424Bituminous Surface Treatment

424.1General Description

This work includes placing one or more applications of bituminous material and aggregate on a previously prepared base or pavement. 424.1.01 Definitions • Single Surface Treatment: One application of bituminous material that is covered with aggregate. • Double Surface Treatment: A bituminous material application that is covered with aggregate of the size specified in the proposal followed by a second bituminous material application that is covered with a second specified size aggregate. • Triple Surface Treatment: A bituminous material application that is covered with a specified size aggregate followed by subsequent applications of bituminous material that are covered with successively smaller size nominal aggregates. 424.1.02 Related References

QPL 65 424.1.03 Submittals General Provisions 101 through 150.

424.2Materials

Select the bituminous material from any type and grade listed in the materials table below. Notify the Engineer at least 10 days before ordering the bituminous material. The Engineer must approve the bituminous material choice. For a list of latex sources, see QPL 65. Ensure that materials meet the requirements of the following Specifications: Material Section Asphalt Cement, Performance Grade PG 58-22 or PG 64-22* 820.2.01 Cationic Asphalt Emulsion, Grade CRS-2h or CRS-3* 824.2.01 Latex-Modified Cationic Asphalt Emulsion, Grade CRS-2L 824.2.02 * Use PG 64-22 or CRS-3 only at the Engineer’s direction. (See Subsection 424.3.05.B.) 461 461 461 461 461 461 461

The size and group of aggregates used in the surface treatment are specified in the Proposal under the appropriate Line Item. Do not use unconsolidated limerock unless provided for in the plans or proposal. Use Class B aggregates only where the surface treatment is used for shoulder construction or where it is to be overlaid with asphaltic concrete. Material Section Coarse Aggregate, Class A Crushed Stone or Crushed Slag, Group I or II 800.2.01 Fine Aggregate for Asphaltic Concrete* 802.2.01 *For sand seal application, use WA 10 washed screenings made from Group II aggregates. 424.2.01 Delivery, Storage, and Handling General Provisions 101 through 150.

424.3Construction Requirements

424.3.01 Personnel General Provisions 101 through 150. 424.3.02 Equipment Have the Engineer approve equipment types and quantities before using equipment on the Project. Ensure that the equipment used to construct the surface treatment: • Produces work that complies with the standards in this section • Is on the Project and in proper working order before construction begins and during construction.

The Department will inspect annually the aggregate spreader before it is used in the work. If the spreader is approved, the Department will attach an equipment certification sticker to the spreader. Use a self-propelled aggregate spreader that can apply aggregate at the desired rate uniformly and accurately without corrugation, overlaps, or excess deficient areas. Ensure that the spreader can spread courses to the required widths. Provide spreaders to promptly cover the full width of the asphalt application.

The Department will inspect annually the pressure distributor before it is used in the work. If the distributor is approved, the Department will attach an equipment certification sticker to the distributor. The pressure distributor should be equipped as follows:

evenly throughout the length of the spray bars. Ensure that it maintains a constant, uniform pressure on the nozzles.

0.04 to 1.0 gal/yd², ± 0.02 gal/yd² (0.18 to 4.53 L/m², ± 0.10 L/m²) up to 24 ft. (7.2 m) wide without atomization, streaking, or pulsation in the flow. 462 462 462 462 462 462 462

• A tachometer and thermometers to indicate the application rate and the temperature of the tank contents • Measuring devices to accurately indicate the amount of bituminous material, in gallons (liters), in the d istributor before and after each application • Full circulating spray bars that can be adjusted laterally to conform to a stringline and capable of v ertical and horizontal adjustment. • A positive shut-off control to prevent dripping bituminous material on the roadway • A distributor tank equipped with a sample valve in a safe and convenient location to obtain bituminous material samples

Ensure that heating equipment will heat and maintain the bituminous material uniformly at the temperature r equired. Provide an accurate thermometer.

Use self-propelled, tandem-type steel-wheeled rollers. The rollers shall weigh from 3 to 8 tons (3 to 7 Mg). Ensure that the roller weights within these limits can properly seat the aggregate without fracturing the aggregate p articles. Equip the roller drums with scrapers to prevent pick up of material. Combination rollers with pneumatic- tired wheels that can be alternated with a steel drum are permitted as a substitute for steel-wheeled rollers.

Use self-propelled, two axles, pneumatic-tired rollers with smooth-tread rubber tires aligned such that gaps between the tires on one axle are covered by the tires of the other axle. Equip the roller tires with scrapers and scrubbers to prevent pick up of material. Ensure that all tires are of the same size and ply rating and inflated to a mi nimum of 60 psi (415 kPa). Maintain tire pressure such that the difference in pressure between any two tires does not exceed 5 psi (35 kPa). Provide ballast as directed by the Engineer.

Provide at least one power broom and one power blower, or a combination power broom and blower that can r emove dust or loose materials from the road surface. 424.3.03 Preparation Firmly compact, finish, and prime new bases. Ensure that the bases conform to the lines, grades, and cross sections within the tolerances specified.

Use power brooms, power blowers, hand brooms, or other means to remove loose material, dust, dirt, clay, and other materials that prevent bituminous materials from adhering to the base. Take special care to clean the outer edges thoroughly. Where necessary, use a motor grader blade to remove excess material off the paving edge.

Check the condition of prime as follows:

the Engineer. 424.3.04 Fabrication General Provisions 101 through 150. 463 463 463 463 463 463 463

424.3.05 Construction

Apply bituminous surface treatment only between April 15 and October 15 and only when: • Ambient temperature has not been less than 45 ºF (7 ºC) for 48 hours immediately prior to application. • No forecast of ambient temperature less than 45 ºF (7 ºC) for 48 hours immediately following application. • Ambient temperature and road surface temperature is at least 60 ºF (16 ºC) and stable at the time of application. No exceptions are permitted except as authorized by the Engineer. Do not apply asphalt cement to a wet surface. NOTE 1: When the relative humidity exceeds 80%, the ambient temperature exceeds 95 ºF (35 ºC), the pavement temperature exceeds 125 ºF (52 ºC) or the weather is windy or overcast, application of bituminous surface treatment will be at the discretion of the Engineer. NOTE 2: If hot mix asphaltic concrete will be applied over the surface treatment, the Engineer may waive the seasonal limitations providing that traffic is not permitted on the surface treatment until it is covered with hot mix asphaltic concrete.

Only use PG 64-22 or CRS-3 when directed by the Engineer due to a problem with excessive aggregate pickup during high ambient temperature.

The sequence of operations and quantities of materials are shown in Table 1, Table 2 and Table 3 ( Table 1a—metric, Table 2a—metric and Table 3a—metric). The Engineer will determine the material quantities to be used during construction and may change the minimum o r maximum application rate of any course during construction if the total quantities are within the amounts shown i n the Tables. Any deviation from the table quantities will require a negotiated adjustment of the Contract price autho rized by an approved Supplemental Agreement. When a single application of bituminous surface treatment is used as a Crack-Relief Interlayer, use the quantities of materials shown in Table 2 (Table 2a—Metric). When a sand seal application is Specified, use the quantities of materials shown in Table 3 (Table 3a—Metric). 464 464 464 464 464 464 464

Application Type Construction Single Double Triple Stone Sizes 1st #89 #7 #6 #7 #6 #6 #5 2nd #89 #7 #7 #7 3rd # 89 # 89 Control Tolerance Control Tolerance Control Tolerance 1st Application Bituminous Materials (gal/yd²) PG58-22 or PG64-22 ± .02 .17–.19 .18–.25 .22–.30 ± .02 .20–.27 .26–.34 ± .02 .20–.30 .24–.34 CRS-2h, CRS-3 ± .02 .20–.22 .21–.29 .25–.35 ± .02 .23–.32 .30–.40 ± .02 .23–.35 .28–.40 1st Application Stone (ft³/yd²) ± .03 .14–.18 .18–.26 .30–.42 ± .03 .18–.26 .30–.42 ± .03 .30–.42 .41–.53 2nd Application Bituminous Materials (gal/yd²) PG58-22 or PG64-22 ± .02 .18–.24 .24–.31 ± .02 .20–.27 .20–.27 CRS-2h, CRS-3 ± .02 .21–.28 .28–.36 ± .02 .23–.32 .23–.32 2nd Application Stone (ft³/yd²) ± .03 .14–.18 .18–.26 ± .03 .18–.26 .18–.26 3rd Application Bituminous Materials (gal/yd²) PG58-22 or PG64-22 ± .02 .18–.24 .18–.24 CRS-2h, CRS-3 ± .02 .21–.28 .21–.28 3rd Application Stone (ft³/yd²) ± .03 .14–.18 .14–.18 Total Bituminous Materials (gal/yd²) PG58-22 or PG64-22 ± .02 .17–.19 .18–.25 .22–.30 ± .03 .38–.51 .50–.65 ± .04 .58–.81 .62–.85 CRS-2h, CRS-3 ± .02 .20–.22 .21–.29 .25–.35 ± .03 .44–.60 .58–.76 ± .04 .67–.95 .72–1.0 Total Stone (ft³/yd²) ± .03 .14–.18 .18–.26 .30–.42 ± .04 .32–.44 .48–.68 ± .05 .62–.86 .73–.97 Notes:

the limits shown in Table 1, based on roadway and traffic conditions.

of the control tolerances shown for each application unless directed by the Engineer in accordance with No. 3 below.

limits for each course at no additional cost provided the combined total of materials is within the specified total minimum

and total maximum application rates for the combined total of all courses.

465465465465465465465

Bituminous Material Application (gal/yd

) Application Rate Control Tolerance

PG 58-22 or PG 64-22 .20 − .27 ± .02

CRS-2h, CRS-2L or CRS 3 .25 − .35 ± .02

Aggregate Application (ft

/yd

) Application Rate Control Tolerance

#89 .14 − .18 ± .02

#7 .18 − .26 ± .02

Notes:

• Target application rates for bituminous material and aggregate will be established by the Engineer within the

limits shown in Table 2.

• When single surface treatment stone size No. 89 or No. 7 is applied over a milled surface, the minimum

application rate for CRS-2h, CRS-2L or CRS 3 shall be 0.30 (gal/yd

) and for PG 58-22 or PG 64-22 shall be

0.22 (gal/yd

).

• Do not apply bituminous material or aggregate outside the specified minimum and maximum application rates

regardless of the control tolerances shown for each application.

• Maintain the control tolerances shown above or stop the work until the necessary corrections are made.

• Cover the single surface treatment Crack-Relief Interlayer with HMA Leveling on the same day.

Aggregates Application

Rate

(ft

/yd

)

Control

Toleran

ce

Bituminous Material Application

Rate

(gal/yd

)

Control

Toleran

ce

#6 .30 − .42 ± .02 CRS-2h, CRS-2L or CRS

.23 − .35 ± .02

PG 58-22 or PG 64-22 .20 − .30 ± .02

#7 .18 − .26 ± .02 CRS-2h, CRS-2L or CRS

.21 − .29 ± .02

PG 58-22 or PG 64-22 .18 − .25 ± .02

#89 .14 − .18 ± .02 CRS-2h, CRS-2L or CRS

.20 − .22 ± .02

PG 58-22 or PG 64-22 .17 − .19 ± .02

WA 10 Washed

Screenings

.10 − .14 ± .02 CRS-2h, CRS-2L or CRS

.10 − .25 ± .02

PG 58-22 or PG 64-22 .10 − .17 ± .02

Notes:

within the limits shown in Table 3, based on roadway and traffic conditions.

regardless of the control tolerances shown for each application unless directed by the Engineer in accordance with No.

3 below.

limits for each course at no additional cost provided the combined total of materials is within the specified total minimum

and total maximum application rates for the combined total of all courses.

466466466466466466466

Application Type Construction

Single Double Triple

Stone Sizes 1st #89 #7 #6 #7 #6 #6 #5

2nd #89 #7 #7 #7

3rd # 89 # 89

Control

Tolerance

Control

Tolerance

Control

Tolerance

1st Application

Bituminous

Materials (L/m²)

PG58-22 or PG64-

± .09 .77–.86 .82–1.13 1.00–

1.36

± .09 .91–1.22 1.18–

1.54

± .09 .91–

1.36

1.09–

1.54

CRS-2h, CRS-3 ± .09 .91–1.00 .95–1.31 1.13–

1.58

± .09 1.04–

1.45

1.36–

1.81

± .09 1.04–

1.58

1.27–

1.81

1st Application

Stone (m³/m²)

± .001 .005–

.006

.006–

.009

.01–.014 ± .001 .006–

.009

.01–

.015

± .001 .01–

.014

.014–

.018

2nd Application

Bituminous

Materials (L/m²)

PG58-22 or PG64-

± .09 .82–1.09 1.09–

1.40

± .09 .91–

1.22

.91–1.22

CRS-2h, CRS-3 ± .09 .95–1.26 1.27–

1.63

± .09 1.04–

1.45

1.04–

1.45

2nd Application

Stone (m³/m²)

± .001 .005–

.006

.006–

.009

± .001 .006–

.009

.006–

.009

3rd Application

Bituminous

Materials (L/m²)

PG58-22 or PG64-

± .09 .82–

1.09

.82–1.09

CRS-2h, CRS-3 ± .09 .95–

1.27

.95–1.27

3rd Application

Stone (m³/m²)

± .001 .005–

.006

.005–

.006

Total Bituminous

Materials (L/m²)

PG58-22 or PG64-

± .09 .77–.86 .82–1.13 1.00–

1.36

± .14 1.72–

2.31

2.26–

2.94

± .18 2.63–

3.67

2.81–

4.53

CRS-2h, CRS-3 ± .09 .91–1.00 .95–1.31 1.13–

1.58

± .14 1.99–

2.72

2.63–

3.44

± .18 3.04–

4.30

3.26–

4.53

Total Stone

(m³/m²)

± .001 .005–

.006

.006–

.009

.01–.014 ± .0013 .011–

.015

.016–

.024

± .0016 .021–

.029

.025–

.033

Notes:

within the limits shown in Table 1a, based on roadway and traffic conditions.

regardless of the control tolerances shown for each application unless directed by the Engineer in accordance with

No. 3 below.

specified limits for each course at no additional cost provided the combined total of materials is within the specified

total minimum and total maximum application rates for the combined total of all courses. 467467467467467467467

Bituminous Material Application (L/m

) Application Rate Control Tolerance

PG 58-22 or PG 64-22 .91 − 1.22 ± .09

CRS-2h, CRS-2L or CRS 3 1.13 − 1.58 ± .09

Aggregate Application (m

/m

) Application Rate Control Tolerance

#89 0.005 − 0.006 ± .0007

#7 .006 − .009 ± .0007

Notes:

• Target application rates for bituminous material and aggregate will be established by the Engineer within the limits

shown in Table 2a.

• When single surface treatment stone size No. 89 or No. 7 is applied over a milled surface, the minimum application

rate for CRS-2h, CRS-2L or CRS 3 shall be 1.36 (L/m

) and for PG 58-22 or PG 64-22 shall be 1.00 (L/m

).

• Do not apply bituminous material or aggregate outside the specified minimum and maximum application rates

regardless of the control tolerances shown for each application.

• Maintain the control tolerances shown above or stop the work until the necessary corrections are made.

• Cover the single surface treatment Crack-Relief Interlayer with HMA Leveling on the same day. 468468468468468468468

Aggregates Application

Rate

(m

/m

)

Control

Tolerance

Bituminous Material Application Rate

(L/m

)

Control

Toleranc

e

#6 0.0102 − 0.0142 ± .0007 CRS-2h, CRS-2L or

CRS 3

1.04 − 1.58 ± .09

PG 58-22 or PG 64-22 0.91 − 1.36 ± .09

#7 0.0061 − 0.0088 ± .0007 CRS-2h, CRS-2L or

CRS 3

0.95 − 1.31 ± .09

PG 58-22 or PG 64-22 0.81 − 1.13 ± .09

#89 0.0047 − 0.0061 ± .0007 CRS-2h, CRS-2L or

CRS 3

0.91 − 1.00 ± .09

PG 58-22 or PG 64-22 0.77 − 0.86 ± .09

WA 10 Washed

Screenings

0.0034 − 0.0047 ± .0007 CRS-2h, CRS-2L or

CRS 3

0.45 − 1.13 ± .09

PG 58-22 or PG 64-22 0.45 − 0.77 ± .09

Notes:

within the limits shown in Table 3a, based on roadway and traffic conditions.

regardless of the control tolerances shown for each application unless directed by the Engineer in accordance with

No. 3 below.

specified limits for each course at no additional cost provided the combined total of materials is within the specified

total minimum and total maximum application rates for the combined total of all courses.

Evenly heat the entire mass of bituminous material for each application under positive control. While the material is

being applied, maintain it within the specified temperature range.

The following are temperatures at which bituminous material shall be applied.

Bituminous Material Asphalt Cement CRS-2h CRS-3 CRS-2L

Application temperature °F (°C) 275–350

(135–177)

140–180

(60–82)

140–180

(60–82)

140–180

(60–82)

NOTE 1: Do not store emulsified asphalts at temperatures exceeding 150 °F (65 °C) for any extended time.

NOTE 2: Do not place bituminous surface treatment on fresh asphaltic concrete, except for paved shoulders,

until the asphaltic concrete has been in place at least 30 days. 469469469469469469469

The Engineer will designate the maximum area to which bituminous material may be applied at one time. Apply

the material as follows:

aggregate before beginning the next section.

Do not apply the bituminous material to the full width of the pavement unless the aggregate spreader can

immediately cover the full width of the applied material.

NOTE: Never allow bituminous material to chill, set up, dry, or reach a condition that impairs the

retention of cover aggregate before the aggregate is applied.

• Do not overlap the applications more than 4 in. (100 mm).

• Do not leave any area uncovered.

• Never allow excess quantities of bituminous materials to build up.

rate of bituminous material.

bituminous material that is sprayed or spilled on these structures.

a heavy paper or tight trough that is longer than the width of the treatment being applied. Place it to catch and

hold the surplus material.

and completely disposed of without damaging the Rights-of-Way.

Spread the aggregates as follows:

deficient areas.

excess aggregate before rolling.

470470470470470470470

Observe the following guidelines for rolling bituminous surface treatment:

requirements of Subsection 424.3.02.E.

aggregate particles.

Note: Unless a sufficient number of rollers are in operation to complete the above requirements, do not make

subsequent applications of bituminous material until rolling of the previous application is completed.

Use a revolving broom as necessary, supplemented by hand brooming, to remove or redistribute excess stone.

Sweep the completed surface treatment within the first three hours of the next available workday following

placement. Take care not to unseat bonded stone when sweeping.

Do not allow traffic on the surface treatment until the bituminous material has cured sufficiently to ensure that the

aggregate will not be loosened, dislodged, or whipped off by slow moving traffic.

Control traffic to speeds not exceeding 25 mph for a minimum of two hours after application of the seal stone and

until the Engineer permits the road to be opened to normal traffic speeds.

Use pilot vehicles to control traffic speeds.

424.3.06 Quality Acceptance

General Provisions 101 through 150.

424.3.07 Contractor Warranty and Maintenance

Maintain and protect the surface course as specified in Section 105 until the project has been accepted. Make repairs

as the Engineer directs. The cost of maintenance, protection, and repair is included in the Unit Prices Bid for the Item

for which they apply.

424.4Measurement

The area to be measured is the number of square yards (meters) of each type surface treatment completed

and accepted.

424.4.01 Limits

The length is measured along the surface. The width is specified on the Plans, plus or minus any authorized

changes. Irregular areas are measured by the surface square yard (meter) within the lines shown on the plans or

authorized changes. 471471471471471471471

424.5Payment

The accepted area of surface treatment will be paid for at the Contract Unit Price per square yard (meter) complete for

each type and stone size specified.

Payment will be made under:

Item No. 424 Single surface treatment stone size __ group__ Per square yard (meter)

Item No. 424 Double surface treatment stone size __ and __ group __ Per square yard (meter)

Item No. 424 Double surface treatment stone size __ and __ group __ with Seal

Sand __ and Latex-Modified Emulsion

Per square yard (meter)

Item No. 424 Double surface treatment stone size __ and __ group __ with Seal

Sand____

Per square yard (meter)

Item No. 424 Triple surface treatment stone sizes __, __ and __, group __ Per square yard (meter)) 472 472 472 472 472 472 472