula (JMF) gradation, and asphalt binder crude
source and formulation have not changed. The Contractor may submit the certification no
sooner than three months prior to expiration of the initial 12 month mix design approval.
Within 7 calendar days of receipt of the Contractor’s certification, the Contracting
Agency will update the QPL. The maximum duration for approval of a mix design and
listing on the QPL will be 24 months from the date of initial approval or as approved by
the Engineer.

Page 5-28

Hot Mix Asphalt

5-04.2(1)A

Mix Designs Containing RAP and/or RAS

Mix designs are classified by the RAP and/or RAS content as shown in

Table 2

Table 2

Mix Design Classification Based on RAP/RAS Content

RAP/RAS Classification

RAP/RAS Content

Low RAP/No RAS

0% ≤ RAP% ≤ 20% and RAS% = 0%

High RAP/Any RAS

20% < RAP% ≤ Maximum Allowable RAP

and/or

0% < RAS% ≤ Maximum Allowable RAS

Percentages in this table are by total weight of HMA.

See

Table 4

Section 5-04.2(1)A2

to determine the limits on the maximum amount RAP

and/or RAS.

5-04.2(1)A1 Low RAP/No RAS – Mix Design Submittals for Placement

on QPL

For Low RAP/No RAS mix designs, comply with the following additional requirements:
1. Develop the mix design with or without the inclusion of RAP.
2. The asphalt binder grade shall be the grade indicated in the Bid item name or as

otherwise required by the Contract.

3. Submit samples of RAP if used in development of the mix design.
4. Testing RAP or RAS stockpiles is not required for obtaining approval for placing these

mix designs on the QPL.

5-04.2(1)A2 High RAP/Any RAS – Mix Design Submittals for Placement

on QPL

For High RAP/Any RAS mix designs, comply with the following additional requirements:
1. For mix designs with any RAS, test the RAS stockpile (and RAP stockpile if any RAP is

in the mix design) in accordance with

Table 3

2. For High RAP mix designs with no RAS, test the RAP stockpile in accordance with

Table 3

3. For mix designs with High RAP/Any RAS, construct a single stockpile for RAP and

a single stockpile for RAS and isolate (sequester) these stockpiles from further
stockpiling before beginning development of the mix design. Test the RAP and RAS
during stockpile construction as required by item 1 and 2 above. Use the test data
in developing the mix design, and report the test data to The Contracting Agency on
WSDOT

Form 350-042

as part of the mix design submittal for approval on the QPL.

Account for the reduction in asphalt binder contributed from RAS in accordance with
AASHTO PP 78. Do not add to these stockpiles after starting the mix design process.

Hot Mix Asphalt

5-04

Table 3

Test Frequency of RAP/RAS During RAP/RAS Stockpile Construction

For Approving a High RAP/Any RAS Mix Design for Placement on

the QPL

Test Frequency

Test for

Test Method

•

1/1000 tons of RAP

(minimum of 10 per mix

design) and

•

1/100 tons of RAS

(minimum of 10 per mix

design)

Asphalt Binder Content and

Sieve Analysis of Fine and

Coarse Aggregate

FOP for AASHTO T 308

and

FOP for AASHTO T 30/T 11

“tons”, in this table, refers to tons of the reclaimed material before being incorporated into HMA.

4. Limit the amount of RAP and/or RAS used in a High RAP/Any RAS mix design by the

amount of binder contributed by the RAP and/or RAS, in accordance with

Table 4

Table 4

Maximum Amount of RAP and/or RAS in

HMA Mixture

Maximum Amount of Binder Contributed from:

RAP

RAS

40%

minus contribution of

binder from RAS

20%

Calculated as the weight of asphalt binder contributed from the RAP as

a percentage of the total weight of asphalt binder in the mixture.

Calculated as the weight of asphalt binder contributed from the RAS as

a percentage of the total weight of asphalt binder in the mixture.

5. Develop the mix design including RAP, RAS, recycling agent, and new binder.
6. Extract, recover, and test the asphalt residue from the RAP and RAS stockpiles to

determine the percent of recycling agent and/or grade of new asphalt binder needed
to meet but not exceed the performance grade (PG) of asphalt binder required by
the Contract.
a. Perform the asphalt extraction in accordance with AASHTO T 164 or ASTM

D 2172 using reagent grade solvent.

b. Perform the asphalt recovery in accordance with AASHTO R 59 or ASTM

D 1856.

c. Test the recovered asphalt residue in accordance with AASHTO R 29 to

determine the asphalt binder grade in accordance with

Section 9-02.1(4)

d. After determining the recovered asphalt binder grade, determine the percent

of recycling agent and/or grade of new asphalt binder in accordance with
ASTM D 4887.

Page 5-30

Hot Mix Asphalt

e. Test the final blend of recycling agent, binder recovered from the RAP and

RAS, and new asphalt binder in accordance with AASHTO R 29. The final
blended binder shall meet but not exceed the performance grade of asphalt
binder required by the Contract and comply with the requirements of

Section 9-02.1(4)

7. Include the following test data with the mix design submittal:

a. All test data from RAP and RAS stockpile construction.
b. All data from testing the recovered and blended asphalt binder.

8. Include representative samples of the following with the mix design submittal:

a. RAP and RAS.
b. 150 grams of recovered asphalt residue from the RAP and RAS that are to be

used in the HMA production.

5-04.2(1)B

Commercial HMA – Mix Design Submittal for Placement on QPL

For HMA used in the Bid item Commercial HMA, in addition to the requirements of

Section 5-04.2(1)

identify the following in the submittal:

1.  Commercial HMA
2.  Class of HMA
3.  Performance grade of binder
4.  Equivalent Single Axle Load (ESAL)

The Contracting Agency may elect to approve Commercial HMA mix designs
without evaluation.

5-04.2(1)C

Mix Design Resubmittal for QPL Approval

Develop a new mix design and resubmit for approval on the QPL when any of the
following changes occur. When these occur, discontinue using the mix design until after
it is reapproved on the QPL.
1.  Change in the source of crude petroleum used in the asphalt binder.
2.  Changes in the asphalt binder refining process.
3.  Changes in modifiers used in the asphalt binder.
4.  Changes in the anti-strip additive, brand, type or quantity.
5.  Changes to the source of material for aggregate.
6.  Changes to the job mix formula that exceed the amounts as described in item 2 of

Section 9-03.8(7)

, unless otherwise approved by the Engineer.

Hot Mix Asphalt

5-04

7. Changes in the percentage of material from a stockpile, when such changes exceed

5 percent of the total aggregate weight.
a. For Low RAP/No RAS mix designs developed without RAP, changes to

the percentage of material from a stockpile will be calculated based on the total
aggregate weight not including the weight of RAP.

b. For Low RAP/No RAS mix designs developed with RAP, changes to

the percentage of material from a stockpile will be calculated based on the total
aggregate weight including the weight of RAP.

c. For High RAP/Any RAS mix designs, changes in the percentage of material from

a stockpile will be based on total aggregate weight including the weight of RAP
(and/or RAS when included in the mixture).

Prior to making any change in the amount of RAS in an approved mix design, notify the
Engineer for determination of whether a new mix design is required, and obtain the
Engineer’s approval prior to implementing such changes.

5-04.2(2) Mix Design – Obtaining Project Approval

Use only mix designs listed on the Qualified Products List (QPL). Submit WSDOT

Form

350-041

to the Engineer to request approval to use a mix design from the QPL. Changes

to the job mix formula (JMF) that have been approved on other contracts may be
included. The Engineer may reject a request to use a mix design if production of HMA
using that mix design on any contract is not in compliance with

Section 5-04.3(11)D

and G for mixture or compaction.

5-04.2(2)A

Changes to the Job Mix Formula

The approved mix design obtained from the QPL will be considered the starting job mix
formula (JMF) and shall be used as the initial basis for acceptance of HMA mixture, as
detailed in

Section 5-04.3(9)

During production the Contractor may request to adjust the JMF. Any adjustments to the
JMF will require approval of the Engineer and shall be made in accordance with item 2 of

Section 9-03.8(7)

. After approval by the Engineer, such adjusted JMFs shall constitute the

basis for acceptance of the HMA mixture.

5-04.2(2)B

Using HMA Additives

The Contractor may, at the Contractor’s discretion, elect to use additives that reduce the
optimum mixing temperature or serve as a compaction aid for producing HMA. Additives
include organic additives, chemical additives, and foaming processes. The use of Additives
is subject to the following:

•

Do not use additives that reduce the mixing temperature in accordance with

Section 5-04.3(6)

in the production of High RAP/Any RAS mixtures.

•

Before using additives, obtain the Engineer’s approval using WSDOT

Form 350-076

to describe the proposed additive and process.

Page 5-32

Hot Mix Asphalt

5-04.3

Construction Requirements

5-04.3(1) Weather Limitations

Do not place HMA for wearing course on any Traveled Way beginning October 1

through March 31

of the following year, without written concurrence from the Engineer.

Do not place HMA on any wet surface, or when the average surface temperatures are less
than those specified in

Table 5

, or when weather conditions otherwise prevent the proper

handling or finishing of the HMA.

Table 5

Minimum Surface Temperature for Paving

Compacted Thickness (Feet)

Wearing Course

Other Courses

Less than 0.10

55°F

45°F

0.10 to 0.20

45°F

35°F

More than 0.20

35°F

5-04.3(2) Paving Under Traffic

These requirements apply when the Roadway being paved is open to traffic.
In hot weather, the Engineer may require the application of water to the pavement to
accelerate the finish rolling of the pavement and to shorten the time required before
reopening to traffic.
During paving operations, maintain temporary pavement markings throughout the
project. Install temporary pavement markings on the Roadway prior to opening to traffic.
Temporary pavement markings shall comply with

Section 8-23

5-04.3(3) Equipment

5-04.3(3)A

Mixing Plant

Equip mixing plants as follows:
1. Use tanks for storage and preparation of asphalt binder which:

•

Heat the contents by means that do not allow flame to contact the contents or

the tank, such as by steam or electricity.

•

Heat and hold contents at the required temperatures.

•

Continuously circulate contents to provide uniform temperature and consistency

during the operating period.

•

Provide an asphalt binder sampling valve, in either the storage tank or the supply

line to the mixer.

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 59