Attachment N - UFGS 32 12 16 Hot-Mix Asphalt HMA for Roads.pdf

SECTION 32 12 16 Page 1

SECTION TABLE OF CONTENTS

DIVISION 32 - EXTERIOR IMPROVEMENTS

SECTION 32 12 16

HOT-MIX ASPHALT (HMA) FOR ROADS

08/09

Table of Contents

PART 1 GENERAL

1.1 UNIT PRICES .......................... Error! Bookmark not defined.

1.2 REFERENCES

1.3 SUBMITTALS

1.4 ENVIRONMENTAL REQUIREMENTS

PART 2 PRODUCTS

2.1 SYSTEM DESCRIPTION

2.2 AGGREGATES

2.3 ASPHALT CEMENT BINDER

2.4 MIX DESIGN

2.5 RECYCLED HOT MIX ASPHALT

PART 3 EXECUTION

3.1 PREPARATION OF ASPHALT BINDER MATERIAL

3.2 PREPARATION OF MINERAL AGGREGATE

3.3 PREPARATION OF HOT-MIX ASPHALT MIXTURE

3.4 PREPARATION OF THE UNDERLYING SURFACE

3.5 TEST SECTION ......................... Error! Bookmark not defined.

3.6 TESTING LABORATORY

3.7 TRANSPORTING AND PLACING

3.8 COMPACTION OF MIXTURE

3.9 JOINTS

3.10 QUALITY CONTROL

3.11 MATERIAL ACCEPTANCE

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SECTION 32 12 16

HOT-MIX ASPHALT (HMA) FOR ROADS

08/09

PART 1 GENERAL.

1.1 REFERENCES.

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS

(AASHTO)

AASHTO M 156 (2013; R 2017) Standard Specification for

Requirements for Mixing Plants for

Hot-Mixed, Hot-Laid Bituminous Paving

Mixtures

AASHTO M 320 (2017) Standard Specification for

Performance-Graded Asphalt Binder

AASHTO T 304 (2011; R 2015) Standard Method of Test for

Uncompacted Void Content of Fine Aggregate

ASPHALT INSTITUTE (AI)

AI MS-2 (2015) Asphalt Mix Design Methods

AI MS-22 (2001; 2nd Ed) Construction of Hot-Mix

Asphalt Pavements

AI SP-2 (2001; 3rd Ed) Superpave Mix Design

ASTM INTERNATIONAL (ASTM)

ASTM C29/C29M (2017a) Standard Test Method for Bulk

Density ("Unit Weight") and Voids in

Aggregate

ASTM C88 (2018) Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or

Magnesium Sulfate

ASTM C117 (2017) Standard Test Method for Materials

Finer than 75-um (No. 200) Sieve in

Mineral Aggregates by Washing

ASTM C127 (2015) Standard Test Method for Density, Relative Density (Specific Gravity), and

Absorption of Coarse Aggregate

ASTM C128 (2015) Standard Test Method for Density, Relative Density (Specific Gravity), and

Absorption of Fine Aggregate

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ASTM C131/C131M (2020) Standard Test Method for Resistance to Degradation of Small-Size Coarse

Aggregate by Abrasion and Impact in the

Los Angeles Machine

ASTM C136/C136M (2019) Standard Test Method for Sieve

Analysis of Fine and Coarse Aggregates

ASTM C142/C142M (2017) Standard Test Method for Clay Lumps and Friable Particles in Aggregates

ASTM C566 (2013) Standard Test Method for Total

Evaporable Moisture Content of Aggregate by Drying

ASTM D140/D140M (2016) Standard Practice for Sampling

Asphalt Materials

ASTM D242/D242M (2009; R 2014) Mineral Filler for

Bituminous Paving Mixtures

ASTM D946/D946M (2020) Standard Specification for

Penetration-Graded Asphalt Cement for Use in Pavement Construction

ASTM D1461 (2017) Standard Test Method for Moisture or Volatile Distillates in Asphalt Mixtures

ASTM D2041/D2041M (2011) Theoretical Maximum Specific

Gravity and Density of Bituminous Paving

Mixtures

ASTM D2172/D2172M (2017; E 2018) Standard Test Methods for

Quantitative Extraction of Asphalt Binder from Asphalt Mixtures

ASTM D2419 (2014) Sand Equivalent Value of Soils and

Fine Aggregate

ASTM D2489/D2489M (2016) Standard Test Method for Estimating

Degree of Particle Coating of Asphalt

Mixtures

ASTM D2726/D2726M (2019) Standard Test Method for Bulk

Specific Gravity and Density of

Non-Absorptive Compacted Bituminous

Mixtures

ASTM D2950/D2950M (2014) Density of Bituminous Concrete in

Place by Nuclear Methods

ASTM D3381/D3381M (2018) Standard Specification for

Viscosity-Graded Asphalt Binder for Use in

Pavement Construction

ASTM D3665 (2012; R 2017) Standard Practice for

Random Sampling of Construction Materials

ASTM D3666 (2016) Standard Specification for Minimum

Requirements for Agencies Testing and

Inspecting Road and Paving Materials

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ASTM D4125/D4125M (2010) Asphalt Content of Bituminous

Mixtures by the Nuclear Method

ASTM D4791 (2019) Flat Particles, Elongated

Particles, or Flat and Elongated Particles in Coarse Aggregate

ASTM D4867/D4867M (2009; R 2014) Effect of Moisture on

Asphalt Concrete Paving Mixtures

ASTM D5444 (2015) Mechanical Size Analysis of

Extracted Aggregate

ASTM D6307 (2019) Standard Test Method for Asphalt

Content of Asphalt Mixture by Ignition

Method

ASTM D6925 (2014) Standard Test Method for

Preparation and Determination of the

Relative Density of Hot Mix Asphalt (HMA)

Specimens by Means of the Superpave

Gyratory Compactor

ASTM D6926 (2020) Standard Practice for Preparation of Asphalt Mixture Specimens Using

Marshall Apparatus

ASTM D6927 (2015) Standard Test Method for Marshall

Stability and Flow of Bituminous Mixtures

STATE OF CALIFORNIA DEPARTMENT OF TRANSPORTATION (CALTRANS)

CTM 526 (2012) Method of Test for Operation of

California Profilograph and Evaluation of

Profiles

U.S. ARMY CORPS OF ENGINEERS (USACE)

COE CRD-C 171 (1995) Standard Test Method for

Determining Percentage of Crushed

Particles in Aggregate

1.2 SUBMITTALS.

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the government officer that will review the submittal for the Government.

SD-03 Product Data

Mix Design; G, COR

Quality Control; G, COR

Material Acceptance; G, COR

SD-04 Samples

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Asphalt Cement Binder

Aggregates

SD-06 Test Reports

Aggregates; G, COR

QC Monitoring

SD-07 Certificates

Asphalt Cement Binder; G, COR

Testing Laboratory

1.3 ENVIRONMENTAL REQUIREMENTS.

Do not place the hot-mix asphalt upon a wet surface or when the surface temperature of the underlying course is less than specified in Table 3.

The temperature requirements may be waived by the Contracting Officer, if requested; however, meet all other requirements, including compaction.

Table 3. Surface Temperature Limitations of Underlying Course

Mat Thickness, mm inches Degrees C F

75 3 or greater 4 40

Less than 75 3 7 45

PART 2 PRODUCTS.

2.1 SYSTEM DESCRIPTION.

Perform the work consisting of pavement courses composed of mineral aggregate and asphalt material heated and mixed in a central mixing plant and placed on a prepared course. HMA designed and constructed in accordance with this section shall conform to the lines, grades, thicknesses, and typical cross sections indicated. Construct each course to the depth, section, or elevation required by the drawings and roll, finish, and approve it before the placement of the next course.

2.1.1 Asphalt Mixing Plant

Plants used for the preparation of hot-mix asphalt shall conform to the requirements of AASHTO M 156 with the following changes:

2.1.1.1 Truck Scales

Weigh the asphalt mixture on approved, certified scales at the

Contractor's expense. Inspect and seal scales at least annually by an approved calibration laboratory.

2.1.1.2 Inspection of Plant

Provide the Contracting Officer with access at all times, to all areas of

SECTION 32 12 16 Page 6 the plant for checking adequacy of equipment; inspecting operation of the plant; verifying weights, proportions, and material properties; checking the temperatures maintained in the preparation of the mixtures and for taking samples. Provide assistance as requested, for the Government to procure any desired samples.

2.1.1.3 Storage bins

Use of storage bins for temporary storage of hot-mix asphalt will be permitted as follows:

a. The asphalt mixture may be stored in non-insulated storage bins for a period of time not exceeding 3 hours.

b. The asphalt mixture may be stored in insulated storage bins for a period of time not exceeding 8 hours. The mix drawn from bins shall meet the same requirements as mix loaded directly into trucks.

2.1.2 Hauling Equipment

Provide trucks for hauling hot-mix asphalt having tight, clean, and smooth metal beds. To prevent the mixture from adhering to them, the truck beds shall be lightly coated with a minimum amount of paraffin oil, lime solution, or other approved material. Petroleum based products shall not be used as a release agent. Each truck shall have a suitable cover to protect the mixture from adverse weather. When necessary to ensure that the mixture will be delivered to the site at the specified temperature, truck beds shall be insulated or heated and covers (tarps) shall be securely fastened.

2.1.3 Asphalt Pavers

Provide asphalt pavers which are self-propelled, with an activated screed, heated as necessary, and capable of spreading and finishing courses of hot-mix asphalt which will meet the specified thickness, smoothness, and grade. The paver shall have sufficient power to propel itself and the hauling equipment without adversely affecting the finished surface.

2.1.3.1 Receiving Hopper

Provide paver with a receiving hopper of sufficient capacity to permit a uniform spreading operation and equipped with a distribution system to place the mixture uniformly in front of the screed without segregation.

The screed shall effectively produce a finished surface of the required evenness and texture without tearing, shoving, or gouging the mixture.

2.1.3.2 Automatic Grade Controls

Equip the paver with a control system capable of automatically maintaining the specified screed elevation. The control system shall be automatically actuated from either a reference line and/or through a system of mechanical sensors or sensor-directed mechanisms or devices which will maintain the paver screed at a predetermined transverse slope and at the proper elevation to obtain the required surface. The transverse slope controller shall be capable of maintaining the screed at the desired slope within plus or minus 0.1 percent. A transverse slope controller shall not be used to control grade. Provide controls capable of working in conjunction with any of the following attachments:

a. Ski-type device of not less than 9.14 m 30 feet in length.

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b. Taut stringline set to grade.

c. Short ski or shoe for joint matching.

d. Laser control.

2.1.4 Rollers

Rollers shall be in good condition and shall be operated at slow speeds to avoid displacement of the asphalt mixture. The number, type, and weight of rollers shall be sufficient to compact the mixture to the required density while it is still in a workable condition. Do not use equipment which causes excessive crushing of the aggregate.

2.2 AGGREGATES.

Aggregates. Provide aggregates consisting of crushed stone, crushed gravel, crushed slag, screenings, natural sand and mineral filler, as required. The portion of material retained on the No. 4 sieve is coarse aggregate. The portion of material passing the No. 4 sieve and retained on the No. 200 sieve is fine aggregate. The portion passing the No. 200 sieve is defined as mineral filler. Submit all aggregate test results to the Contracting Officer at least 14 days prior to start of construction.

2.2.1 Coarse Aggregate

Provide coarse aggregate consisting of sound, tough, durable particles, free from films of material that would prevent thorough coating and bonding with the asphalt material and free from organic matter and other deleterious substances. All individual coarse aggregate sources shall meet the following requirements:

a. The percentage of loss shall not be greater than 40 percent after 500 revolutions when tested in accordance with ASTM C131/C131M.

b. The percentage of loss shall not be greater than 18 percent after five cycles when tested in accordance with ASTM C88 using magnesium sulfate or 12 percent when using sodium sulfate.

c. At least 75 percent by weight of coarse aggregate shall have at least two or more fractured faces when tested in accordance with

COE CRD-C 171. Fractured faces shall be produced by crushing.

d. The particle shape shall be essentially cubical and the aggregate shall not contain more than 20 percent percent, by weight, of flat and elongated particles (3:1 ratio of maximum to minimum) when tested in accordance with ASTM D4791.

e. Slag shall be air-cooled, blast furnace slag, with a compacted weight of not less than 75 lb/cu ft when tested in accordance with ASTM

C29/C29M.

f. Clay lumps and friable particles shall not exceed 0.3 percent, by weight, when tested in accordance with ASTM C142/C142M.

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2.2.2 Fine Aggregate

Fine aggregate shall consist of clean, sound, tough, durable particles free from coatings of clay, silt, or any objectionable material and containing no clay balls.

a. All individual fine aggregate sources shall have a sand equivalent value not less than 45 when tested in accordance with ASTM D2419.

b. The fine aggregate portion of the blended aggregate shall have an uncompacted void content not less than 45.0 percent when tested in accordance with AASHTO T 304 Method A.

c. The quantity of natural sand (noncrushed material) added to the aggregate blend shall not exceed 25 percent by weight of total aggregate.

d. Clay lumps and friable particles shall not exceed 0.3 percent, by weight, when tested in accordance with ASTM C142/C142M

2.2.3 Mineral Filler

Mineral filler shall be nonplastic material meeting the requirements of

ASTM D242/D242M.

2.2.4 Aggregate Gradation

The combined aggregate gradation shall conform to gradations specified in

Table 4, when tested in accordance with ASTM C136/C136M and ASTM C117, and shall not vary from the low limit on one sieve to the high limit on the adjacent sieve or vice versa, but grade uniformly from coarse to fine.

Table 4. Aggregate Gradations

Sieve Size, inch

Gradation 1

Percent

Passing by

Mass

Gradation 2

Percent

Passing by

Mass

Gradation 3

Percent

Passing by

Mass

1 100 --- ---

3/4 76-96 100 ---

1/2 68-88 76-96 100

3/8 60-82 69-89 76-96

No. 4 45-67 53-73 58-78

No. 8 32-54 38-60 40-60

No. 16 22-44 26-48 28-48

No. 30 15-35 18-38 18-38

No. 50 9-25 11-27 11-27

No. 100 6-18 6-18 6-18

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No. 200 3-6 3-6 3-6

2.3 ASPHALT CEMENT BINDER.

Provide asphalt cement binder that conforms to AASHTO M 320 Performance

Grade (PG) 64-22. Provide test data indicating grade certification by the supplier at the time of delivery of each load to the mix plant. Submit copies of these certifications to the Government within 24hrs of delivery.

The supplier is defined as the last source of any modification to the binder.

2.4 MIX DESIGN.

a. Develop the mix design for approval and perform Job Mix formula (JMF) and aggregates testing prior to construction. Provide asphalt mix composed of a mixture of well-graded aggregate, mineral filler if required, and asphalt material. Provide aggregate fractions sized, handled in separate size groups, and combined in such proportions that the resulting mixture meets the grading requirements of Table 5.

Design the hot-mix asphalt using the Superpave gyratory compactor set at 50 gyrations for all shoulder pavements and 75 gyrations for all taxiway and overrun pavements. Prepare samples at various asphalt contents and compacted in accordance with ASTM D6925. Use laboratory compaction temperatures for Polymer Modified Asphalts as recommended by the asphalt cement manufacturer. If the Tensile Strength Ratio

(TSR) of the composite mixture, as determined by ASTM D4867/D4867M is less than 75, reject the aggregates or the asphalt mixture treated with an anti-stripping agent. Add a sufficient amount of anti-stripping agent to produce a TSR of not less than 75. If an antistrip agent is required, provided it at no additional cost to the

Government.

b. At the option of the Contractor, a currently used DOT Superpave hot mix may be used in lieu of developing a Marshall hot mix design as described herein. Design the Superpave volumetric mix in accordance with AI SP-2 and ASTM D6925. The nominal maximum aggregate size (NMAS) shall be 3/8 inch. Other DOT hot mix design methods (Hveem, etc.) may be suitable, as determined by the Contracting Officer. The number of compaction gyrations, Ndes, shall be based on a design traffic of 5.9

Million equivalent single axle loads (EASLs).

c. Design Superpave mixes with the number of gyrations specified in Table 5,

d. If DOT option is chosen by engineer, contractor shall produce a Job Mix Formula using DOT specifications. The Engineer/COR may accept a design previously used on a DOT project. Do not produce hot-mix asphalt until a JMF has been submitted and approved by Engineer/COR.

e. If adjustments are made to Field Job Mix Formula, the Contractor shall submit new JMF for approval before the new material is used.

2.4.1 JMF Requirements

Submit in writing the job mix formula for approval at least 14 days prior to

SECTION 32 12 16 Page 10 the start of the test section including as a minimum:

a. Percent passing each sieve size.

b. Percent of asphalt cement.

c. Percent of each aggregate and mineral filler to be used.

d. Asphalt viscosity grade, penetration grade, or performance grade.

e. Number of blows of hand-held hammer per side of molded specimen. (NA for Superpave)

f. Number of gyrations of Superpave gyratory compactor, (N/A for Marshall mix design)

g. Laboratory mixing temperature.

h. Lab compaction temperature.

i. Temperature-viscosity relationship of the asphalt cement.

j. Plot of the combined gradation on the 0.45 power gradation chart, stating the nominal maximum size.

k. Graphical plots of stability (NA for Superpave), flow (NA for Superpave), air voids, voids in the mineral aggregate, and unit weight versus asphalt content as shown in AI MS-2.

l. Specific gravity and absorption of each aggregate.

m. Percent natural sand.

n. Percent particles with 2 or more fractured faces (in coarse aggregate).

o. Fine aggregate angularity.

p. Percent flat or elongated particles (in coarse aggregate).

q. Tensile Strength Ratio(TSR).

r. Antistrip agent (if required) and amount.

s. List of all modifiers and amount.

t. Correlation of hand-held hammer with mechanical hammer (NA for

Superpave).

2.4.2 Adjustments to Field JMF

JMF for each mixture is in effect until a new formula is approved in writing by the Government. Should a change in sources of any materials be made, perform a new mix design and a new JMF approved before the new material is used. Make minor adjustments within the specification limits to the JMF to optimize mix volumetric properties. Adjustments to the original JMF are limited to plus or minus 4 percent on the No. 4 and coarser sieves; plus or minus 3 percent on the No. 8 to No. 50 sieves; and plus or minus 1 percent on the No. 100 sieve. Adjustments to the JMF are limited to plus or minus

1.0 percent on the No. 200 sieve. Asphalt content adjustments are limited to plus or minus 0.40 from the original JMF. If adjustments are needed that exceed these limits, develop a new mix design.

2.5 RECYCLED HOT MIX ASPHALT.

Recycled HMA not allowed.

PART 3 EXECUTION.

3.1 PREPARATION OF ASPHALT BINDER MATERIAL.

Heat the asphalt cement material avoiding local overheating and providing a continuous supply of the asphalt material to the mixer at a uniform temperature. The temperature of unmodified asphalts shall be no more than

325 degrees F when added to the aggregates. Performance-Graded (PG) asphalts shall be within the temperature range of 5 degrees F when added to the aggregate.

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3.2 PREPARATION OF MINERAL AGGREGATE.

Heat and dry the aggregate for the mixture prior to mixing. No damage shall occur to the aggregates due to the maximum temperature and rate of heating used. The temperature of the aggregate and mineral filler shall not exceed 350 degrees F when the asphalt cement is added. The temperature shall not be lower than is required to obtain complete coating and uniform distribution on the aggregate particles and to provide a mixture of satisfactory workability.

3.3 PREPARATION OF HOT-MIX ASPHALT MIXTURE.

The aggregates and the asphalt cement shall be weighed or metered and introduced into the mixer in the amount specified by the JMF. Mix the combined materials until the aggregate obtains a uniform coating of asphalt binder and is thoroughly distributed throughout the mixture. Wet mixing time shall be the shortest time that will produce a satisfactory mixture, but no less than 25 seconds for batch plants. Establish the wet mixing time for all plants based on the procedure for determining the percentage of coated particles described in ASTM D2489/D2489M, for each individual plant and for each type of aggregate used. The wet mixing time will be set to at least achieve 95 percent of coated particles. The moisture content of all hot-mix asphalt upon discharge from the plant shall not exceed 0.5 percent by total weight of mixture as measured by

ASTM D1461.

3.4 PREPARATION OF THE UNDERLYING SURFACE.

Immediately before placing the hot mix asphalt, clean the underlying course of dust and debris. Apply a prime and tack coat in accordance with the contract specifications.

3.5 TESTING LABORATORY.

Submit certification of compliance and Plant Scale Calibration

Certification. Use a laboratory to develop the JMF that meets the requirements of ASTM D3666. The Government will inspect the laboratory equipment and test procedures prior to the start of hot mix operations for conformance to ASTM D3666. The laboratory shall maintain the Corps certification for the duration of the project. A statement signed by the manager of the laboratory stating that it meets these requirements or clearly listing all deficiencies shall be submitted to the Contracting

Officer prior to the start of construction. The statement shall contain as a minimum:

a. Qualifications of personnel; laboratory manager, supervising technician, and testing technicians.

b. A listing of equipment to be used in developing the job mix.

c. A copy of the laboratory's quality control system.

d. Evidence of participation in the AASHTO Materials Reference Laboratory

(AMRL) program.

3.6 TRANSPORTING AND PLACING.

3.6.1 Transporting

Transport the hot-mix asphalt from the mixing plant to the site in clean, SECTION 32 12 16 Page 12 tight vehicles. Schedule deliveries so that placing and compacting of mixture is uniform with minimum stopping and starting of the paver.

Provide adequate artificial lighting for night placements. Hauling over freshly placed material will not be permitted until the material has been compacted as specified, and allowed to cool to 60 degrees C 140 degrees F. To deliver mix to the paver, use a material transfer vehicle operated to produce continuous forward motion of the paver.

3.6.2 Placing

Place and compact the mix at a temperature suitable for obtaining density, surface smoothness, and other specified requirements. Upon arrival, place the mixture to the full width by an asphalt paver; it shall be struck off in a uniform layer of such depth that, when the work is completed, it will have the required thickness and conform to the grade and contour indicated. Regulate the speed of the paver to eliminate pulling and tearing of the asphalt mat. Unless otherwise permitted, placement of the mixture shall begin along the centerline of a crowned section or on the high side of areas with a one-way slope. Place the mixture in consecutive adjacent strips having a minimum width of 10 feet. The longitudinal joint in one course shall offset the longitudinal joint in the course immediately below by at least 1 foot; however, the joint in the surface course shall be at the centerline of the pavement. Transverse joints in one course shall be offset by at least 3 m 10 feet from transverse joints in the previous course. Transverse joints in adjacent lanes shall be offset a minimum of 10 feet. On isolated areas where irregularities or unavoidable obstacles make the use of mechanical spreading and finishing equipment impractical, the mixture may be spread and luted by hand tools.

3.7 COMPACTION OF MIXTURE.

After placing, the mixture shall be thoroughly and uniformly compacted by rolling. Compact the surface as soon as possible without causing displacement, cracking or shoving. The sequence of rolling operations and the type of rollers used shall be at the discretion of the Contractor.

The speed of the roller shall, at all times, be sufficiently slow to avoid displacement of the hot mixture and be effective in compaction. Any displacement occurring as a result of reversing the direction of the roller, or from any other cause, shall be corrected at once. Furnish sufficient rollers to handle the output of the plant. Continue rolling until the surface is of uniform texture, true to grade and cross section, and the required field density is obtained. To prevent adhesion of the mixture to the roller, keep the wheels properly moistened but excessive water will not be permitted. In areas not accessible to the roller, the mixture shall be thoroughly compacted with hand tampers. Any mixture that becomes loose and broken, mixed with dirt, contains check-cracking, or is in any way defective shall be removed full depth, replaced with fresh hot mixture and immediately compacted to conform to the surrounding area.

This work shall be done at the Contractor's expense. Skin patching will not be allowed.

3.8 JOINTS.

The formation of joints shall be performed ensuring a continuous bond between the courses and to obtain the required density. All joints shall have the same texture as other sections of the course and meet the requirements for smoothness and grade.

SECTION 32 12 16 Page 13

3.8.1 Transverse Joints

Do not pass the roller over the unprotected end of the freshly laid mixture, except when necessary to form a transverse joint. When necessary to form a transverse joint, it shall be made by means of placing a bulkhead or by tapering the course. The tapered edge shall be cut back to its full depth and width on a straight line to expose a vertical face prior to placing material at the joint. Remove the cutback material from the project. In both methods, all contact surfaces shall be given a light tack coat of asphalt material before placing any fresh mixture against the joint.

3.8.2 Longitudinal Joints

Longitudinal joints which are irregular, damaged, uncompacted, cold (less than 175 degrees F at the time of placing adjacent lanes), or otherwise defective, shall be cut back a maximum of 3 inches from the top of the course with a cutting wheel to expose a clean, sound vertical surface for the full depth of the course. All cutback material shall be removed from the project. All contact surfaces shall be given a light tack coat of asphalt material prior to placing any fresh mixture against the joint.

The Contractor will be allowed to use an alternate method if it can be demonstrated that density, smoothness, and texture can be met.

3.9 QUALITY CONTROL.

3.9.1 General Quality Control Requirements

Develop and submit an approved Quality Control Plan. Submit aggregate and QC test results within 24hr of test completion. Do not produce hot-mix asphalt until the quality control plan has been approved addressing all elements which affect the quality of the pavement including, but not limited to:

a. Mix Design

b. Aggregate Grading

c. Quality of Materials

d. Stockpile Management

e. Proportioning

f. Mixing and Transportation

g. Mixture Volumetrics

h. Moisture Content of Mixtures

i. Placing and Finishing

SECTION 32 12 16 Page 14

j. Joints

k. Compaction

l. Surface Smoothness

3.9.2 Quality Control Testing

Perform all quality control tests applicable to these specifications and as set forth in the Quality Control Program. The testing program shall include, but shall not be limited to, tests for the control of asphalt content, aggregate gradation, temperatures, aggregate moisture, moisture in the asphalt mixture, laboratory air voids, stability (NA for

Superpave), flow (NA for Superpave), in-place density, grade and smoothness. Develop a Quality Control Testing Plan as part of the Quality

Control Program.

3.10.3.1 Asphalt Content

A minimum of two tests to determine asphalt content will be performed per lot (a lot is defined in paragraph MATERIAL ACCEPTANCE and PERCENT

PAYMENT) by one of the following methods: the extraction method in accordance with ASTM D2172/D2172M, Method A or B, the ignition method in accordance with ASTM D6307, or the nuclear method in accordance with

ASTM D4125/D4125M. Calibrate the ignition oven or the nuclear gauge for the specific mix being used. For the extraction method, determine the weight of ash, as described in ASTM D2172/D2172M, as part of the first extraction test performed at the beginning of plant production; and as part of every tenth extraction test performed thereafter, for the duration of plant production. The last weight of ash value obtained shall be used in the calculation of the asphalt content for the mixture.

3.10.3.2 Gradation

Determine aggregate gradations a minimum of twice per lot from mechanical analysis of recovered aggregate in accordance with ASTM D5444. When asphalt content is determined by the ignition oven or nuclear method, aggregate gradation shall be determined from hot bin samples on batch plants, or from the cold feed on drum mix plants. For batch plants, test aggregates in accordance with ASTM C136/C136M using actual batch weights to determine the combined aggregate gradation of the mixture.

3.10.3.3 Temperatures

Check temperatures at least four times per lot, at necessary locations, to determine the temperature at the dryer, the asphalt cement in the storage tank, the asphalt mixture at the plant, and the asphalt mixture at the job site.

3.10.3.4 Aggregate Moisture

Determine the moisture content of aggregate used for production a minimum of once per lot in accordance with ASTM C566.

3.10.3.5 Moisture Content of Mixture

Determine the moisture content of the mixture at least once per lot in accordance with ASTM D1461 or an approved alternate procedure.

SECTION 32 12 16 Page 15

3.10.3.6 Laboratory Air Voids, Marshall Stability and Flow

Take mixture samples at least four times per lot compacted into specimens, using 50blows per side with the hand-held Marshall hammer as described in

ASTM D6926. When the Superpave gyratory compactor is used, mixes will be compacted to 50 gyrations in accordance with ASTM D6925. Hot-mix provided under the DOT Superpave option shall be tested in accordance with the DOT requirements. After compaction, determine the laboratory air voids of each specimen. Stability and flow shall be determined for the Marshall-compacted specimens, in accordance with ASTM D6927.

3.10.3.7 In-Place Density

Conduct any necessary testing to ensure the specified density is achieved. A nuclear gauge may be used to monitor pavement density in accordance with ASTM D2950/D2950M.

3.10.3.8 Grade and Smoothness

Conduct the necessary checks to ensure the grade and smoothness requirements are met in accordance with paragraphs MATERIAL ACCEPTANCE and

PERCENT PAYMENT.

3.10.3.9 Additional Testing

Any additional testing, which the Contractor deems necessary to control the process, may be performed at the Contractor's option.

3.10.3.10 QC Monitoring

Submit all QC test results to the Contracting Officer on a daily basis as the tests are performed. The Contracting Officer reserves the right to monitor any of the Contractor's quality control testing and to perform duplicate testing as a check to the Contractor's quality control testing.

3.9.3 Sampling

When directed by the Contracting Officer, sample and test any material which appears inconsistent with similar material being produced, unless such material is voluntarily removed and replaced or deficiencies corrected by the Contractor. All sampling shall be in accordance with standard procedures specified.

3.9.4 Control Charts

For process control, establish and maintain linear control charts on both individual samples and the running average of last four samples for the parameters listed in Table 8, as a minimum. These control charts shall be posted as directed by the Contracting Officer and kept current at all times. The control charts shall identify the project number, the test parameter being plotted, the individual sample numbers, the Action and

Suspension Limits listed in Table 8 applicable to the test parameter being plotted, and the Contractor's test results. Target values from the JMF shall also be shown on the control charts as indicators of central tendency for the cumulative percent passing, asphalt content, and laboratory air voids parameters. When the test results exceed either applicable Action Limit, take immediate steps to bring the process back in control. When the test results exceed either applicable Suspension Limit, halt production until the problem is solved. Use the control charts as part of the process control system for identifying trends so that potential problems can be corrected before they occur. Make decisions

SECTION 32 12 16 Page 16 concerning mix modifications based on analysis of the results provided in the control charts. The Quality Control Plan shall indicate the appropriate action to be taken to bring the process into control when certain parameters exceed their Action Limits.

Table 8. Action and Suspension Limits for the

Parameters to be Plotted on

Individual and Running Average Control

Charts

Individual Samples Running Average of

Last Four Samples

Parameter to be Plotted Action

Limi t

Suspension

Limit

Action

Limi t

Suspension

Limit

No. 4 sieve, Cumulative percent passing, deviation for

JMF

target; plus or minus values

6 8 4 5

No. 30 sieve, Cumulative percent passing, deviation for

JMF

target; plus or minus values

4 6 3 4

No. 200 sieve, Cumulative percent passing, deviation for

JMF

target; plus or minus values

1.4 2.0 1.1 1.5

Stability, pounds (minimum) (NA for Superpave)

75 Blow JMF 1800 1700 1900 1800

50 Blow JMF 1000 900 1100 1000

Flow, 0.01 in (NA for Superpave)

75 Blow JMF 8 min. 7 min. 9 min. 8 min.

16 max. 17 max. 15 max. 16 max.

50 Blow JMF 8 min. 7 min. 9 min. 8 min.

16 max. 19 max. 17 max. 18 max.

Asphalt content, percent deviation from JMF target; plus or minus value

0.4 0.5 0.2 0.3

Laboratory Air Voids, percent deviation from JMF target value

No specific action and suspension limits set

3.10 MATERIAL ACCEPTANCE.

Testing for acceptability of work will be performed by an independent laboratory hired by the Contractor. Forward test results daily to the

Contracting Officer. Acceptance of the plant produced mix and in-place requirements will be on a lot to lot basis. A standard lot for all

SECTION 32 12 16 Page 17 requirements will be equal to 8 hours of production. Grade and surface smoothness determinations will be made on the lot as a whole. Exceptions or adjustments to this will be made in situations where the mix within one lot is placed as part of both the intermediate and surface courses, thus grade and smoothness measurements for the entire lot cannot be made. In order to evaluate laboratory air voids and in-place (field) density, each lot will be divided into four equal sublots.

3.10.1 Sublot Sampling

One random mixture sample for determining laboratory air voids, theoretical maximum density, and for any additional testing the

Contracting Officer desires, will be taken from a loaded truck delivering mixture to each sublot, or other appropriate location for each sublot.

All samples will be selected randomly, using commonly recognized methods of assuring randomness conforming to ASTM D3665 and employing tables of random numbers or computer programs. Laboratory air voids will be determined from three laboratory compacted specimens of each sublot sample in accordance with ASTM D6926. The specimens will be compacted within 2 hours of the time the mixture was loaded into trucks at the asphalt plant. Samples will not be reheated prior to compaction and insulated containers will be used as necessary to maintain the temperature.

3.10.2 Grade

The final wearing surface of pavement shall conform to the elevations and cross sections shown and shall vary not more than 0.05 foot from the plan grade established and approved at site of work. Finished surfaces at juncture with other pavements shall coincide with finished surfaces of abutting pavements. Deviation from the plan elevation will not be permitted in areas of pavements where closer conformance with planned elevation is required for the proper functioning of drainage and other appurtenant structures involved. The grade will be determined by running lines of levels at intervals of 25 feet, or less, longitudinally and transversely, to determine the elevation of the completed pavement surface. Within 5 working days, after the completion of a particular lot incorporating the final wearing surface, test the final wearing surface of the pavement for conformance with the specified plan grade. Diamond grinding may be used to remove high spots to meet grade requirements.

Skin patching for correcting low areas or planing or milling for correcting high areas will not be permitted.

3.10.3 Surface Smoothness

Use one of the following methods to test and evaluate surface smoothness of the pavement. Perform all testing in the presence of the Contracting

Officer. Keep detailed notes of the results of the testing and furnish a copy to the Government immediately after each day's testing. [Use the profilograph method for all longitudinal testing, except where the runs would be less than 200 feet in length and the ends where the straightedge will be used.] Where drawings show required deviations from a plane surface (crowns, drainage inlets, etc.), the surface shall be finished to meet the approval of the Contracting Officer.

3.11.4.1 Smoothness Requirements

3.11.4.1.1 Straightedge Testing

The finished surfaces of the pavements shall have no abrupt change of 1/4 inch or more, and all pavements shall be within the tolerances of 1/4 inch in both the longitudinal and transverse directions, when tested with an

SECTION 32 12 16 Page 18 approved 12 feet straightedge.

3.11.4.1.2 Profilograph Testing

The finished surfaces of the pavements shall have no abrupt change of 3 mm

1/8 inch or more, and each 0.1 mile segment of each pavement lot shall have a Profile Index not greater than 9 inches/mile when tested with an approved California-type profilograph. If the extent of the pavement in either direction is less than 200 feet, that direction shall be tested by the straightedge method and shall meet requirements specified above.

3.11.4.2 Testing Method

After the final rolling, but not later than 24 hours after placement, test the surface of the pavement in each entire lot in such a manner as to reveal all surface irregularities exceeding the tolerances specified above. Separate testing of individual sublots is not required. If any pavement areas are ground, these areas shall be retested immediately after grinding. Test each lot of the pavement in both a longitudinal and a transverse direction on parallel lines. Set the transverse lines 15 feet or less apart, as directed. The longitudinal lines shall be at the centerline of each paving lane for lanes less than 20 feet wide and at the third points for lanes 20 feet or wider. Also test other areas having obvious deviations. Longitudinal testing lines shall be continuous across all joints.

3.11.4.2.1 Straightedge Testing

Hold the straightedge in contact with the surface and move it ahead one-half the length of the straightedge for each successive measurement.

Determine the amount of surface irregularity by placing the freestanding

(unleveled) straightedge on the pavement surface and allowing it to rest upon the two highest spots covered by its length, and measuring the maximum gap between the straightedge and the pavement surface in the area between these two high points.

3.11.4.2.2 Profilograph Testing

Perform profilograph testing using approved equipment and procedures described in CTM 526. The equipment shall utilize electronic recording and automatic computerized reduction of data to indicate "must-grind" bumps and the Profile Index for each 0.1 mile segment of each pavement lot.

Grade breaks on parking lots shall be accommodated by breaking the profile segment into shorter sections and repositioning the blanking band on each segment. The "blanking band" shall be 0.2 inches wide and the "bump template" shall span 1 inch with an offset of 0.3 inch. Compute the

Profile Index for each pass of the profilograph in each 0.1 mile segment.

The Profile Index for each segment shall be the average of the Profile

Indices for each pass in each segment. The profilograph shall be operated by a DOT approved operator. Furnish a copy of the reduced tapes to the

Government at the end of each day's testing.

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