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Section 409

By Oscar Carter,2014-01-20 03:30
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Section 409

    Section 409. - ASPHALT SURFACE TREATMENT

    Construction Requirements

409.10 Fog Seal. Add the following after the first sentence:

Unless otherwise noted on the plans, dilute the specified emulsion one part water to one part

    emulsified asphalt.

    Measurement

409.14 Add the following:

Measure fog seal including water added for dilution.

Indicate a breakdown of total emulsion and water added on the load invoices supplied to the CO

    for payment.

    Section 409. ASPHALT SURFACE TREATMENT

    Delete the Section and substitute the following:

    Section 409. ASPHALT SURFACE TREATMENT

    Description

409.01 This work consists of constructing a single or multiple asphalt surface treatment with

    aggregate or precoated aggregate. This work also includes constructing an asphalt fog seal

    without aggregate.

Surface treatment aggregate designation is designated as shown in Tables 409-1, 409-2, and 409-

    3.

Provide emulsified asphalt grade CRS-2P meeting the requirements of Table 702-3.

    Material

409.02 Conform to the following Subsections:

    Aggregate 703.10

    Asphalt binder 702.01

    Blotter 703.13

    Emulsified asphalt 702.03(d)

    Construction Requirements

409.03 Qualifications. Submit the following information for approval at least 28 days before

    placement.

Companies and individuals involved with the placement of asphalt surface treatments must

    conform to the:

(a) Demonstrate satisfactory completion of at least 10 comparable projects.

(b) Provide Superintendent or Foremen experience in surface treatment construction on at least

    10 comparable projects.

    409.04 Composition. Submit the following information and samples for approval at least 21 days before placement:

    (a) Aggregate samples. 80 pounds from each stockpile produced and the gradation range represented by each.

(b) Aggregate gradation target values. The proposed percentage of each stockpile to be used

    and the proposed target value for each sieve size.

    (c) Asphalt samples. 2 1-quart samples of asphalt binder or emulsified asphalt from the same source and of the type to be used for the surface treatment.

    (d) Asphalt temperature. Apply asphalt at temperatures according to Table 702-1.

    (e) Spread rates. The proposed spread rate for the aggregate and asphalt material.

409.05 Equipment. Furnish equipment as follows:

(a) Asphalt distributor.

    (1) Capable of heating asphalt evenly.

    (2) Adjustable full circulation spray bar to 15-foot width.

    (3) Positive controls including tachometer, pressure gauge, volume measuring device, or

    calibrated tank to uniformly deposit asphalt over the full width within 0.02 gallons per square

    yard of the required rate.

    (4) Thermometer for measuring the asphalt temperature in the tank.

    (b) Rotary power broom. Furnish a minimum of two brooms both with the following capabilities:

    (1) Self-propelled.

    (2) Capable of controlling the vertical broom pressure.

    (c) Pneumatic-tire rollers. Furnish a minimum of two pneumatic-tire rollers both with the following capabilities:

    (1) Self-propelled.

    (2) Minimum compacting width - 5 feet.

    (3) Gross weight adjustable within the range of 200 to 360 pounds per inch of compaction

    width.

(d) Aggregate spreader.

    (1) Self-propelled.

    (2) Minimum of 4 pneumatic tires on 2 axles.

    (3) Positive controls to uniformly deposit the aggregate over the full width of asphalt within

    10 percent by mass of the required rates.

(e) Other equipment. Other equipment of proven performance may be used in addition to or in

    lieu of the specified equipment when approved by the CO. Provide two-way communication

    between the asphalt distributor and the aggregate spreader if the roadway alignment does not

    permit visual contact.

409.06 Surface Preparation. On existing asphalt surfaces, ensure that the surface is dry.

    Immediately before placing the layer, remove loose dirt and other objectionable material from

    the surface by approved methods. Fog seal patches using a slow setting emulsion diluted with an

    equal part water. Apply the diluted emulsion at a rate of 0.17 gallons per square yard.

On existing aggregate surfaces, prime the surface according to Section 411. Allow the primed

    surface to cure at least 5 days for cutback asphalt or 24 hours for asphalt emulsions. Ensure that

    the primed surface is dry for surface treatments using asphalt binder or slightly damp for surface

    treatments using emulsified asphalt.

409.07 Weather Limitations. Apply surface treatment or fog seal according to the following:

(a) Apply single or multiple asphalt surface treatments when:

     thth(1) Between June 15 and September 15 unless other dates are approved by the CO.

    (2) Ambient air temperature is above 68?F and rising and surface temperatures are between

    80?F and 140?F

    (3) Weather is not foggy or rainy, and when rain or temperatures below 40?F are not

    anticipated for at least 24 hours after application.

    (4) Winds are less than or equal to 10 miles per hour.

    (5) Complete surface treatment application at least 2 hours before sunset.

(b) Apply fog seal when:

    (1) Ambient air and surface temperatures are above 50?F and rising.

    (2) Weather is not foggy or rainy, and when rain or temperatures below 40?F are not

    anticipated for at least 24 hours after application.

    (3) Complete fog seal applications at least 2 hours before sunset.

409.08 Production Start-Up Procedures for Surface Treatments. At least 10 days before the

    start of constructing all surface treatments containing aggregate, arrange for a pre-surface treatment conference. Coordinate attendance with the CO and any applicable subcontractors. Be prepared to discuss or submit the following:

(a) Proposed schedule of operations.

    (b) List of all personnel involved in the production and construction of the work including equipment calibration, sampling, and testing.

    (c) List of equipment, quantity, and description to be used in the production and construction of the work.

(d) Proposed traffic control plan.

    (e) Discuss Section 153, minimum frequency schedule for process control sampling and testing (to be performed by the Contractor).

(f) Discuss Subsections 409.08; 409.09, and 409.10.

(g) Discuss spill prevention and safety contingency plan.

    Provide 7 days advance notice before constructing all asphalt surface treatments containing aggregate. Also use these start-up procedures when resuming production after termination due to nonconforming work.

    On the first day of placement of each surface treatment layer, or whenever there is a change in the surface texture or aggregate gradation, construct a minimum of three 50-foot control strips that are one-lane wide. Each control strip will have different application rates of emulsion and/or surface aggregate. The CO will indicate which strip of the will serve as the approved project control strip. Coordinate location of the control strips with the CO.

    Construct the control strip using material, lay-down, and compaction procedures intended for the remainder of the surface treatment. Cease production after construction of the control strip until the material and the control strip are evaluated and accepted.

    Acceptable control strips may remain in place and will be accepted as a part of the completed surface treatment.

Repeat the control strip process until an acceptable control strip is produced.

409.09 Asphalt Application. Calibrate the asphalt distributor spray bar height, nozzle angle,

    pump pressure and check the longitudinal and transverse spread rates daily, before start up, and

    as directed by the CO according to ASTM D 2995. If different asphalt distributors are used, calibrate each before use on the project. Ensure that the length of the spread is no more than can be covered with aggregate immediately after application. Document all calibration and application rates and provide to the CO at the end of each days production.

    Protect the surfaces of nearby objects to prevent spattering or marring. Spread building paper on the surface for a sufficient distance from the beginning and end of each application so the flow through the distributor nozzles may be started and stopped on the paper.

    Apply the asphalt uniformly with an asphalt distributor at the optimum application rate determined from the test strip. Move distributor forward at the proper application speed at the time the spray bar is opened. Stop application if any nozzles are plugged or if triple nozzle spray coverage is not occurring. Use care not to apply excess asphalt at the junction of spreads.

    Correct skipped areas or deficiencies. Remove and dispose of paper or other material used.

409.10 Aggregate Application. When using asphalt binder, the aggregate surface should be

    dry. When using emulsified asphalt, the aggregate surface should be moist. Verify aggregate stockpiles moisture daily during production with visual inspection.

    Apply the aggregate uniformly with an aggregate spreader immediately after the asphalt is applied at the optimum application rate determined from the test strip. Check and record spread rate daily, before start up, and as directed by the CO. Operate aggregate spreader so the asphalt is covered with the aggregate before wheels pass over it. During part-width construction, leave uncovered a strip of sprayed asphalt approximately 6 inches wide to permit an overlap of asphalt material.

    Immediately correct excesses and deficiencies by brooming or by the addition or removal of aggregate until a uniform texture is achieved. Use hand methods in areas not accessible to power equipment.

    When precoated aggregates are used, they may be mixed on the job or at a central mixing plant. Uniformly coat the aggregate with 1.0 to 2.0 percent residual asphalt, by weight of aggregate. Maintain the flow qualities of the precoated aggregate, so it is satisfactorily spread with an aggregate spreader.

    Operate rollers at a maximum speed of 5 miles per hour. Do not permit the aggregate to be displaced by pickup or sticking of material to the tire surface. Roll the surface to uniformly and thoroughly bond the aggregate over the full width. Complete rolling within 1 hour after asphalt is applied to the surface.

409.11 Fog Seal. A fog seal consists of applying slow-setting emulsified asphalt diluted with

    water onto an existing asphalt surface. Unless otherwise noted on the plans, dilute the specified emulsion one part water to one part emulsified asphalt. Apply the diluted emulsified asphalt according to Subsection 409.09 at a rate of 0.10 to 0.15 gallons per square yard depending on the condition of the existing surface. Allow the fog seal to penetrate undisturbed for at least 2 hours or until the emulsified asphalt breaks and is substantially absorbed into the existing surface. Then lightly cover remaining spots of excess asphalt with blotter according to Section 411 before opening the surface to traffic.

409.12 Single-Course Surface Treatment. A single-course surface treatment consists of

    applying asphalt material onto an existing surface immediately followed by a single, uniform

    application of aggregate. Apply the asphalt and aggregate according to Subsections 409.09 and

    409.10 at the approximate rates shown in Table 409-1. Application rates shown in Table 409-1

    should be used for estimating purposes only. The contractor shall determine aggregate and

    asphalt application rates that may fall outside the ranges shown in Table 409-1. Before curing,

    the emulsion should rise just below the top of the aggregate. After curing, embedment depth of

    the aggregate in the residual asphalt should be approximately 60% of the nominal maximum size.

    Determine the exact rates based on approved control strips.

Use a pilot car according to Section 635 to limit traffic speeds. During the initial 45 minutes

    after completion of rolling, limit the traffic speeds to 10 miles per hour. Limit traffic speeds to

    20 miles per hour for 24 hours.

Lightly broom the aggregate surface on the morning after construction. Maintain the surface for

    4 days by distributing blotter according to Section 411 to absorb any free asphalt and by

    repairing areas deficient in aggregate. Remove excess material from the surface using a rotary

    broom. Do not displace embedded material. Do not broom the surface where the air temperature

    is above 90?F.

    Table 409-1

    Approximate Quantities of Material for

    Single-Course Surface Treatment

    Estimated Estimated Estimated Nominal Quantity of Quantity of Aggregate Quantity of Maximum Emulsified Asphalt (1)(2)Gradation Aggregate Size of Asphalt Binder 2pounds/yd Aggregate 22Designation gallons/yd gallons/yd

    ? inch B 44 53 0.48 0.65 0.31 0.43 1A

    ? inch C 29 33 0.39 0.53 0.27 0.36 1B

    ? inch D 24 28 0.27 0.43 0.17 0.29 1C

    No. 4 E 18 24 0.22 0.29 0.14 0.19 1D

    Sand F 13 18 0.17 0.24 0.12 0.17 1E

    (1) See Table 703-7 for aggregate gradations. (2) Aggregate masses are for aggregates having a bulk specific gravity of 2.65, as

    determined by AASHTO T 84 and AASHTO T 85. Make proportionate corrections

    when the aggregate furnished has a bulk specific gravity above 2.75 or below 2.55.

409.13 Double and Triple-Course Surface Treatments. Double and triple-course surface

    treatments consist of applying multiple layers of asphalt and aggregate. Apply each asphalt and

    aggregate layer according to Subsections 409.09 and 409.10 and at the approximate rates shown

    in Table 409-2 or 409-3. Application rates shown in Table 409-2 and 409-3 should be used for

    estimating purposes only. The contractor shall determine aggregate and asphalt application rates

    that may fall outside the ranges shown in Tables 409-2 or 409-3. Determine the exact rates

    based on approved control strips.

Maintain the surface and limit traffic according to Subsection 409.11.

    No wait is required between surface treatment applications when using an asphalt binder. Wait

    at least 24 hours between applications when using emulsified asphalt.

    Table 409-2

    Approximate Quantities of Material for

    Double Course Surface Treatments

    Estimated Estimated Nominal Estimated Quantity of Quantity of Designation Maximum Aggregate Quantity of Emulsified Asphalt (1)(2)(Thickness) Size of Gradation Aggregate Asphalt Binder 2Aggregate pounds/yd 22gallons/yd gallons/yd

    2A (? inch)

    st1 Application ? inch D 29 39 0.27 0.39 0.17 0.27 nd2 Application No. 4 E 13 18 0.39 0.48 0.27 0.31

    2B (? inch)

    st1 Application ? inch C 33 44 0.39 0.48 0.27 0.31 nd2 Application No. 4 E 18 24 0.48 0.60 0.31 0.41

    2C (? inch)

    st1 Application ? inch B 44 53 0.43 0.60 0.29 0.41 nd2 Application ? inch D 24 29 0.60 0.70 0.41 0.46 (1) See Table 703-7 for aggregate gradations. (2) Aggregate masses are for aggregates having a bulk specific gravity of 2.65, as determined by

    AASHTO T 84 and AASHTO T 85. Make proportionate corrections when the aggregate furnished has

    a bulk specific gravity above 2.75 or below 2.55.

    Table 409-3

    Approximate Quantities of Material for

    Triple Course Surface Treatments

    Estimated Estimated Nominal Estimated Quantity of Quantity of Designation Maximum Aggregate Quantity of Emulsified Asphalt (1)(2)(Thickness) Size of Gradation Aggregate Asphalt Binder 2Aggregate pounds/yd 22gallons/yd gallons/yd 3A (? inch)

    st1 Application ? inch D 29 39 0.27 0.39 0.17 0.27 nd2 Application No. 4 E 13 18 0.31 0.43 0.22 0.29 rd3 Application Sand F 13 18 0.27 0.39 0.17 0.27 3B (? inch)

    st1 Application ? inch C 33 44 0.27 0.39 0.17 0.27 nd2 Application ? inch D 18 24 0.39 0.48 0.27 0.31 rd3 Application No. 4 E 13 18 0.27 0.39 0.17 0.27 3C (? inch)

    st1 Application ? inch B 39 50 0.31 0.43 0.22 0.29 nd2 Application ? inch D 24 29 0.39 0.48 0.27 0.31 rd3 Application No. 4 E 13 18 0.31 0.43 0.22 0.29 (1) See Table 703-7 for aggregate gradations.

    (2) Aggregate masses are for aggregates having a bulk specific gravity of 2.65, as determined by AASHTO

    T 84 and AASHTO T 85. Make proportionate corrections when the aggregate furnished has a bulk specific

    gravity above 2.75 or below 2.55.

409.14 Acceptance. Asphalt binder, and emulsified asphalt, will be evaluated under

    Subsections 106.03, 106.04 and 702.09. Furnish a production certification for the grade of

    asphalt binder or emulsified asphalt specified in Subsection 409.01.

Aggregate gradation for asphalt surface treatment will be evaluated under Subsection 106.05.

See Table 409-4 for sampling and testing requirements.

The upper and lower specification limits are equal to the calculated mean of all test results plus

    or minus the allowable deviations shown in Table 703-7, except as follows:

(a) If the calculated mean value for any tested sieve exceeds the maximum gradation value

    shown in Table 703-7, the upper specification is equal to the maximum gradation value plus the

    allowable deviation, and the lower specification is equal to the maximum gradation value minus

    the allowable deviation.

    (b) If the calculated mean value for any tested sieve is less than the minimum gradation value shown in Table 703-7, the upper specification is equal to the minimum gradation value plus the

    allowable deviation and the lower specification is equal to the minimum gradation value minus

    the allowable deviation.

Construction of asphalt surface treatment course will be evaluated under Subsections 106.02 and

    106.04.

Prime coat and blotter will be evaluated under Section 411.

    Measurement

    409.15 Measure the Section 409 items listed in the bid schedule according to Subsection 109.02 for each day’s production and the following as applicable.

Measure and provide temperature volume corrections for emulsified asphalt and asphalt binder to

    60?F.

Measure surface treatment aggregate in the hauling vehicle prior to stockpiling or prior to

    placement if not stockpiled.

Measure fog seal including water added for dilution. Indicate a breakdown of total emulsion and

    water added on the load invoices supplied to the CO for payment.

Measure blotter under Section 411.

    Payment

    409.16 The accepted quantities will be paid at the contract price per unit of measurement for the Section 409 pay items listed in the bid schedule except the aggregate surface treatment contract

price unit bid price will be adjusted according to Subsection 106.05. Payment will be full

compensation for the work prescribed in this Section. See Subsection 109.05.

    Table 409-4

    Sampling, Testing and Acceptance Requirements

    Material or Type of Acceptance Test Methods Sampling Point of Split Reporting Characteristic Category Property (subsection) Specifications Frequency Sampling Sample Time Aggregate Surface Measured and tested Gradation. See 1 per type & treatment for conformance Table 703-7 for AASHTO T 27 & Source of Yes, when Before using --- source of (1) aggregate (106.04 & 105) applicable T 11 Material requested in work material (source quality) sieves.

    (703.10) LA abrasion --- AASHTO T 96

    Sodium sulfate

    soundness loss --- AASHTO T 104

    (coarse & fine)

    Fractured faces --- ASTM D 5821

    Flat & elongated --- ASTM D 4791 particles

    Adherent coating --- ASTM D 5711

    Clay lumps & --- AASHTO T 112 friable particles

    Blotter Material Gradation. --- AASHTO T 27 Measured and tested (source quality) for conformance AASHTO T 87 & (703.13) Liquid limit --- (106.04 & 105) T 89

    Aggregate surface 1 per 4000 Gradation. See Production treatment square yards, Statistical Table 703-7 for AASHTO T 27 & belt or (1)aggregate I but not less Yes 24 hours (106.05) applicable T 11 spreader (production) than 8 total sieves. discharge samples (2)Asphalt binder Measured and tested

    (702.01) or for conformance 1 per tanker Point of 2 1-quart Emulsified (106.04) Quality --- Subsection 409.13 truck including shipment --- samples (2)asphalt trailer delivery

    (702.03)

    (1) Applies to each aggregate grade furnished.

    (2) Applied to each asphalt material furnished.

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