The Table of Contents for this section is available.

640-1 DESCRIPTION.

The work covered by this section consists of the construction of a asphalt plant mix binder course composed of a mixture of coarse and fine aggregates, asphalt cement, and mineral filler and other additives when required, properly laid upon a prepared surface, in accordance with these specifications and in conformity with the lines, grades, thickness, and typical sections shown on the plans.

640-2 MATERIALS.

All materials shall meet the requirements of Division 10 shown below:

Coarse aggregate Article 1012-1

Fine aggregate Article 1012-1

Mineral filler Article 1012-1

Stone screenings Article 1012-1

Natural sand Article 1012-1

Asphalt cement, Grade AC-20 (See Standard Special Provisions) Article 1020-2

Non-strip additive Article 1020-8

640-3 COMPOSITION OF MIXTURE.

(A) General Requirements:

A combination of graded coarse and fine aggregates will be required which will produce an acceptable mix. The coarse aggregate shall consist of standard size aggregates.

At least 1/2 of the fraction passing the No. 200 sieve shall be mineral filler or stone screenings.

The percentage of natural sand in Asphalt Concrete Binder Course, Type HDB shall not exceed 20 percent by weight of total aggregate in the mixture.

(B) Job Mix Formula:

A job mix formula will be established by the Engineer for the particular materials the Contractor proposes to use in accordance with Article 610­3. The job mix formula target values will be established such that when the tolerances (where applicable) are applied, the mixture values will be within the design criteria listed in Table 640.

** ASTM D 4867 "Effect of Moisture on Asphalt Concrete Paving Mixtures" as modified by the Department.

In addition of the requirements of Table 640, the amount of material between any adjacent sieves, except between the 1 inch and 3/4 inch sieves shall not be less than 4 percent.

Additives may be utilized to achieve the required tensile strength ratio, subject to approval by the Engineer.

(C) Requirements for Completed Plant Mix:

The completed plant mix shall conform to the job mix formula within the tolerances shown in Table 640.

When a mix has been tested and has been found to be outside of the design criteria, the Engineer may require the removal from the road of any of this mix which has been placed and which is represented by the test results. All such mix which has been removed shall be replaced with plant mix which is within the job mix formula and allowable tolerances at no cost to the Department.

640-4 CONSTRUCTION REQUIREMENTS.

The asphalt plant mix shall be produced, transported to the site, placed, and compacted in accordance with the applicable requirements of Section 610.

The asphalt plant mix shall be compacted to a density of at least 95% of the laboratory density as determined by the Marshall method of test.

Where the asphalt plant mix binder is utilized to widen an existing pavement by less than 4.0 feet and is not within the travel lane, the Engineer will waive the density requirements provided reasonable efforts are made to achieve density acceptable to the Engineer.

Density control and determination shall be as specified in Article 610­11.

No plant mix binder course shall be placed that will not be covered with surface course during the same calendar year or within 15 days of placement if the plant mix is placed in January or February. Failure of the Contractor to cover the plant mix as required above will result in the Engineer notifying the Contractor in writing to cover the plant mix with a sand seal. The sand seal shall be applied in accordance with the requirements of Section 660 except that Articles 660­3, 660­11, and 660­12 will not apply. This work shall be performed by the Contractor at no cost to the Department. In the event the Contractor fails to apply the sand seal within 72 hours after receipt of such notice, the Engineer may proceed to have such work performed with Department forces and equipment. The cost of such work performed by Department forces will be deducted from monies due or to become due to the Contractor.

640-5 METHOD OF MEASUREMENT.

The quantity of binder course to be paid for will be the actual number of tons of binder course which has been incorporated into the completed and accepted work. The binder course will be measured by being weighed in trucks on certified platform scales or other certified weighing devices.

640-6 BASIS OF PAYMENT.

The quantity of binder course, measured as provided in Article 640­5, will be paid for at the contract unit price per ton for "Asphalt Concrete Binder Course, Type H", and "Asphalt Concrete Binder Course, Type HDB".

Furnishing asphalt cement for the mix will be paid for as provided in Article 620­5 for "Asphalt Cement for Plant Mix".

Furnishing asphalt laboratory facilities will be paid for as provided in Article 615­3 for "Field Laboratory Rental, Asphalt Plant Mix".

Furnishing non-strip additive will be paid for as provided in Article 622­5 for "Non-Strip Additive".

The above prices and payments will be full compensation for all work covered by this section, including but not limited to producing, weighing, transporting, placing, and compacting the plant mix as specified in Section 610; furnishing the asphalt cement and all other material for the plant mix; furnishing and applying tack coat as specified in Section 605; furnishing scales; maintaining the binder course until final acceptance of the project; and making any repairs or corrections to the binder course that may become necessary.

Payment will be made under:

Asphalt Concrete Binder Course, Type H Ton

Asphalt Concrete Binder Course, Type HDB Ton