6 SEC 415_ogi.pdf

Section 415 — Asphaltic Concrete Open Graded Crack Relief Interlayer

Section 415—Asphaltic Concrete Open Graded Crack Relief Interlayer

415.1 General Description

This work includes constructing a bituminous plant produced Asphaltic Concrete Open Graded Crack Relief Interlayer (OGI) over the existing roadway surface. The mixture shall serve as asphaltic concrete leveling over irregular surfaces and provide mitigation for reflective cracking prior to the placement of the final surface pavement. The mixture shall conform to the lines, grades, thicknesses, typical sections and cross sections shown on the plans or established by the Engineer.

This section includes the requirements for Asphaltic Concrete Open Graded Crack Relief Interlayer mixtures regardless of the gradation of the aggregates, type and amount of bituminous material, or pavement use. Follow the requirements in Section 400, Section 402 and Section 828 for production and placement, materials, equipment, and acceptance plans except as noted or modified in this specification.

Acceptance of work is on a lot-to-lot basis according to the requirements of this Section, Section 400, Section 402 and Section 106.

415.1.01 Definitions

Asphaltic Concrete Open Graded Crack Relief Interlayer: an open graded mixture placed at a lift thickness that yields stone on stone contact that provides in-place air void content of 18 to 23 percent to mitigate existing cracking within asphaltic concrete pavements.

415.1.02 Related References

A. Standard Specifications Section 106—Control of Materials

Section 109—Measurement and Payment

Section 152—Field Laboratory Building

Section 400 – Hot Mix Asphaltic Concrete Construction

Section 402 – Hot Mix Recycled Asphaltic Concrete

Section 413—Bituminous Tack Coat

Section 800 – Coarse Aggregate

Section 802 - Aggregate for Asphaltic Concrete

Section 820 – Asphalt Cement

Section 828—Hot Mix Asphaltic Concrete Mixtures

Section 831 – Admixtures

Section 882 – Lime

Section 883 – Mineral Filler

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B. Referenced Documents

AASHTO T 209

AASHTO T 202

AASHTO T 49

AASHTO T 315

Department of Transportation Standard Operating Procedure (SOP) 27

Department of Transportation Standard Operating Procedure (SOP) 15

Department of Transportation Standard Operation Procedure (SOP) 40

GDT 38

GDT 73

GDT 83

GDT 114

GDT 119

GDT 125

GDT 126

GSP 15

GSP 21

QPL 1

QPL 2

QPL 7

QPL 26

QPL 39

QPL 41

QPL 45

415.1.03 Submittals

A. Invoices

Furnish formal written invoices from a supplier for all materials used in production of HMA when requested by Department. Show the following on the Bill of Lading:

• Date shipped

• Quantity in tons (megagrams)

• Included with or without additives (for asphalt cement)

Purchase asphaltic cement directly from a supplier listed on Qualified Products List 7 and provide copies of Bill of Lading at the Department’s request.

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B. Paving Plan Before starting asphaltic concrete construction, submit a written paving plan to the Engineer for approval. Include the following on the paving plan:

• Proposed starting date

• Location of plant(s)

• Rate of production

• Average haul distance(s)

• Number of haul trucks

• Paver speed feet (meter)/minute for each placement operation

• Mat width for each placement operation

• Number and type of rollers for each placement operation

• Sketch of the typical section showing the paving sequence for each placement operation

• Electronic controls used for each placement operation

• Temporary pavement marking plan

If staged construction is designated in the plans or contract, provide a paving plan for each construction stage.

If segregation is detected, submit a written plan of measures and actions to prevent segregation. Work will not continue until the plan is submitted to and approved by the Department.

C. Job Mix Formula Submit to the Engineer a written job mix formula proposed for each mixture type to be used based on an approved mix design. Furnish the following information for each mix:

• Specific project for which the mixture will be used

• Source and description of the materials to be used

• Mixture I.D. Number

• Proportions of the raw materials to be combined in the paving mixture

• Single percentage of the combined mineral aggregates passing each specified sieve

• Single percentage of asphalt by weight of the total mix to be incorporated in the completed mixture

• Single temperature at which to discharge the mixture from the plant

• Theoretical specific gravity of the mixture at the designated asphalt content

• Name of the person or agency responsible for quality control of the mixture during production

Do the following to have the formulas approved in accordance with SOP 40 Approval of Contractor Job Mix Formulas and to ensure their quality:

1. Submit proposed job mix formulas for review at least two weeks before beginning the mixing operations.

2. Do not start hot mix asphaltic concrete work until the Engineer has approved a job mix formula for the mixture to be used. No mixture will be accepted until the Engineer has given approval.

3. Provide mix designs for all Asphaltic Concrete Open Graded Crack Relief Interlayer mixtures to be used.

4. After a job mix formula has been approved, assume responsibility for the quality control of the mixtures supplied to the Department according to Subsection 106.01, Source of Supply and Quantity of Materials.

D. Quality Control Program Submit a Quality Control Plan to the Office of Materials and Testing for approval. The Quality Control Program will be included as part of the certification in the annual plant inspection report.

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415.2 Materials

The requirements established in Section 400 are to be followed for Asphaltic Concrete Open Crack Relief Interlayer production and placement, materials, equipment, and acceptance plans except as noted or modified in this specification.

Ensure that materials comply with the specifications listed in Table 1.

TABLE 1—MATERIALS SPECIFICATIONS

Material Subsection

Asphalt Cement, Grade Specified 820.2

Coarse Aggregates for Asphaltic Concrete 802.2.02

Fine Aggregates for Asphaltic Concrete 802.2.01

Mineral Filler 883.1

Heat Stable Anti-Stripping Additive 831.2.04

Hydrated Lime 882.2.03

Silicone Fluid (When approved by the Office of Materials and Testing) 831.2.05

Bituminous Tack Coat: PG 58-22, PG 64-22, PG 67-22 820.2

Hot Mix Asphaltic Concrete Mixtures 828

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415.2.01 Mix Design Requirements

The Open Graded Crack Relief Interlayer Mixture shall be formulated to contain approximately 18 to 23 percent in-place air voids after compaction. Use approved mixtures that meet the following mixture control tolerances and design criteria:

TABLE 2 – ASPHALTIC CONCRETE OPEN GRADED CRACK RELIEF

INTERLAYER MIXTURE DESIGN AND CONTROL

Sieve Size

Mixture Control

Tolerance, Design Gradation Limits, % Passing

Open Graded Crack Relief Interlayer

3/4 in. (19 mm) sieve ±0.0 100

1/2 in. (12.5 mm) sieve ±6.1 80 - 100

3/8 in. (9.5 mm) sieve ±5.6 40 - 65

No. 4 (4.75 mm) sieve ±5.7 10 - 25

No. 8 (2.36 mm) sieve ±4.6 2 - 10

No. 200 (75 µm) sieve ±2.0 2 - 5

Range for % AC ±0.4 4.50 – 5.25

Class of stone (Section 800) “A” only

Drain-down (AASHTO T305), % <0.3

Design optimum air voids (%) 20% ± 2%

Control Sieves used in Acceptance Schedule 3/8 in., No. 8 (9.5 mm, 2.36 mm) and Asphalt Cement

Notes:

1. Use only PG 64-22 or PG 67-22 asphalt cement (specified in Section 820).

2. Use no less than 1.0% hydrated lime regardless of aggregates group or source(s) used.

3. Ensure no more than 10 percent Recycled Asphalt Pavement (RAP) is used in Asphaltic Concrete Open Graded Interlayer mixtures.

4. Quality Acceptance Test Results for AC content deviating > ± 0.3 % from the approved Job Mix Formula (JMF) consistently over three Lots may subject the mix to a revised AC content on the project JMF at the discretion of the State Materials Engineer based on statistical trend.

5. Range for % AC is Original Optimum AC (OOAC) at 25 blow Marshall prior to the Corrected Optimum

AC (COAC) calculation detailed in SOP 2 (Appendix D).

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415.3 Construction Requirements

The requirements established in Section 400 are to be followed for asphaltic concrete mixture production and placement, materials, equipment, and acceptance plans except as noted or modified in this specification.

415.3.01 Personnel

General Provisions 101 through 150.

415.3.02 Construction

Asphaltic concrete plants that produce mix for Department use are governed by Quality Assurance for Hot Mix Asphaltic Concrete Plants in Georgia, Laboratory Standard Operating Procedure No. 27.

Follow requirements established in Section 400 for production and placement, materials, equipment, acceptance plans and adjustments except as noted or modified in this specification.

A. Apply a bituminous tack coat according to Section 413. The Engineer will determine the application rate, which must be within the limits of 0.06 gal/yd2 to 0.10 gal/yd2 (0.27 L/m2 to 0.45 L/m2) (residual asphalt cement).

B. The mix shall be produced and placed at a temperature of 250°F with a tolerance of ± 20°F.

C. Place the mix to a compacted lift thickness of 1-inch (25 mm). For construction purposes, the target thickness will be converted to spread rate based on the bulk specific gravity of the asphaltic concrete mixture being used as shown in the following equation:

Spread rate (lbs./yd2) = t * Gmb* 46.8 (Spread rate (kg/ m2) = t * Gmb) Where: t = Compacted lift thickness (inches, mm) Gmb= bulk specific gravity of the mix from the approved mix design

The spread rate shall be controlled within 10 lbs./yd2 (6 kg/m2).

D. Do not place mix at air temperatures below 50 °F (10 °C).

E. The mix shall be compacted in a manner to achieve 18 to 23 percent in-place air voids. Steel wheel rollers operating in static mode only will be used to seat the lift of Asphaltic Concrete Open Graded Crack Relief Interlayer mixture. Pneumatic tire rollers shall not be allowed on the Asphaltic Concrete Open Graded Crack Relief Interlayer mat.

415.4. Measurement

Asphaltic Concrete Open Graded Crack Relief Interlayer mixture, complete, in place and accepted, is measured in tons (megagrams). If the spread rate exceeds the upper limits outlined in Subsection 415.3.02.C by > 15 lbs./yd2, the mix in excess will not be paid for. If the rate of the spread is ≤ 10 lbs./yd2 than the lower limit, the deficient course is subject to correction by overlaying the entire lot. The mixture used for correcting deficient areas is paid for at the Contract Unit Price of the course being corrected and is subject to mixture control requirements established in Table 2

– Asphaltic Concrete Open Graded Crack Relief Interlayer Mixture Design and Control. After the deficient course has been corrected, the total spread rate for that lot is recalculated, and the mix in excess of the upper limits outlined in Subsection 415.3.02.C will not be paid for.

415.5 Payment

Asphaltic Concrete Open Graded Crack Relief Interlayer mix is paid for at the Contract Unit Price per ton (megagram).

Payment is full compensation for furnishing and placing materials including asphalt cement, hydrated lime, approved additives, and for cleaning and repairing, preparing surfaces, hauling, mixing, spreading, rolling, and performing other operations to complete the Contract Item.

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Payment will be made under:

Item No. 415 Asphaltic Concrete Open Graded Crack Relief Interlayer, group-blend, Including bituminous materials and hydrated lime

Per ton (megagram)

415.5.01 Adjustments

A. Materials Produced and Placed During the Adjustment Period

Follow requirements established in Section 400 for production and placement, materials, equipment, acceptance plans and adjustments except as noted or modified in this specification.

Asphaltic Concrete Open Graded Crack Relief Interlayer shall be granted an adjustment period for the first Lot or day, whichever is less, produced for the Contract. A new adjustment period shall not be granted for a change of producer, mix design or asphalt plant location. The adjustment period is provided to adjust or correct the mix and to establish the construction procedures and sequence of operations. Test the mixture in accordance with Section

400.3.06. Maintain the asphalt cement content and gradation within the limits provided in Table 2 – Asphaltic Concrete Open Graded Interlayer Mixture Design and Control. The Engineer will not use these test results in the acceptance for payment decision, but production and placement operations shall cease for failure to meet mixture control tolerances established in Table 2 – Asphaltic Concrete Open Graded Interlayer Mixture Design and Control.

415.5.02 Determine Lot Acceptance

The Engineer will accept the mixture based on visual inspection. The mixture shall be inspected for texture, segregation, bleeding, fat spots, raveling, delamination, tearing, targeted in-place air void content and slippage areas.

Remove and replace any areas determined to be unacceptable to the Engineer.

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