Property Management Guide: Section 39 - Asphalt Concrete/Hot Mix

PROPERTY MANAGEMENT GUIDE:
SECTION 39 - ASPHALT CONCRETE

39-1 GENERAL

39-1.01 DESCRIPTION

This work shall consist of furnishing and mixing aggregate and asphalt binder at a central mixing plant, spreading and compacting the mixture, and furnishing and placing pavement reinforcing fabric, all as specified in these specifications and the special provisions.

Asphalt concrete is designated as Type A, Type B, or Open Graded.

Asphalt concrete base is designated as Type A or Type B. The type of asphalt concrete or asphalt concrete base will be shown on the plans or specified in the special provisions.

Asphalt concrete and asphalt concrete base shall be produced in a batch mixing plant, a continuous pugmill mixing plant or a drier-drum mixing plant. Proportioning shall be either by hot-feed control or cold-feed control.

39-2 MATERIALS

39-2.01 ASPHALTS

Asphalt binder to be mixed with aggregate shall be a steam-refined paving asphalt conforming to the provisions in Section 92, "Asphalts," and shall be of the grade designated in the special provisions or as determined by the Engineer.

The amount of asphalt binder to be mixed with the aggregate for asphalt concrete (except Open Graded asphalt concrete) and asphalt concrete base will be determined by the Engineer in accordance with California Test 367 using the samples of aggregates furnished by the Contractor in conformance with Section 39-3.03, "Proportioning." The amount of asphalt binder to be mixed with the aggregate for Open Graded asphalt concrete will be determined by the Engineer in accordance with California Test 368, using the samples of aggregates furnished by the Contractor in conformance with Section 39-3.03.

Liquid asphalt for prime coat shall conform to the provisions in Section 93, "Liquid Asphalts," and shall be of the grade designated by the contract item or specified in the special provisions.

Asphaltic emulsion for paint binder (tack coat) shall conform to the provisions in Section 94, "Asphaltic Emulsions," for the rapid-setting or slow-setting type and grade selected by the Engineer.

Paving asphalt to be used as a binder for pavement reinforcing fabric shall be a steam-refined paving asphalt conforming to the provisions in Section 92, "Asphalts," and shall be Grade AR-4000, unless otherwise ordered by the Engineer.

39-2.02 AGGREGATE

All aggregates shall be clean and free from decomposed materials, organic material and other deleterious substances. Coarse aggregate is material retained on the 4.75-mm sieve; fine aggregate is material passing the 4.75-mm sieve; and supplemental fine aggregate is added fine material passing the 600-痠 sieve, including, but not limited to, cement and stored fines from dust collectors. Unless otherwise specified in the special provisions, the aggregate grading of the various types of asphalt concrete shall conform to the following:

Type	Grading
A	19-mm maximum, coarse
B	19-mm maximum, medium
Open Graded	9.5-mm maximum

The combined aggregate, prior to the addition of asphalt binder, shall conform to the requirements of this section. Conformance with the grading requirements will be determined by California Test 202, modified by California Test 105 when there is a difference in specific gravity of 0.2 or more between the coarse and fine portions of the aggregate or between blends of different aggregates.

In the tables below, the symbol "X" is the gradation which the Contractor proposes to furnish for the specific sieve. The proposed gradation shall meet the gradation shown in the table under "Limits of Proposed Gradation." Changes from one mix design to another shall not be made during the progress of the work unless permitted by the Engineer. However, changes in proportions to conform to the approved mix design shall not be considered changes in mix design.

AGGREGATE GRADING REQUIREMENTS
Types A and B Asphalt Concrete
Percentage Passing

19-mm Maximum, Coarse
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
25-mm	-	100	100
19-mm	-	90-100	87-100
9.5-mm	-	60-75	55-80
4.75-mm	45-50	X±5	X±8
2.36-mm	32-36	X±5	X±8
600-痠	15-18	X±5	X±8
75-痠	-	3-7	0-10

19-mm Maximum, Medium
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
25-mm	-	100	100
19-mm	-	95-100	90-100
9.5-mm	-	65-80	60-85
4.75-mm	49-54	X±5	X±8
2.36-mm	36-40	X±5	X±8
600-痠	18-21	X±5	X±8
75-痠	-	3-8	0-11

12.5-mm Maximum, Coarse
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
19-mm	-	100	100
12.5-mm	-	95-100	89-100
9.5-mm	-	75-90	70-95
4.75-mm	55-61	X±5	X±8
2.36-mm	40-45	X±5	X±8
600-痠	20-25	X±5	X±8
75-痠	-	3-7	0-10

12.5-mm Maximum, Medium
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
19-mm	-	100	100
12.5-mm	-	95-100	89-100
9.5-mm	-	80-95	75-100
4.75-mm	59-66	X±5	X±8
2.36-mm	43-49	X±5	X±8
600-痠	22-27	X±5	X±8
75-痠	-	3-8	0-11

9.5-mm Maximum
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
12.5-mm	-	100	100
9.5-mm	-	95-100	95-100
4.75-mm	73-77	X±6	X±10
2.36-mm	58-63	X±6	X±10
600-痠	29-34	X±6	X±10
75-痠	-	3-10	0-14

4.75-mm Maximum
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
9.5-mm	-	100	100
4.75-mm	-	95-100	95-100
2.36-mm	72-77	X±6	X±10
600-痠	37-43	X±7	X±11
75-痠	-	3-12	0-16

Open Graded Asphalt Concrete
Percentage Passing

12.5-mm Maximum
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
19-mm	-	100	100
12.5-mm	-	95-100	92-100
9.5-mm	78-89	X±4	X±7
4.75-mm	28-37	X±4	X±7
2.36-mm	7-18	X±4	X±5
1.18-mm	-	0-10	0-13
75-痠	-	0-3	0-4

9.5-mm Maximum
Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
12.5-mm	-	100	100
9.5-mm	-	90-100	88-100
4.75-mm	29-36	X±4	X±7
2.36-mm	7-18	X±4	X±5
1.18-mm	-	0-10	0-12
75-痠	-	0-3	0-4

Types A and B Asphalt Concrete Base
Percentage Passing

Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
31.5-mm	-	100	100
25-mm	-	95-100	92-100
19-mm	-	80-100	77-100
9.5-mm	55-60	X±5	X±8
4.75-mm	40-45	X±5	X±8
600-痠	14-19	X±5	X±8
75-痠	-	2-7	0-10

The combined aggregate shall conform to the following quality requirements prior to the addition of the asphalt:

Sieve Sizes	Limits of Proposed Gradation	Operating Range	Contract Compliance
31.5-mm	-	100	100
25-mm	-	95-100	92-100
19-mm	-	80-100	77-100
9.5-mm	55-60	X±5	X±8
4.75-mm	40-45	X±5	X±8
600-痠	14-19	X±5	X±8
75-痠	-	2-7	0-10

Tests	California Test	Asphalt Concrete Type		Open Graded Asphalt Concrete	Asphalt Concrete Base Type
		A	B		A	B
Percentage of crushed Particles	205
Coarse Aggregate (Min.)		90%	25%	90%	90%	25%
Fine Aggregate (Passing 4.75-mm, Retained on 2.36-mm) (Min.)		70%	20%	90%	70%	20%
Los Angeles Rattler	211
Loss at 100 Rev. (Max.)		10%		10%	10%
Loss at 500 Rev. (Max.)		45%	50%	40%	45%	50%
Sand Equivalent	217
Contract Compliance (Min.)		47	42	-	47	42
Operating Range (Min.)		50	45	-	50	45
Film Stripping (Max.)¹	302	-	-	25%	-	-
Kc Factor (Max.)	303	1.7	1.7	-	1.7	1.7
Kf Factor (Max.)	303	1.7	1.7	-	1.7	1.7
1 After mixing with asphalt binder

If the results of either or both the aggregate grading and Sand Equivalent tests do not meet the requirements specified for "Operating Range" but meet the "Contract Compliance" requirements, placement of the asphalt concrete or asphalt concrete base may be continued for the remainder of that day. However, another day's work may not be started until tests, or other information, indicate to the satisfaction of the Engineer that the next material to be used in the work will comply with the requirements specified for "Operating Range."

If the results of either or both the aggregate grading and Sand Equivalent tests do not meet the requirements specified for "Contract Compliance," the asphalt concrete or asphalt concrete base which is represented by these tests shall be removed. However, if requested by the Contractor and approved by the Engineer, the asphalt concrete or asphalt concrete base may remain in place and the Contractor shall pay to the State $1.95 per tonne for the asphalt concrete or asphalt concrete base represented by these tests and left in place. The Department may deduct this amount from any moneys due, or that may become due, the Contractor under the contract. If both the aggregate grading and Sand Equivalent do not conform to the "Contract Compliance" requirements, only one adjustment shall apply.

No single aggregate grading or Sand Equivalent test shall represent more than 450 tonnes or one day's production, whichever is smaller.

The asphalt concrete mixture, composed of the aggregate proposed for use and the optimum amount of asphalt as determined by California Test 367, shall conform to the following quality requirements:

Tests	California Test	Asphalt Concrete Type		Open Graded Asphalt Concrete	Asphalt Concrete Base Type
		A	B		A	B
Swell (Max.) (Millimeters)	305	0.76	0.76	-	0.76	0.76
Moisture Vapor Susceptibility (Min.)	307	30	25	-	30	25
Stabilometer Value (Min.)	366	37	35	-	37	35
Stabilometer Value (Min.) (9.5-mm or 4.75-mm Max. AC)	366	30	30	-	-	-

39-2.03 PAVEMENT REINFORCING FABRIC

Pavement reinforcing fabric shall conform to the provisions in Section 88, "Engineering Fabrics."

39-3 STORING, PROPORTIONING AND MIXING MATERIALS

39-3.01 STORAGE

Aggregate shall be stored so that separately sized aggregates will not be intermingled, and asphalt binder shall be stored so that different grades of asphalt will not be intermingled. Any aggregate which has been intermingled with another size of aggregate shall be removed and replaced with aggregate of specified grading. As used in this specification, "cold storage" is the storing of aggregates prior to their having been processed in a drier, and "hot storage" is the storing of aggregates after their having been processed in a drier. "Hot-feed control" and "cold-feed control" indicate the location of measuring devices or controls.

When the Contractor adds supplemental fine aggregate, each supplemental fine aggregate used shall be stored separately and kept thoroughly dry.

The measurement and storage requirements of this Section 39-3, shall not apply to the dust collected in skimmers and expansion chambers (knock-out boxes) or to the dust collected in centrifugal (cyclone) collectors. Dust from these collectors may be returned to the aggregate without being measured or stored separately, provided the dust is returned uniformly at a point in advance of the sampling device in batch-mixing plants or is returned at or before mixing in continuous mixing plants. Aggregate and asphalt binder shall also be stored in conformance with the following:

39-3.01A COLD STORAGE

When aggregate contains material of which at least 20 percent will pass the 2.36-mm sieve, the material shall be fed from storage by means of a mechanical feeder.

Before being fed to the drier, aggregate shall be separated into sizes and stored as follows:

39-3.01A(1) COLD STORAGE FOR PLANTS UTILIZING HOT-FEED CONTROL

Aggregate for asphalt concrete base shall be separated into 4 or more sizes and stored separately. Aggregate for Type A or Type B asphalt concrete of the 19-mm and 12.5-mm maximum sizes shall be separated into 3 or more sizes and stored separately.

Aggregate for Type A or Type B asphalt concrete of the 9.5-mm maximum size and the 4.75-mm maximum size, and aggregate for Open Graded asphalt concrete need not be separated into sizes and stored separately.

39-3.01A(2) COLD STORAGE FOR PLANTS UTILIZING COLD-FEED CONTROL

When the Contractor elects to use a plant equipped with cold-feed control, aggregate for asphalt concrete base shall be separated into 4 or more sizes. Aggregate for asphalt concrete of the 19-mm and 12.5-mm maximum sizes shall be separated into 3 or more sizes. Aggregate for asphalt concrete of the 9.5-mm maximum size and aggregate for Open Graded asphalt concrete shall be separated into 2 or more sizes. Aggregate for asphalt concrete of 4.75-mm maximum size need not be separated. After the aggregate is separated, each size shall be stored separately.

39-3.01B HOT STORAGE

Aggregate for asphalt concrete and asphalt concrete base to be mixed in batch mixing plants, after being dried, shall be stored in accordance with the following:

Aggregates for asphalt concrete base shall be separated into 4 or more sizes. Aggregates for asphalt concrete of 19-mm and 12.5-mm maximum sizes shall be separated into 3 or more sizes. Aggregate for asphalt concrete of 9.5-mm maximum size and aggregate for Open Graded asphalt concrete shall be separated into 2 or more sizes. Aggregate for asphalt concrete of 4.75-mm maximum size need not be separated.

After the aggregate is separated, each size shall be stored in a separate bin and shall be recombined in conformance with the provisions in Section 39-3.03, "Proportioning," to conform to the gradings specified in Section 39-2, "Materials."

Storage bins shall be provided with chutes to prevent overflow into adjacent bins.

39-3.01C ASPHALT BINDER STORAGE

Asphalt to be used as a binder for asphalt concrete shall be stored in tanks accurately calibrated in uniform intervals of 375- to 400-L intervals and maintained to this accuracy. They shall be made accessible for measuring the volume of asphalt at any time.

The Contractor shall provide a suitable sampling device in asphalt feed lines connecting plant storage tanks to the asphalt weighing system or spray bar. The sampling device shall consist of a valve with a nominal diameter between 10 and 20 mm constructed in a manner that a one-liter sample may be withdrawn slowly at any time during plant operations. The valve shall be maintained in good condition, and if it fails to function properly, it shall be replaced. The sampling device shall be readily accessible and in an area free of dangerous obstructions and shall be between 600 and 750 mm above the platform. A drainage receptacle shall be provided for flushing the device prior to sampling.

The discharge end of the asphalt binder circulating pipe shall be maintained below the surface of the asphalt binder in the storage tank to prevent discharging hot asphalt binder into open air.

A temperature-sensing device shall be installed in the asphalt feed line. The device shall measure the temperature of the asphalt and shall be accurate to 5蚓. The indicator shall be located and maintained at the point where the proportioning operations are controlled. When a recording type indicator is used, it shall be maintained in working condition and shall be serviced as required.

39-3.02 DRYING

Aggregate shall be fed directly to a drier-drum mixer or to a drier at a uniform rate.

Drying shall continue for a sufficient time and at a sufficiently high temperature that, at the time of spreading, the moisture content of the completed mixture shall not exceed one percent. Moisture content will be determined by California Test 310, 311, or 370.

The drier or drier-drum mixer shall be provided with a device which senses the temperature of the material leaving the drier or the drier-drum mixer. The temperature-sensing device shall be accurate to the nearest 5蚓, and shall be installed in such a manner that changes of 5蚓 in temperature of the material will be shown within one minute. The indicator shall be located and maintained at the point where the proportioning operations are controlled. When a recording type indicator is used, it shall be maintained in working condition and shall be serviced as required.

The burner used for heating the aggregate shall achieve complete combustion of the fuel.

39-3.03 PROPORTIONING

Before producing asphalt concrete or asphalt concrete base, the Contractor shall submit in writing to the Engineer the gradation of the aggregate for each mix which he proposes to furnish. If the aggregate is separated into 2 or more sizes, the proposed gradation shall consist of gradations for individual sizes, and the proposed proportions of individual sizes, combined mathematically to indicate one proposed gradation. The gradation shall meet the applicable grading requirements shown in Section 39-2.02, "Aggregate," and shall show the percentage passing each of the specified sieve sizes.

At least two weeks prior to their intended use, the Contractor shall furnish samples of aggregates, in the quantity requested by the Engineer, from the source the Contractor proposes to use for the project. The samples shall have been processed in a manner representative of that for the material to be used in the work. In batch-mixing plants, these samples shall be obtained from the normal sampling area, just before the weighhopper. In continuous mixing plants, the sample shall be obtained from the normal sampling area, after cold feed proportioning and in advance of the point where the aggregate enters the mixer. The bitumen ratio (kilograms of asphalt per 100 kg of dry aggregate including supplemental fine aggregate, if used) will be determined by the Engineer using California Test 367, or California Test 368 for Open Graded asphalt concrete.

Should the Contractor change the source of supply, the Contractor shall furnish new samples and proposed proportions, as determined by the Engineer to be necessary, at least two weeks before their intended use. A change which affects any portion of the total aggregate in the mix will be considered a change in source and will require a new mix design. Up to three mix designs will be performed by the State at State expense when the mix design is utilized for one or more working days. The Contractor shall bear all costs involved in developing any mix design not utilized for one or more days and for all mix designs developed after the first three that have been so utilized. The Engineer will determine the cost to the State for the mix designs and the Department may deduct this amount from any moneys due, or that may become due the Contractor under the contract.

Where asphalt concrete or asphalt concrete base is to be produced from established sources and if acceptable to the Engineer, the Contractor may advise the Engineer in writing that the source, gradings and proportions of those aggregates proposed to be furnished are the same as those approved for, and used on, another prior or concurrent project. The project shall be identified by contract number. The Engineer will determine if an existing mix design is acceptable for the current project.

39-3.03A PROPORTIONING FOR BATCH MIXING

When the Contractor elects to use batch mixing equipment, each aggregate storage bin shall be equipped with a suitable, safe sampling device which will provide a sample, representative of actual production, of the aggregate discharged into the weighhopper or volumetric proportioning bin. When the samples are taken from a location above ground level, a means shall be provided for lowering the aggregate samples to the ground.

The fine material collected in all dust control systems, other than centrifugal collectors or knock-out boxes, shall be proportioned as provided for supplemental fine aggregate in this Section 39-3.03A.

When supplemental fine aggregate is used, it shall be proportioned by mass as provided in Subsection a, "Mass Proportioning," of Section 39-3.03A(1), "Manual Proportioning." A suitable, safe sampling device shall be installed in each feed line or surge tank preceding the weighhopper. The delivery point of samples shall be safe and convenient.

Aggregate and asphalt shall be proportioned by mass or by volume as follows:
39-3.03A(1) MANUAL PROPORTIONING

An automatic plant shall not be operated manually unless the automatic circuitry is disconnected to the extent that it cannot be activated by the mere operation of a switch, circuit breaker, or some other similar routine procedure.

When manual proportioning is used in the production of asphalt concrete or asphalt concrete base, proportioning shall conform to the following:

Mass Proportioning - The zero tolerance for aggregate scales shall be 0.5-percent of the total batch mass of the aggregate. The zero tolerance for separate scales for weighing supplemental fine aggregate or asphalt binder shall be 0.05-percent of the total batch mass of the aggregate. The indicated mass of material drawn from storage for any draft of material shall not vary from the preselected scale setting by more than the following percentages of the total batch mass of the aggregate:

Aggregate shall be within one percent, except that when supplemental fine aggregate is used and is weighed cumulatively with the aggregate, the draft of aggregate drawn immediately before the supplemental fine aggregate shall be within 0.5-percent.
Supplemental fine aggregate shall be within 0.5-percent.
Asphalt binder shall be within 0.1-percent.
The asphalt binder shall be measured by a tank scale.

Volumetric Proportioning - Each size of aggregate, except supplemental fine aggregate, shall be proportioned in a separate bin that is adjustable in size. Each bin shall have a gate or other device so designed that the bin shall be completely filled and struck off in measuring the volume of aggregate to be used in the mix. Means shall be provided for calibrating the mass of material in each measuring bin at any time. The plant shall be operated in such a manner that the material in each aggregate bin is within 2 percent of the mass preselected for the type of mixture being produced.
Asphalt binder shall be proportioned by a meter or an adjustable calibrated tank. When meters are used, the asphalt lines leading to asphalt meters shall be full-circulating or shall be regulated so that, during plant stoppages, the temperature of the asphalt does not change more than 10蚓 from the temperature maintained while the plant is in full operation. Asphalt binder shall be proportioned to within 2 percent of the mass preselected for the mixture being produced.
39-3.03A(2) AUTOMATIC PROPORTIONING

When automatic batch mixing is required by the special provisions or when the Contractor elects to use an automatic batching system, the proportioning devices shall be automatic to the extent that the only manual operation required for proportioning all materials for one batch shall be a single operation of a switch or starter.

Mass Proportioning.- Automatic proportioning devices shall be of a type in which materials discharged from the several bins are controlled by gates or by mechanical conveyors. The batching devices shall be so interlocked that no new batch may be started until all weighhoppers are empty, the scales are at zero, and the discharge gates are closed. The means of withdrawal from the bins and of discharge from the weigh box shall be interlocked so that not more than one bin can discharge onto any given scale at one time, and that the weigh box cannot be tripped until the required quantity from each of the bins has been deposited therein. In addition, automatic proportioning devices shall be interlocked so that the weighing cycle will be interrupted whenever the amount of material drawn from any storage varies from the preselected amount by more than the tolerances specified in Section 39-3.03A(1), "Manual Proportioning." Whenever the weighing cycle is interrupted, that specific batch shall not be used in the work unless it can be manually adjusted to meet the specified tolerances based on the total mass of the batch. When partial batches are batched automatically, the interlock tolerances, except the zero tolerance, shall apply to the total mass of the aggregate in the partial batch.
Automatic proportioning devices shall be operated so that all mass increments required for a batch are preset on the controls at the same time. Controls shall be designed so that these settings may be changed without delay, and the order of discharge from the several bins can be changed as directed by the Engineer.
Automatic proportioning controls shall be equipped with means for inspection of the interlock tolerance settings, and instructions for doing so shall be immediately available at the point of operation. In order to check the accuracy of proportioning during plant operation, the Contractor shall provide means to check the mass of various proportioned amounts on a separate scale located at the plant.
Volumetric Proportioning.- Asphalt binder shall be proportioned by an adjustable calibrated tank. Automatic volumetric proportioning devices shall be of a type which will not allow the bins to discharge into the mixer unless the mixer is empty and the mixer discharge gate is closed and will not operate unless the aggregate bins and asphalt binder tank are full.
The automatic proportioning device shall operate in such a manner that the material in each aggregate bin and the asphalt binder tank is within 2 percent of the preselected mass.
In order to check the accuracy of proportioning during plant operation, the Contractor shall provide means to check the mass of various proportioned amounts on a separate scale located at the plant.

39-3.03B PROPORTIONING FOR CONTINUOUS MIXING

Asphalt binder shall be introduced into the mixer through a meter conforming to the requirements of Section 9-1.01, "Measurement of Quantities." The asphalt meter shall automatically compensate for changes in asphalt temperature, unless the meter is of the mass flow, coriolis effect, type. The system shall be capable of varying the rate of delivery of binder proportionate with the delivery of aggregate. During any day's run, the temperature of asphalt binder shall not vary more than 30蚓. The meter and lines shall be heated and insulated. The storage for binder shall be equipped with a device for automatic plant cut-off when the level of binder is lowered sufficiently to expose the pump suction line.

When supplemental fine aggregate is used, it shall be proportioned by mass by a method that uniformly feeds the material within 2 percent of the required amount. Supplemental fine aggregate shall be discharged from the proportioning device directly into the mixer.

The supplemental fine aggregate proportioning system shall function with such accuracy that, when operated at between 30 percent and 100 percent of maximum operating capacity, the average difference between the indicated mass of material delivered and the actual mass delivered will not exceed one percent of the actual mass for three 15-minute runs. For any of 3 individual 15-minute runs, the indicated mass of material delivered shall not vary from the actual mass delivered by more than 2 percent of the actual mass.

The fine material collected in all dust control systems may be returned to the aggregate production stream without proportioning if returned at a rate commensurate with overall plant production, and if returned at or before the mixer. Any return rate of less than 100 percent of the collection rate shall be metered as specified above for supplemental fine aggregate.

The asphalt feeder, each of the aggregate feeders, the supplemental fine aggregate feeder, if used, and the combined aggregate feeder, shall be equipped with devices by which the rate of feed can be determined while the plant is in full operation.

The combined aggregate shall be weighed using a belt scale. The belt scale shall be of such accuracy that, when the plant is operating between 30 percent and 100 percent of belt capacity, the average difference between the indicated mass of material delivered and the actual mass delivered will not exceed one percent of the actual mass for three 3-minute runs. For any of the 3 individual 3-minute runs, the indicated mass of material delivered shall not vary from the actual mass delivered by more than 2 percent of the actual mass.

The actual mass of material delivered for proportioning device calibrations shall be determined by a vehicle scale conforming to the requirements of Section 9-1.01, "Measurement of Quantities." The vehicle scale shall be located at the plant and shall be sealed within 24 hours of checking the plant's proportioning devices. The plant shall be equipped so that this accuracy check can be made prior to the first operation for a project and at any other time as directed by the Engineer.

The belt scale for the combined aggregate, the proportioning devices for supplemental fine aggregate, if used, and the asphalt proportioning meter shall be interlocked so that the rates of feed of the aggregates and asphalt will be adjusted automatically (at all production rates and production rate changes) to maintain the bitumen ratio (kilograms of asphalt per 100 kg of dry aggregate including supplemental fine aggregate, if used) designated by the Engineer. The plant shall not be operated unless this automatic system is operating and in good working condition.

Asphalt meters and aggregate belt scales used for proportioning aggregates and asphalt shall be equipped with rate-of-flow indicators to show the rates of delivery of asphalt and aggregate, and resettable totalizers so that the total amounts of asphalt and aggregate introduced into the mixture can be determined. Rate-of-flow indicators and totalizers for like materials shall be accurate within one percent when compared directly. The asphalt cement totalizer shall not register when the asphalt metering system is not delivering material to the mixer.

The bin or bins containing the fine aggregate and supplemental fine aggregate, if used, shall be equipped with vibrating units or other equipment which will prevent any hang-up of material while the plant is operating. Each belt feeder shall be equipped with a device to monitor the depth of aggregate between the troughing rollers. The device for monitoring depth of aggregate shall automatically shut down the plant whenever the depth of aggregate is less than 70 percent of the target depth. To avoid erroneous shutdown by normal fluctuation, a delay between sensing less than 70 percent flow and shutdown of the plant will be permitted, as determined by the Engineer, at the time of the initial California Test 109. A second device shall be located either in the stream of aggregate beyond the belt or where it will monitor movement of the belt by detecting revolutions of the tail pulley on the belt feeder. The device for monitoring no flow or belt movement, as the case may be, shall stop the plant automatically and immediately when there is no flow. The plant shall not be operated unless both low-flow and no-flow devices are in good working condition and functioning.

The Contractor shall determine the moisture content of the aggregate at least once during each 2 hours of production and shall adjust the moisture control equipment accordingly.

For continuous pugmill mixing plants an aggregate sampling device which will provide a 25- to 40-kg sample of the combined aggregate while the plant is in full operation shall be provided in advance of the point where the aggregate enters the mixer.

For drier-drum mixing plants an aggregate sampling device which will provide a 25- to 40-kg sample of the combined aggregate while the plant is in full operation shall be provided in advance of the point where the aggregate enters the drier-drum mixer.

When the samples are taken from a location above ground level, a means shall be provided for lowering the aggregate samples to the ground.

When supplemental fine aggregate is used, a suitable, safe sampling device shall be installed in each feed line or surge tank preceding the proportioning device for the supplemental fine aggregate.

39-3.04 MIXING

Aggregate, supplemental fine aggregate, and asphalt binder shall be mixed in a batch mixer, continuous mixing pugmill mixer, or continuous mixing drier-drum mixer. The asphalt content of the asphalt mixture will be determined by extraction tests in accordance with California Test 310 or 362, or will be determined in accordance with California Test 379. The bitumen ratio (kilograms of asphalt per 100 kg of dry aggregate including supplemental fine aggregate if used) shall not vary by more than 0.5-kg of asphalt above or 0.5-kg of asphalt below the amount designated by the Engineer. Compliance with this requirement, except for Open Graded asphalt concrete, will be determined by testing samples taken from the mat behind the paver before initial or breakdown compaction of the mat.

For Open Graded asphalt concrete, compliance with this requirement will be determined either by taking samples from trucks at the plant or from the mat behind the paver before initial or breakdown compaction of the mat. If the sample of Open Graded asphalt concrete is taken from the mat behind the paver, the bitumen ratio shall be not less than the amount designated by the Engineer, less 0.7-kg of asphalt per 100 kg of dry aggregate, nor more than the amount designated by the Engineer, plus 0.5-kg of asphalt per 100 kg of dry aggregate.

The charge in a batch mixer, or the rate of feed to a continuous mixer, shall not exceed that which will permit complete mixing of all of the material. Dead areas in the mixer, in which the material does not move or is not sufficiently agitated, shall be corrected by a reduction in the volume of material or by other adjustments.

Asphalt binder shall be at a temperature of not less than 120蚓 nor more than 190蚓 when added to the aggregate.

The temperature of the aggregate before adding the binder, except for Open Graded mixes, shall be not more than 165蚓. The temperature of the aggregate for Open Graded mixtures shall be not more than 135蚓.

39-3.04A BATCH MIXING

When asphalt concrete or asphalt concrete base is produced by batch mixing, the mixer shall be equipped with a sufficient number of paddles of a type and arrangement to produce a properly mixed batch. The binder shall be introduced uniformly into the mixer along the center of the mixer parallel to the mixer shafts, or by pressure spraying. When a pan is used, it shall be equipped with movable vanes in order that the flow of binder may be directed across the width of the pan, as desired. The vanes shall be equipped with a means for quick adjustment, and a positive lock to prevent shifting.

The mixer platform shall be of ample size to provide safe and convenient access to the mixer and other equipment. The mixer housing and weighbox housing shall be provided with gates of ample size to permit ready sampling of the discharge of aggregate from each of the plant bins and from each feed line or surge tank of supplemental fine aggregate, if used. The Contractor shall provide a sampling device capable of delivering a representative sample of sufficient size to permit the required tests. The mixer shall be equipped with a timing device which will indicate by a definite audible or visual signal the expiration of the mixing period. The device shall measure the time of mixing within 2 seconds.

The time of mixing a batch shall begin on the charging stroke of the weighhopper dumping mechanism and shall end when discharge is started. Mixing shall continue until a homogeneous mixture of uniformly distributed and properly coated aggregates of unchanging appearance is produced. The time of mixing shall be not less than 30 seconds.

When automatic proportioning or automatic batch mixing is required by the special provisions or when the Contractor elects to use an automatic batching system, an interval timer shall control the time of mixing. The interval timer shall be interlocked so that the mixer cannot be discharged until all of the materials have been mixed for the full time specified.

39-3.04B CONTINUOUS MIXING

Continuous mixing plants shall utilize pugmill or drier-drum mixers.

When asphalt concrete or asphalt concrete base is produced by pugmill mixing, the mixer shall be equipped with paddles of a type and arrangement to provide sufficient mixing action and movement to the mixture to produce properly mixed asphalt concrete or asphalt concrete base. The combined aggregate shall be fed directly from the drier to the mixer at a uniform and controlled rate.

Mixing shall continue until a homogeneous mixture of thoroughly and uniformly coated aggregates of unchanging appearance is produced at discharge from the mixer.

Temperature of the completed mixture shall not exceed 165蚓 at discharge from the mixer.

The mixer shall discharge into a storage silo with a capacity of not less than that specified in Section 39-3.05, "Asphalt Concrete and Asphalt Concrete Base Storage." The Contractor shall provide a means of diverting the flow of asphalt concrete or asphalt concrete base away from the silo to prevent incompletely mixed portions of the mixture from entering the silo.

39-3.05 ASPHALT CONCRETE AND ASPHALT CONCRETE BASE STORAGE

When asphalt concrete or asphalt concrete base is stored, it shall be stored only in silos. Asphalt concrete or asphalt concrete base shall not be stockpiled. The minimum quantity of asphalt concrete or asphalt concrete base in any one silo during mixing shall be 18 tonnes except for the period immediately following a shutdown of the plant of 2 hours or more. A means shall be provided to indicate that storage in each silo is being maintained as required.

Storage silos shall be equipped with a surge-batcher sized to hold a minimum of 1800 kg of material. A surge-batcher consists of equipment placed at the top of the storage silo which catches the continuous delivery of the completed mix and changes it to individual batch delivery and prevents the segregation of product ingredients as the completed mix is placed into storage. The surge-batcher shall be center loading and shall be thermally insulated or heated or thermally insulated and heated to prevent material buildup. Rotary chutes shall not be used as surge-batchers.

The surge-batcher shall be independent and distinct from conveyors or chutes used to collect or direct the completed mixture being discharged into storage silos and shall be the last device to handle the material before it enters the silo. Multiple storage silos shall be served by an individual surge-batcher for each silo. Material handling shall be free of oblique movement between the highest elevation (conveyor outfall) and subsequent placement in the silo. Discharge gates on surge-batchers shall be automatic in operation and shall discharge only after a minimum of 1800 kg of material has been collected and shall close before the last collected material leaves the device. Discharge gate design shall prevent the deflection of material during the opening and closing operation.

Open Graded asphalt concrete stored in excess of 2 hours, and any other asphalt concrete or asphalt concrete base stored in excess of 18 hours, shall not be used in the work.

Asphalt concrete or asphalt concrete base with hardened lumps in the mixture shall not be used. Any storage facility which contained the material with the hardened lumps shall not be used for further storage until the cause of the lumps is corrected.

39-3.06 ASPHALT CONCRETE PLANTS

Any plants, including commercial plants, that produce asphalt concrete or asphalt concrete base that is subject to these specifications shall conform to the provisions in Section 7-1.01F, "Air Pollution Control," and shall be equipped with a wet-tube dust washer or equal and other devices which will reduce the dust emission to the degree that adjacent property is not damaged. The washer and other equipment shall function efficiently at all times when the plant is in operation.

During production, petroleum products such as diesel fuel and kerosene shall not be used as a release agent on belts, conveyors, hoppers or hauling equipment.

Plants shall be equipped with an inspection dock so constructed that an inspector standing on the dock can inspect the completed mix and take samples, as necessary, from the hauling vehicle before the vehicle leaves the plant site. This inspection dock shall allow the vehicle to pull alongside and shall meet all applicable safety requirements of the California Division Of Occupational Safety and Health. Drivers shall be instructed to stop at the dock whenever an inspector is on the dock and to remain there until directed to leave by the inspector.

39-4. SUBGRADE, PRIME COAT, PAINT BINDER (TACK COAT), AND PAVEMENT REINFORCING FABRIC

39-4.01 SUBGRADE

Immediately prior to applying prime coat or paint binder (tack coat), or immediately prior to placing the asphalt concrete or asphalt concrete base when a prime coat or paint binder (tack coat) is not required, the subgrade to receive asphalt concrete or asphalt concrete base shall conform to the compaction requirement and elevation tolerances specified for the material involved and shall be free of loose or extraneous material. If the asphalt concrete or asphalt concrete base is to be placed on an existing base or pavement which was not constructed as part of the contract, the Contractor shall clean the surface by sweeping, flushing or other means to remove all loose particles of paving, all dirt and all other extraneous material immediately before applying the prime coat or paint binder (tack coat).

39-4.02 PRIME COAT AND PAINT BINDER (TACK COAT)

A prime coat of liquid asphalt shall be applied to the areas to be surfaced when there is a contract item for the work or when the work is required by the special provisions.

Prime coat shall be applied only to those areas designated by the Engineer.

Prime coat shall be applied at the approximate total rate of 1.15 L per square meter of surface covered. The exact rate and number of applications will be determined by the Engineer. Prime coat shall be applied at a temperature conforming to the range of temperatures provided in Section 93-1.03, "Mixing and Applying," for distributor application of the grade of liquid asphalt being used.v A paint binder (tack coat) of asphaltic emulsion shall be furnished and applied in accordance with the provisions in Section 94, "Asphaltic Emulsions," and shall be applied to all vertical surfaces of existing pavement, curbs, gutters, and construction joints in the surfacing against which additional material is to be placed, to a pavement to be surfaced, and to other surfaces designated in the special provisions.

Paint binder (tack coat) shall be applied in one application at a rate of from 0.10- to 0.45-L per square meter surface covered. The exact rate of application will be determined by the Engineer. Before placing a layer of Open Graded asphalt concrete on any other type of asphalt concrete or on an existing bituminous pavement, paint binder (tack coat) shall be applied in one application at a rate of from 0.25- to 0.45-L per square meter of surface covered. The exact rate of application will be determined by the Engineer.

At the Contractor's option, paving asphalt may be used for paint binder (tack coat) instead of asphaltic emulsion. If paving asphalt is used, the grade to be used and the rate of application will be determined by the Engineer. The paving asphalt shall be applied at a temperature of not less than 140蚓 nor more than 175蚓.

Prime coat or paint binder (tack coat) shall be applied only so far in advance of placing the surfacing as may be permitted by the Engineer. When asphaltic emulsion is used as a paint binder (tack coat), asphalt concrete shall not be placed until the asphaltic emulsion has cured.

Immediately in advance of placing asphalt concrete or asphalt concrete base, additional prime coat or paint binder (tack coat) shall be applied as directed by the Engineer to areas where the prime coat or paint binder (tack coat) has been damaged, and loose or extraneous material shall be removed, and no additional compensation will be allowed therefore.

39-4.03 PAVEMENT REINFORCING FABRIC

Pavement reinforcing fabric shall be placed on existing pavement to be surfaced or between layers of asphalt concrete when the work is shown on the plans, or specified in the special provisions, or ordered by the Engineer.

Before placing the pavement reinforcing fabric, a binder of paving asphalt shall be applied to the surface to receive the pavement reinforcing fabric at an approximate rate of 1.15 L per square meter of surface covered. The exact rate will be determined by the Engineer. The binder shall be applied to a width equal to the width of the fabric mat plus 75 mm on each side.

Before applying binder, large cracks, spalls and chuckholes in existing pavement shall be repaired as directed by the Engineer, and the repair work will be paid for as extra work as provided in Section 4-1.03D.

The fabric shall be aligned and placed with no wrinkles that lap. The test for lapping shall be made by gathering together the fabric in a wrinkle. If the height of the doubled portion of extra fabric is 15 mm or more, the fabric shall be cut to remove the wrinkle, then lapped in the direction of paving. Lap in excess of 50 mm shall be removed.

Pavement reinforcing fabric shall not be placed in areas of conform tapers where the thickness of the overlying asphalt concrete is 30 mm or less.

If manual laydown methods are used, the fabric shall be unrolled, aligned, and placed in increments of approximately 9 m.

Adjacent borders of the fabric shall be lapped 50 to 100 mm. The preceding roll shall lap 50 to 100 mm over the following roll in the direction of paving at ends of rolls or at any break. At fabric overlays, both the binder and the fabric shall overlap the previously placed fabric by the same amount. Seating of the fabric with rolling equipment after placing will be permitted. Turning of the paving machine and other vehicles shall be gradual and kept to a minimum to avoid damage.

A small quantity of asphalt concrete, to be determined by the Engineer, may be spread over the fabric immediately in advance of placing asphalt concrete surfacing in order to prevent fabric from being picked up by construction equipment.

Public traffic shall not be allowed on the bare reinforcing fabric, except that public cross traffic shall be allowed to cross the fabric, under traffic control, after the Contractor has placed a small quantity of asphalt concrete over the fabric.

Care shall be taken to avoid tracking binder material onto the pavement reinforcing fabric or distorting the fabric during seating of the fabric with rolling equipment. If necessary, exposed binder material shall be covered lightly with sand.

39-5 SPREADING AND COMPACTING EQUIPMENT

39-5.01 SPREADING EQUIPMENT

Asphalt pavers shall be self-propelled mechanical spreading and finishing equipment, provided with a screed or strike-off assembly capable of distributing the material to not less than the full width of a traffic lane. Screed action shall include any cutting, crowding or other practical action which is effective on the mixture without tearing, shoving or gouging, and which produces a surface texture of uniform appearance. The screed shall be adjustable to the required section and thickness. The paver shall be provided with a suitable full width compacting device. Pavers that leave ridges, indentations or other marks in the surface shall not be used unless the ridges, indentations or other marks are eliminated by rolling or prevented by adjustment in operation.

The asphalt paver shall operate independently of the vehicle being unloaded or shall be capable of propelling the vehicle being unloaded in a satisfactory manner. The load of the haul vehicle shall be limited to that which will ensure satisfactory spreading. While being unloaded the haul vehicle shall be in contact with the machine at all times, and the brakes on the haul vehicle shall not be depended upon to maintain contact between the vehicle and the machine.

No portion of the mass of hauling or loading equipment, other than the connection, shall be supported by the asphalt paver, and no vibrations or other motions of the loader, which could have a detrimental effect on the riding quality of the completed pavement, shall be transmitted to the paver.

When asphalt concrete is placed directly upon asphalt treated permeable base, the asphalt concrete shall be placed with a paver equipped with tracks unless the layer being placed is 45 mm or less in compacted thickness.

39-5.02 COMPACTING EQUIPMENT

A minimum of one steel-tired, 2-axle tandem roller weighing not less than 7.2 tonnes nor more than 9.1 tonnes shall be used for each asphalt paver to compact Open Graded asphalt concrete, and a minimum of 3 rollers consisting of the following shall be used for each asphalt paver to compact all other asphalt concrete and asphalt concrete base:

One steel-tired roller weighing not less than 7.2 tonnes;
One steel-tired, 2-axle or 3-axle tandem or 3-wheel roller weighing not less than 11 tonnes; and
One pneumatic-tired roller.

The 2-axle or 3-axle tandem or 3-wheel roller shall have rolling wheels with a diameter of one meter or more.

Except when leveling or when asphalt concrete less than 60 mm in compacted thickness is being placed on existing surfacing, pneumatic-tired rollers will not be required when approved vibratory rollers are furnished and used as specified in Section 39-6.03, "Compacting."

Each roller shall have a separate operator. All rolling equipment shall be self-propelled and reversible. The minimum number, mass, and type of rollers required may be reduced or modified in accordance with the provisions of Section 39-6.03, "Compacting," for low rates of production or when alternative equipment is approved by the Engineer.

All rollers shall be equipped with pads and water systems which prevent sticking of asphalt mixtures to the pneumatic- or steel-tired wheels. A parting agent, which will not damage the asphalt mixture, as determined by the Engineer, may be used to aid in preventing the sticking of the mixture to the wheels. Other equipment, approved by the Engineer in accordance with California Test 113, may be substituted for 3-wheel or tandem rollers when used as specified in Section 39-6.03, "Compacting."

Pneumatic-tired rollers shall be the oscillating type having a width of not less than 1.2 m with pneumatic tires of equal size, diameter and having treads satisfactory to the Engineer. Wobble-wheel rollers will not be permitted. The tires shall be spaced so that the gaps between adjacent tires will be covered by the following tires.

The tires shall be inflated to 620 kPa, or a lower pressure as designated by the Engineer, and maintained so that the air pressure will not vary more than 35 kPa from the designated pressure. Pneumatic-tired rollers shall be constructed so that the total mass of the roller can be varied to produce an operating mass per tire of not less than 900 kg. The total operating mass of the roller shall be varied as directed by the Engineer.

39-6 SPREADING AND COMPACTING

39-6.01 GENERAL REQUIREMENTS

Placing material in a windrow, then picking it up and placing it in the asphalt paver with loading equipment, will be permitted provided:

The asphalt paver is of such design that the material will fall into a hopper which has a movable bottom conveyor to feed the screed.
The loader (pick-up machine) is constructed and operated so that substantially all of the material deposited on the roadbed is picked up and deposited in the paving machine.
The windrow is deposited only so far in advance of the paver to provide for continuous operation of the paver and not so far as to allow the temperature of the asphalt concrete in the windrow to fall below 125蚓.

Unless lower temperatures are directed by the Engineer, all mixtures, except Open Graded asphalt concrete, shall be spread, and the first coverage of initial or breakdown compaction shall be performed when the temperature of the mixture is not less than 120蚓, and all breakdown compaction shall be completed before the temperature of the mixture drops below 95蚓. Open Graded asphalt concrete shall be spread at a temperature of not less than 95蚓, and not more than 120蚓, measured in the hopper of the paving machine. Open Graded asphalt concrete shall be compacted as soon as possible after spreading.

Type A and Type B asphalt concrete shall be placed only when the atmospheric temperature is above 10蚓. Asphalt concrete base shall be placed only when the atmospheric temperature is above 5蚓. Open Graded asphalt concrete shall be placed only when the atmospheric temperature is above 20蚓 and, where placement is to be on bridges or other structures, when the surface temperature of the structure is above 15蚓.

Asphalt concrete and asphalt concrete base shall not be placed when the underlying layer or surface is frozen, or when, in the opinion of the Engineer, weather conditions will prevent the proper handling, finishing, or compaction of the mixtures. Asphalt concrete shall be spread and compacted in the number of layers of the thicknesses indicated in the following table:

Total Thickness Shown on the Plans*	No. Layers	Top Layer Thickness (Millimeters)		Next Lower Layer Thickness (Millimeters)		All Other Lower Layers Thickness (Millimeters)
		Min.	Max.	Min.	Max.	Min.	Max.
60 mm or less	one	-	-	-	-	-	-
75 mm	2**	35	40	35	40	-	-
90 through 120 mm	2	45	60	45	75	-	-
135 mm or more	***	45	60	45	75	45	120
When pavement reinforcing fabric is shown to be placed between layers of asphalt concrete, the thickness of asphalt concrete above the pavement reinforcing fabric shall be considered to be the "Total Thickness Shown on the Plans" for the purpose of spreading and compacting the asphalt concrete above the pavement reinforcing fabric. * At the option of the Contractor, may be placed in one layer 75 mm thick. *** At least 2 layers if total thickness is 135 mm. At least 3 layers if total thickness is more than 135 mm and less than 270 mm. At least 4 layers if total thickness is 270 mm or more.

Asphalt concrete base shall be spread and compacted in one or more layers. Each layer of asphalt concrete base shall be not less than 60 mm nor more than 120 mm in compacted thickness, except that where the total thickness of asphalt concrete to be placed over asphalt concrete base is 60 mm or less, the layer of asphalt concrete base below the asphalt concrete shall not exceed 75 mm.

A layer shall not be placed over a layer which exceeds 75 mm in compacted thickness until the temperature of the layer which exceeds 75 mm in compacted thickness is less than 70蚓 at mid depth. Asphalt concrete and asphalt concrete base to be placed on shoulders, and other areas off the traveled way having a width of 1.50 m or more, shall be spread in the same manner as specified above. When the shoulders and other areas are less than 1.50 m in width, the material may be deposited and spread in one or more layers by any mechanical means that will produce a uniform smoothness and texture. Unless otherwise shown on the plans, asphalt mixtures shall not be handled, spread or windrowed in a manner that will stain the finished surface of any pavement or other improvements.

The completed mixture shall be deposited on the roadbed at a uniform quantity per linear meter, as necessary to provide the required compacted thickness without resorting to spotting, picking-up or otherwise shifting the mixture.

Segregation shall be avoided, and the surfacing shall be free from pockets of coarse or fine material. Asphalt concrete or asphalt concrete base containing hardened lumps shall not be used.

Longitudinal joints in the top layer shall correspond with the edges of proposed traffic lanes. Longitudinal joints in all other layers shall be offset not less than 150 mm alternately each side of the edges of traffic lanes. The Engineer may permit other patterns of placing longitudinal joints if he considers that those patterns will not adversely affect the quality of the finished product.

Unless otherwise provided herein or permitted by the Engineer, the top layer of asphalt concrete for shoulders, tapers, transitions, road connections, private drives, curve widenings, chain control lanes, turnouts, left turn pockets, and other such areas, shall not be spread before the top layer of asphalt concrete for the adjoining through lane has been spread and compacted. At locations where the number of lanes is changed, the top layer for the through lanes shall be paved first. When existing pavement is to be surfaced and the specified thickness of asphalt concrete to be spread and compacted on the existing pavement is 75 mm or less, shoulders or other adjoining areas may be spread simultaneously with the through lane provided the completed surfacing conforms to the requirements of these specifications. Tracks or wheels of spreading equipment shall not be operated on the top layer of asphalt concrete in any area until final compaction has been completed.

At locations shown on the plans, specified in the special provisions or as directed by the Engineer, the asphalt concrete shall be tapered or feathered to conform to existing surfacing or to other highway and non-highway facilities.

At locations where the asphalt concrete or asphalt concrete base is to be placed over areas inaccessible to spreading and rolling equipment, the asphalt concrete or asphalt concrete base shall be spread by any means to obtain the specified results and shall be compacted thoroughly to the required lines, grades and cross sections by means of pneumatic tampers, or by other methods that will produce the same degree of compaction as pneumatic tampers.

39-6.02 SPREADING

All layers, except as otherwise provided in Section 39-6.01, "General Requirements," and in this Section 39-6.02, shall be spread with an asphalt paver. Asphalt pavers shall be operated in such a manner as to ensure continuous and uniform movement of the paver.

In advance of spreading asphalt concrete over an existing base, surfacing, or bridge deck, if there is a contract item for asphalt concrete (leveling) or if ordered by the Engineer, asphalt concrete shall be spread by any mechanical means that will produce a uniform smoothness and texture to level irregularities, and to provide a smooth base in order that subsequent layers will be of uniform thickness.

When directed by the Engineer, paint binder (tack coat) shall be applied to any layer in advance of spreading the next layer.

Before placing the top layer adjacent to cold transverse construction joints, the joints shall be trimmed to a vertical face and to a neat line. Transverse joints shall be tested with a 3.6-m�0.06-m straightedge and shall be cut back as required to conform to the requirements specified in Section 39-6.03, "Compacting," for surface smoothness. Connections to existing surfacing shall be feathered to conform to the requirements for smoothness. Longitudinal joints shall be trimmed to a vertical face and to a neat line if the edges of the previously laid surfacing are, in the opinion of the Engineer, in such condition that the quality of the completed joint will be affected.

39-6.03 COMPACTING

Compacting equipment shall conform to the provisions of Section 39-5.02, "Compacting Equipment." A pass shall be one movement of a roller in either direction. A coverage shall be as many passes as are necessary to cover the entire width being paved. Overlap between passes during any coverage, made to ensure compaction without displacement of material in accordance with good rolling practice, shall be considered to be part of the coverage being made and not part of a subsequent coverage. Each coverage shall be completed before subsequent coverages are started.

Rolling shall commence at the lower edge and shall progress toward the highest portion, except that when compacting layers which exceed 75 mm in compacted thickness, and if directed by the Engineer, rolling shall commence at the center and shall progress outwards.

Compaction of Open Graded asphalt concrete shall consist of 2 coverages. If necessary, only one coverage of the Open Graded asphalt concrete may be ordered by the Engineer to prevent a break in the bond of asphalt between the aggregate particles.

All other asphalt concrete and asphalt concrete base shall be compacted as follows:

Initial or breakdown compaction shall consist of 3 coverages of a layer of asphalt mixture and shall be performed with a 2-axle or 3-axle tandem or a 3-wheel roller weighing not less than 11 tonnes. Where the thickness of the layer of asphalt mixture is less than 45 mm, fewer coverages than specified above may be ordered by the Engineer if necessary to prevent damage to the layer being compacted. The initial or breakdown compaction shall be followed immediately by additional rolling consisting of 3 coverages with a pneumatic-tired roller. Coverages with a pneumatic-tired roller shall start when the temperature of the mixture is as high as practicable, preferably above 80蚓, and shall be completed while the temperature of the mixture is at or above 65蚓. Each layer of asphalt concrete and asphalt concrete base shall be compacted additionally without delay by a final rolling consisting of not less than one coverage with a steel-tired roller weighing not less than 7.2 tonnes. Except as otherwise provided for low rates of production, a separate finish roller will be required.

Rolling shall be performed so that cracking, shoving or displacement will be avoided. Rolling, where 3-axle tandem rollers may be used as specified in this Section 39-6.03, shall be under the control of the Engineer, but in general, no 3-axle tandem roller shall be used in rolling over a crown or on warped sections when the center axle is in the locked position.

Provided it is demonstrated to the satisfaction of the Engineer that one roller can perform the work, the required minimum rolling equipment specified above may be reduced to one 2-axle tandem roller, weighing at least 7.2 tonnes, for each paver under any of the following conditions:

When asphalt concrete or asphalt concrete base is placed at a rate of 45 tonnes, or less, per hour at any location.
When asphalt concrete or asphalt concrete base is placed at a rate of 90 tonnes, or less, per hour and at the locations or under the conditions as follows:
1. Placed on miscellaneous areas in accordance with the provisions in Section 39-7.01, "Miscellaneous Areas."
2. When the width to be placed is less than 2.4 m.
When the total amount of asphalt concrete and asphalt concrete base included in the contract is 900 tonnes, or less.

When rolling equipment is reduced as provided in this Section 39-6.03, the rolling requirements may be reduced to at least 3 complete coverages with the tandem roller.

Alternative compacting equipment, approved by the Engineer in accordance with California Test 113, may be used for the initial or breakdown compaction if operated according to the procedures and under the conditions designated in the approval. Except when leveling or when asphalt concrete less than 60 mm in compacted thickness is being placed on existing surfacing, additional compaction with pneumatic-tired rollers will not be required when approved alternative equipment has been used for the initial compaction. A vibratory roller may be used as the finish roller provided that it meets the requirements for a finish roller and is operated with the vibratory unit turned off.

Upon completion of rolling operations, if ordered by the Engineer, the asphalt concrete or asphalt concrete base shall be cooled by applying water. Applying water shall conform to the provisions in Section 17, "Watering."

The completed surfacing shall be thoroughly compacted, smooth, and free from ruts, humps, depressions, or irregularities. Any ridges, indentations or other objectionable marks left in the surface of the asphalt concrete by blading or other equipment shall be eliminated by rolling or other means. The use of any equipment that leaves ridges, indentations, or other objectionable marks in the asphalt concrete shall be discontinued, and acceptable equipment shall be furnished by the Contractor.

When a straightedge 3.6 m±0.06-m long is laid on the finished surface and parallel with the center line, the surface shall not vary more than 3 mm from the lower edge of the straightedge. The transverse slope of the finished surface shall be uniform to a degree such that no depressions greater than 6 mm are present when tested with a straightedge 3.6 m±0.06-m long laid in a direction transverse to the center line and extending from edge to edge of a 3.6-m traffic lane.

Pavement within 15 m of a structure or approach slab shall conform to the smoothness tolerances specified in Section 51-1.17, "Finishing Bridge Decks."

39-7 MISCELLANEOUS

39-7.01 MISCELLANOUS AREAS

Surfacing of miscellaneous areas, such as median areas (exclusive of inside shoulders), island areas, sidewalks, dikes, gutters, gutter flares, ditches, overside drains, aprons at the ends of drainage structures, and other areas outside the traveled way which are designated on the plans as miscellaneous areas to be paved with asphalt concrete, shall conform to these specifications.

The combined aggregate grading for asphalt concrete placed on miscellaneous areas shall conform to that specified for the asphalt concrete placed on the traveled way, unless otherwise directed by the Engineer. The amount of asphalt binder used in the asphalt concrete placed in dikes, gutters, gutter flares, overside drains and aprons at the ends of drainage structures, unless otherwise directed by the Engineer, shall be increased one percent by mass of the aggregate over the amount of asphalt binder used in the asphalt concrete placed on the traveled way.

The asphalt concrete placed in miscellaneous areas may be spread in one layer. The material shall be compacted to the required lines, grades and cross section.

Dikes shall be shaped and compacted with an extrusion machine or other equipment capable of shaping and compacting the material to the required cross section.

39-7.02 SEAL COAT

Where shown on the plans or provided in the special provisions, a fog seal coat shall be applied to the surface of Types A and B asphalt concrete in accordance with the provisions in Section 37, "Bituminous Seals."

39-8 MEASUREMENT AND PAYMENT

39-8.01 MEASUREMENT

Asphalt concrete and asphalt concrete base will be measured by mass. The quantity to be paid for will be the combined mass of the mixture for the various types of asphalt concrete or asphalt concrete base, whichever is designated in the Engineer's Estimate.

The mass of the materials will be determined as provided in Section 9-1.01, "Measurement of Quantities."

Quantities of paving asphalt, liquid asphalt and asphaltic emulsion to be paid for as contract items of work will be determined in accordance with the methods provided in Sections 92, "Asphalts," 93, "Liquid Asphalts," or 94, "Asphaltic Emulsions," as the case may be.

When recorded batch masses are printed automatically, these masses may be used for determining pay quantities providing the following requirements are complied with:

Total aggregate and supplemental fine aggregate mass per batch shall be printed. When supplemental fine aggregate is weighed cumulatively with the aggregate, the total batch mass of aggregate shall include the supplemental fine aggregate.
Total bitumen mass per batch shall be printed.
Zero-tolerance mass shall be printed prior to weighing the first batch and after weighing the last batch of each truckload.
Time, date, mix number, load number and truck identification shall be correlated with load slip.
A copy of the recorded batch masses shall be certified by a licensed weighmaster and submitted to the Engineer.

When there is a contract item to place asphalt concrete dikes by the meter, the quantity to be paid for will be the length in meters measured along the completed dike. When there is a contract item to place asphalt concrete (miscellaneous area), the quantity to be paid for will be the area in square meters of the asphalt concrete compacted in place. In addition to the quantities for placing asphalt concrete measured on a meter or square meter basis, the asphalt concrete to be placed will also be measured for payment.

Pavement reinforcing fabric will be measured and paid for by the square meter for the actual pavement area covered.

39-8.02 PAYMENT

Asphalt concrete placed in the work, unless otherwise specified, will be paid for at the contract price per tonne for asphalt concrete or asphalt concrete base of the types designated in the Engineer's Estimate.

When there is a contract item for asphalt concrete (leveling), quantities of asphalt concrete placed for leveling will be paid for at the contract price per tonne for asphalt concrete (leveling). When there is no contract item for asphalt concrete (leveling), and leveling is ordered by the Engineer, asphalt concrete so used will be paid for as extra work as provided in Section 4-1.03D.

When there is a contract item for place asphalt concrete dike by the meter, quantities of dikes will be paid for at the contract price per tonne for asphalt concrete and also at the contract price per meter for place asphalt concrete dike. Full compensation for any necessary excavation, backfill and preparation of the area shall be considered as included in the contract price paid per meter for place asphalt concrete dike and no additional compensation will be allowed therefor.

Quantities of asphalt concrete placed in miscellaneous areas designated in the special provisions or tabulated on the plans to be included in the contract item of place asphalt concrete (miscellaneous area), will be paid for at the contract price per tonne for asphalt concrete and also at the contract price per square meter for place asphalt concrete (miscellaneous area). Full compensation for any necessary excavation, backfill and preparation of the area shall be considered as included in the contract price paid per square meter for place asphalt concrete (miscellaneous area) and no additional compensation will be allowed therefor.When there is no item for place asphalt concrete dike by the meter or for place asphalt concrete (miscellaneous area) by the square meter and the work is shown on the plans, full compensation therefor, including any necessary excavation, backfill, and preparation of the area, shall be considered as included in the contract price paid for the asphalt concrete.

Quantities of pavement reinforcing fabric placed and paving asphalt applied as a binder for the pavement reinforcing fabric will be paid for at the contract price per square meter for pavement reinforcing fabric and per tonne for paving asphalt (binder-pavement reinforcing fabric). Full compensation for furnishing and spreading sand to cover exposed binder material, if necessary, shall be considered as included in the contract price paid per tonne for paving asphalt (binder-pavement reinforcing fabric) and no separate payment will be made therefor.

Small quantities of asphalt concrete placed on pavement reinforcing fabric to prevent the fabric from being displaced by construction equipment or to allow traffic to cross over the fabric, shall be considered as part of the layer of asphalt concrete to be placed over the fabric and will be measured and paid for by the tonne as asphalt concrete.

When there is a contract item for liquid asphalt (prime coat), the quantity of prime coat will be paid for at the contract price per tonne for the designated grade of liquid asphalt (prime coat). When there is no contract item for liquid asphalt (prime coat) and the special provisions require the application of prime coat, full compensation for furnishing and applying prime coat shall be considered as included in the contract price paid per tonne for the asphalt concrete, and no separate payment will be made therefor.

When there is a contract item for asphaltic emulsion (paint binder), the quantity of asphaltic emulsion or paving asphalt used as paint binder (tack coat) will be paid for at the contract price per tonne for asphaltic emulsion (paint binder). When there is no contract item for asphaltic emulsion (paint binder), full compensation for furnishing and applying paint binder (tack coat) shall be considered as included in the contract price paid per tonne for the asphalt concrete, and no separate payment will be made therefor.

Fog seal coat will be paid for as provided in Section 37-1, "Seal Coats." No adjustment of compensation will be made for any increase or decrease in the quantities of paint binder (tack coat) or fog seal coat required, regardless of the reason for the increase or decrease. The provisions in Section 4-1.03B, "Increased or Decreased Quantities," shall not apply to the items of paint binder or fog seal coat.

The above contract prices and payments shall include full compensation for furnishing all labor, materials, tools, equipment, and incidentals, and for doing all the work involved in constructing asphalt concrete and asphalt concrete base, complete in place, as shown on the plans and as specified in these specifications and the special provisions, and as directed by the Engineer.