### **ITEM P‑402 POROUS FRICTION COURSE**

**(Central Plant Hot Mix)**

DESCRIPTION

**402‑1.1** This item shall consist of a plant mixed, open-graded porous
friction course, composed of mineral aggregate and bituminous material,
mixed in a central mixing plant, and placed on a prepared surface in
accordance with these specifications and shall conform to the dimensions
and typical cross section as shown on the plans.

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> **The porous friction course (PFC) shall be designed as a free
> draining wearing surface of uniform thickness. The PFC must be placed
> on a prepared surface, which drains freely and does not allow ponding.
> The PFC should not be applied over an existing PFC. Any existing PFC
> should be removed and the entire surface leveled prior to placement of
> a new PFC.**

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MATERIALS

**402‑2.1 AGGREGATE**. The aggregate shall consist of crushed stone,
crushed gravel, or crushed slag with or without other inert finely
divided mineral aggregate. The aggregate shall be composed of clean,
sound, tough, durable particles, free from clay balls, organic matter,
and other deleterious substances. The portion of the material retained
on the No. 4 sieve shall be known as [coarse aggregate]{.underline}, the
portion passing the No. 4 sieve and retained on the No. 200 sieve as
[fine aggregate]{.underline}, and the portion passing the No. 200 sieve
as [mineral filler]{.underline}.

**a. Coarse Aggregate.** Coarse aggregate shall contain at least 75
percent by weight crushed pieces having two or more fractured faces and
100 percent by weight particles with one or more fractured faces. The
area of each face shall be equal to at least 75 percent of the smallest
mid-sectional area of the piece. When two fractures are contiguous, the
angle between the planes of fractures shall be at least 30 degrees to
count as two fractured faces. Fractured faces shall be obtained by
crushing. The coarse aggregate shall not contain more than 8 percent, by
weight of flat or elongated pieces as defined in ASTM D 693. The
percentage of wear shall not be greater than 30 percent when tested in
accordance with ASTM C 131. The sodium sulfate soundness loss shall not
exceed 12 percent after five cycles, when tested in accordance with ASTM
C 88.

**b. Fine Aggregate.** Fine aggregate shall have a plasticity index of
not more than 6.0 and a liquid limit of not more than 25 when tested in
accordance with ASTM D 4318. The percentage of wear shall not be greater
than 30 percent when tested in accordance with ASTM C 131. The sodium
sulfate soundness loss shall not exceed 12 percent after five cycles,
when tested in accordance with ASTM C 88.

If necessary, natural sand may be used to obtain the gradation of
aggregate blend or workability. The amount of sand to be added will be
adjusted to produce mixtures conforming to requirements of this
specification.

**402‑2.2 FILLER**. If filler, in addition to that naturally present in
the aggregate, is necessary, it shall meet the requirements of ASTM D
242. When mineral filler is required to be batched separately, hydrated
lime in the amount of 1.5 percent maximum by weight of the total
aggregate shall be batched as part of the added mineral filler. No
additional compensation will be allowed the Contractor for furnishing
and using hydrated lime or other approved mineral filler that may be
required by this specification.

**402‑2.3 BITUMINOUS MATERIAL**. The bituminous material shall be
viscosity graded asphalt cement meeting Table 1 of this section and ASTM
D-3381, Table 2. A synthetic rubber additive shall be added to the
bitumen in an amount not less than 2 percent by weight (% by weight of
synthetic rubber solids). The bitumen and additive shall be uniformly
mixed to provide a mixture meeting the following requirements:

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**[FOR FAA CENTRAL REGION PROJECTS:]{.underline}**

  ---------------------------- ------------------------ ------------------------ ------------------------
  **TABLE 1**                                                                    

  **[Property]{.underline}**   **[ASTM]{.underline}**   **[Min.]{.underline}**   **[Max.]{.underline}**

  **Viscosity @ 140°F.,        **D-2171**               **1600**                 **2400**
  Poises**                                                                       

  **Viscosity @ 275°F., cSt.** **D-2170**               **325**                  

  **Flash Point, °F.,**        **D-92**                 **450**                  

  **Ductility @ 77°F (5        **D-113**                **100**                  
  cm/min) cm.**                                                                  

  **Ductility @ 39.2°F (5      **D-113**                **50**                   
  cm/min) cm.**                                                                  

  **Toughness, inch-pounds**   **D-5801**               **110**                  

  **Tenacity, inch-pounds**    **D-5801**               **75**                   

  **Thin Film Oven Test:**                                                       

  **Tests on Residue**                                                           

  **Viscosity @ 140°F.,        **D-2170**               **\--**                  **8000**
  Poises**                                                                       

  **Ductility @ 77°F., (5      **D-113**                **100**                  
  cm/min) cm**                                                                   

  **Ductility @ 39.2°F., (5    **D-113**                **25**                   
  cm/min) cm**                                                                   
  ---------------------------- ------------------------ ------------------------ ------------------------

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Certified test results plus a sample of the bitumen-synthetic rubber
mixture shall be provided for each tank load shipped to the project or
for each mixed batch, whichever is smaller. Samples being tested shall
contain the anti-stripping additive. No material shall be used before
the test results are delivered to the Engineer. The Engineer will
conduct independent acceptance tests on random samples. Material placed
which does not meet specification requirements shall be removed and
replaced at no additional cost to the owner. A temperature-viscosity
curve for the material shall be provided to the Engineer.

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> **Samples shall be taken, however a minimum of one sample shall be
> tested by the Engineer to verify the submitted certification.
> Additional samples shall be tested if results are borderline or for
> any other reason. The initial test is recommended to be done early in
> the project.**

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**402-2.4 ANTI-STRIPPING AGENT.** Any anti-stripping agent or additive
if required shall be heat stable, shall not change the asphalt cement
viscosity beyond specifications, shall contain no harmful ingredients,
shall be added in recommended proportion by approved method, and shall
be a material approved by the Department of Transportation of the State
in which the project is located.

COMPOSITION

**402‑3.1 COMPOSITION OF MIXTURE**. The porous friction course shall be
composed of aggregate, filler, bituminous material-synthetic rubber
mixture, and anti-stripping agent.

**402‑3.2 JOB MIX FORMULA**. No bituminous mixture shall be produced for
payment until the Engineer has given written approval of the job mix
formula. The job mix shall be prepared by a certified laboratory at the
Contractor's expense and shall remain in effect for the duration of the
project. The job mix formula shall establish a single percentage of
aggregate passing each required sieve size, a single percentage of
bituminous material to be added to the aggregate, the amount of anti
strip agent to be added (minimum of one half of one percent by weight),
and a single temperature for the mixture as it is discharged into the
hauling units. Silicone may be added to the mixture at a maximum rate of
1 ounce per 5,000 gallons of asphalt to facilitate laydown and rolling.
Proper asphalt content shall be determined by mixing trial batches in
the laboratory.

The job mix formula shall be submitted to the Engineer at least \[30\]
days prior to the start of paving and shall include:

**a.** Percent passing each sieve size and gradation requirements.

**b.** Percent of asphalt cement.

**c.** Asphalt viscosity.

**d.** Mixing temperature range.

**e.** Temperature of mix when discharged from the mixer.

**f.** Temperature viscosity relationship of the asphalt cement.

**g.** Percent of wear (LA abrasion).

**h.** Plasticity Index and Liquid Limit of fine aggregate.

**i.** Percent fractured faces.

**j.** Percent elongated particles.

**k.** Anti-strip agent.

The Contractor shall submit samples to the Engineer, upon request, for
job mix formula verification testing.

The combined aggregate shall be of such size that the percentage
composition by weight, as determined by laboratory sieves, will conform
to the gradation shown in Table 2 when tested in accordance with ASTM C
136.

The gradations in Table 2 represent the limits, which determine the
suitability of the aggregate for use from the source of supply. The
aggregate, as finally selected, shall have a gradation within the limits
designated in Table 2 and shall not vary from the low limit on one sieve
to the high limit on the adjacent sieve, or vice versa, but shall be
uniformly graded from coarse to fine.

#### TABLE 2. AGGREGATE-POROUS FRICTION COURSE

**PERCENTAGE BY WEIGHT PASSING SIEVES**

  ------------------- ----------------- ----------------- -----------------
  **Sieve**           **3/4\" maximum** **1/2\" maximum** **Job-Mix
                                                          (Production)**

                                                          Tolerances \*\*

  3/4\"               100               \-\--             \-\--

  1/2\"               70-90             100               +/- 5%

  3/8\"               40-65             85-95             +/- 5%

  #4                  15-25             30-45             +/- 5%

  #8                  8-15              20-30             +/- 2%

  #30                 5-9               9-17              +/- 2%

  #200                1-5               2-7               +/- 2%

  Bitumen                                                 +/- 0.2%

  [Temperature of                                         [+/- 20 degrees
  Mix]{.underline}                                        F.]{.underline}
  ------------------- ----------------- ----------------- -----------------

> \*\* The gradation job mix tolerance limits will apply if they fall
> outside the master grading band in Table 2 except for the top two
> sieve sizes starting at the 100% passing band. These two sieve size
> bands shall also be additional limits for production.

The gradations shown are based on aggregates of uniform specific
gravity. The percentages passing the various sieves will be subject to
appropriate adjustments by the Engineer when aggregates of varying
specific gravities are used. The adjustments to the job mix gradation
curve should result in a curve of the same general shape as the median
curve of the gradation band in Table 2 and fall within the gradation
band.

The Asphalt Institutes Manual Series No. 2 (MS-2) contains a convenient
procedure for \"adjusting\" the job mix gradation when aggregates of non
uniform specific gravity are proposed for use.

The bituminous content of porous friction courses shall be expressed as
a percentage of the total mix by weight and shall be approved by the
Engineer on the basis of laboratory tests. The materials used in the mix
design shall be the same as those used on the project.

The bituminous content shall be within plus or minus 1 percent of the
value obtained from the formula:

2K~c~ + 4.0

where K~c~ is the surface area constant for that part of the total dry
aggregate that will pass a 3/4\" (19.0 mm) sieve and be retained on the
No. 4 (4.75 mm) sieve. Procedures for determining K~c~ are contained in
the Asphalt Institute\'s Manual Series No. 2 (MS-2). The bituminous
content so estimated is the percentage by weight of the total dry
aggregates and must be converted to the percent by weight of the total
mix in the approved job-mix formula.

The laboratory used to develop the job mix formula shall meet the
requirements of ASTM D 3666. A certification signed by the lab manager
of the laboratory stating that it meets these requirements shall be
submitted to the Engineer prior to the start of construction. The
certification 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.

**402‑3.3 TEST SECTION**. At least one full day prior to full
production, the Contractor shall prepare a quantity of bituminous
mixture according to the approved job mix formula. The amount of mixture
should be sufficient to construct a test section at least 50 feet long
and 20 feet wide, placed in two sections and of the same depth specified
on the plans. The test area will be designated by the Engineer. The
underlying pavement on which the test section is to be constructed shall
be the same as the remainder of the course represented by the test
section. The equipment to be used in construction of the test section
shall be the same type and weight to be used on the remainder of the
course represented by the test section. No bituminous mixture shall be
produced for payment prior to successful placement of and acceptance of
a test strip by the Engineer.

If the test section should prove to be unsatisfactory, the necessary
adjustments to plant operation, and/or placement procedures shall be
made. Additional test sections, as required, shall be constructed and
evaluated for conformance to the specifications. When the test section
does not conform to specification requirements the test section shall be
removed and replaced at the Contractors expense. Full production shall
not begin without approval of the Engineer. Test sections, which conform
to specification requirements, shall be measured and paid in accordance
with Paragraphs 402-5.1 and 402-6.1. The asphalt content may be adjusted
by the Engineer during the test section and will be used as the target
asphalt content.

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> **Note: The AC content should be adjusted during the placement of test
> section. One method to establish the optimum AC content is with the
> use of a glass dish. Various AC content mixes are made in increments
> of 0.5% (5.5%, 6.0%, 6.5%, etc.). The mix that will completely cover
> the bottom of the dish should be used to start the test strip. The AC
> content should then be increased in the test strip until it starts to
> bleed. The content then is decreased by 0.5%.**

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CONSTRUCTION METHODS

**402‑4.1 WEATHER AND SEASONAL LIMITATIONS**. The porous friction course
shall be constructed only on a dry surface when the atmospheric
temperature is 50 F (10 C) and rising (at calm wind conditions) and when
the weather is not foggy or rainy.

**402‑4.2 BITUMINOUS MIXING PLANT**. Plants used for the preparation of
bituminous mixtures shall conform to the requirements of ASTM D 995 with
the following changes:

a\. Requirements for all Plants.

**(1)** **Truck Scales.** The bituminous mixture shall be weighed on
approved scales furnished by the Contractor, or on public scales at the
Contractor's expense. Such scales shall be inspected and sealed as often
as the Engineer deems necessary to assure their accuracy. Scales shall
conform to the requirements of Section 90.

**(2)** **Testing Laboratory.** The Contractor or producer shall provide
laboratory facilities for control and acceptance testing functions
during periods of mix production, sampling, and testing and whenever
materials subject to the provisions of these specifications are being
supplied or tested. The laboratory shall provide adequate equipment,
space, and utilities as required for the performance of the specified
tests.

**(3)** **Inspection of Plant.** The Engineer, or Engineer's authorized
representative, shall have access, at all times, to all parts of the
plant for checking adequacy of equipment; inspecting operation of the
plant; verifying weights, proportions, and materials properties; and
checking the temperatures maintained in the preparation of the mixtures.

**(4)** **Storage Bins and Surge Bins.** Paragraph 3.9 of ASTM D 995 is
deleted.

**402‑4.3 HAULING EQUIPMENT**. Trucks used for hauling bituminous
mixtures shall have tight, clean, smooth metal beds. Petroleum products
shall not be used for coating truck beds. To prevent the mixture from
adhering to them, the beds shall be lightly coated with an approved
asphalt release agent. The truck beds shall be raised to drain any
excess solution before loading the mixture in the trucks. Each truck
shall have a suitable cover to protect the mixture from adverse weather.
If conditions warrant, truck beds shall be insulated and covers shall be
securely fastened so that the mixture will be delivered to the site at
the specified temperature.

**402‑4.4 BITUMINOUS PAVERS**. Bituminous pavers shall be
self-contained, power-propelled units with an activated screed or
strike-off assembly, heated if necessary, and shall be capable of
spreading and finishing courses of bituminous plant-mix material which
will meet the specified thickness, smoothness, and grade.

The paver shall have a receiving hopper of sufficient capacity to permit
a uniform spreading operation. The hopper shall be equipped with a
distribution system to place the mixture uniformly in front of the
screed. The screed or strike-off assembly shall effectively produce a
finished surface of the required smoothness and texture without tearing,
shoving, or gouging the mixture.

The paver shall be capable of operating at forward speeds consistent
with satisfactory laying of the mixture.

Pavers shall be equipped with an automatic grade control system capable
of maintaining the screed elevation as specified herein. The control
system shall be automatically activated from either a reference line or
surface through a system of mechanical sensors or sensor-directed
mechanisms or devices that will maintain the paver screed at a
predetermined transverse slope and at the proper elevation to obtain the
required surface.

The controls shall be capable of working in conjunction with any of the
following attachments:

**a.** Ski-Type device of not less than 30 feet in length or as directed
by the Engineer.

**b.** Taut stringline (wire) set to grade.

**c.** Short ski or shoe.

**d.** Laser controls.

The controls shall be so arranged that independent longitudinal grade
controls can be operated simultaneously on both sides of the machine or
independently on either side. The electronic controls shall be arranged
so that the machine can be controlled automatically, semi-automatically,
or manually.

The automatic equipment shall be capable of controlling the grade to
within plus or minus one-eighth inch and the transverse slope to within
plus or minus one tenth of one percent from the controlling grade.

The machine shall be equipped with a spirit level or other type of slope
indicator that will continuously indicate the average transverse slope
of the screen. Curvature of spirit level tubes shall be as required to
produce a bubble movement of not less than one-eighth inch for each
one-tenth of one percent change in the transverse slope.

The paving machine shall be capable of being equipped with an infrared
joint heater if directed by the Engineer. The output of infrared energy
shall be in the one to six micron range. Converters shall be arranged
end to end directly over the joint to be heated in sufficient numbers to
continuously produce, when in operation, a minimum of 240,000 BTU per
hour. The joint heater shall be positioned not more than one inch above
the pavement to be heated and in front of the paver screed and shall be
fully adjustable. Heaters will be required to be in operation at all
times.

**402‑4.5 ROLLERS**. Rollers shall be steel wheel. Split drum rollers
are not acceptable. They shall be in good condition, capable of
reversing without backlash, and operating at slow speeds to avoid
displacement of the bituminous mixture. The wheels shall be equipped
with adjustable scrapers and sprinkling apparatuses using a water
soluble asphalt release agent, approved by the engineer, to prevent the
bituminous mixture from sticking to the wheels. The number, type, and
weight of rollers shall be sufficient to compact the mixture without
detrimentally affecting the material.

**402‑4.6 PREPARATION OF MINERAL AGGREGATE**. The aggregate for the
mixture shall be dried and heated at the central mixing plant before
entering the mixer. When introduced into the mixer, the combined
aggregate moisture content (weighted according to the composition of the
blend) shall be less than 0.25 percent for aggregate blends with water
absorption of 2.5 percent or less and less than 0.50 percent for
aggregate blends with water absorption greater than 2.5 percent. Water
absorption of aggregates shall be determined by ASTM C 127 and C 128.
The water absorption for the aggregate blend shall be the weighted
average of the absorption values for the coarse aggregate retained on
the No. 4 sieve (4.75 mm) and the fine aggregate passing the No. 4 sieve
(4.75 mm). The water content test will be conducted in accordance with
ASTM C 566. In no case shall the moisture content be such that foaming
of the mixture occurs prior to placement. At the time of mixing, the
temperature of the aggregate shall be within the range specified in the
job mix formula. The maximum temperature and rate of heating shall be
such that no damage occurs to the aggregates. Particular care shall be
taken so that aggregates high in calcium or magnesium content are not
damaged by overheating. The aggregate shall be screened to specified
sizes and conveyed in separate bins ready for mixing with bituminous
material.

**402‑4.7 PREPARATION OF BITUMINOUS MIXTURE**. The bituminous mixture
shall be prepared in a central mixing plant. The mixture shall be
prepared at the temperature designated by the mix design.

The dry aggregate shall be combined in the plant using the proportionate
amounts of each aggregate size required to meet the specified gradation.
The quantity of aggregate for each batch shall be determined, measured,
and conveyed into the mixer.

The quantity of bituminous material for each batch or the calibrated
amount for continuous mixers shall be determined by the certified
laboratory that prepared the mix design. It shall be measured by weight
and introduced into the mixer within the temperature range specified in
the job mix formula. For batch mixers, all aggregates shall be in the
mixer before the bitumen material is added. In no case shall the
temperature of the aggregate be more than 25°F above the temperature of
the bituminous material. Mixing shall continue until all particles are
coated uniformly. In no case shall the bituminous mixture be stored in
storage silos or surge bins.

**402‑4.8 TRANSPORTATION AND DELIVERY OF THE MIXTURE**. The mixture
shall be placed at a temperature between 250°F and 300°F. Loads shall be
sent from the plant so that all spreading and compacting of the mixture
may be accomplished during daylight hours. Excessive waiting or delay of
haul trucks at the job site shall not be allowed and mix supplied at
temperatures outside the specified range will not be accepted. Bleeding
and rich spots resulting from segregation during transportation shall
not be accepted.

**402‑4.9 SPREADING AND LAYING**. Immediately before placing the porous
friction course, the underlying course shall be cleared of all loose or
deleterious material with power blowers, power brooms, or hand brooms as
directed. A tack coat conforming to Item P-603 Bituminous Tack Coat
shall be placed on all existing surfaces for bonding the PFC to the
existing surface. Placement of the PFC must be delayed until the tack
coat has properly cured.

The mixture shall be deposited from haul units directly into the laydown
machine hopper and placed in a continuous operation.

Hauling over material already placed shall not be permitted until the
material has been thoroughly compacted and allowed to cure for a period
of at least 12 hours.

**402‑4.10 COMPACTION OF MIXTURE**. After spreading, rolling shall be
done immediately. Two or four passes, at the discretion of the Engineer,
with a steel wheel roller weighing no more than 10 tons, shall be made
for compaction. Care should be taken to avoid over rolling or rolling
when material is too cool. To prevent adhesion of the mixture to the
roller, the wheels shall be kept properly moistened using a water
soluble asphalt release agent approved by the engineer. Rolling
operations shall be conducted in such a manner that shoving or
distortion will not develop. The amount of rolling shall be limited to
only that necessary for compacting the porous friction course and
bonding it to the underlying surface course. Any mixture, which becomes
loose, broken, mixed with dirt, or in any way defective, shall be
removed and replaced with fresh mixture and immediately compacted to
conform to the surrounding area. Such rework shall be done at the
Contractor\'s expense. Spreading of the mixture shall be done carefully
with particular attention given to making the operation as continuous as
possible. Hand working shall be kept to an absolute minimum.

Contractor quality control shall utilize a nuclear gauge to monitor
compaction efforts.

**402‑4.11 JOINTS**. The formation of all joints shall be made in such a
manner as to ensure a continuous bond between old and new sections of
the course. All joints shall present the same texture, density, and
smoothness as other sections of the course.

The roller shall not pass 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, in which case the edge shall be cut
back to its full depth and width on a straight line to expose vertical
face. In both methods all contact surfaces shall be given a tack coat of
bituminous material before placing any fresh mixture against the joint.

Longitudinal joints which are irregular, damaged, or otherwise defective
shall be cut back to expose a clean, sound surface for the full depth of
the course. All contact surfaces shall be given a tack coat of
bituminous material prior to placing any fresh mixture against the
joint. The longitudinal joint shall offset that in the existing course
by at least 1 foot (30 cm).

**402‑4.12 SHAPING EDGES**. While the surface is being compacted and
finished, the Contractor shall carefully shape the longitudinal outside
edges of the PFC to a vertical face at the established edge. When
transitioning from PFC to existing pavement, transverse edges shall be
constructed with a finer graded bituminous mixture.

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> **Edge lips shall not exceed 3-inches; however, they are preferred to
> be less than 1.5-inches. This may be a problem on projects that have
> excessive surface irregularities.**

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**402‑4.13 SURFACE TESTS**. The Contractor is responsible for supplying
an acceptable metal 12-foot straight edge. After completion of final
rolling, the finished surface shall be tested with the 12-foot
straightedge and shall not vary more than 1/4 inch. The 12-foot straight
edge shall be applied parallel with and at right angles to the runway
centerline in a pattern that includes longitudinal and transverse
joints. The 12-foot straightedge shall be advanced approximately 1/2 its
length in the line of measurement. Areas of the porous friction course
exceeding the specified tolerances shall be removed, as directed by the
Engineer, and replaced with new material at the Contractor\'s expense.
The Engineer shall immediately notify the Contractor of such
unsatisfactory visual defects such as non-uniform texture, roller marks,
bleeding of bituminous material, cracking and shoving of the mixture
during rolling operations. Areas of the porous friction course, which
possess such defects, shall be removed, as directed by the Engineer, and
replaced with new material at the Contractors expense. Skin patching or
hand working shall not be permitted.

**402‑4.14 ACCEPTANCE SAMPLING AND TESTING OF BITUMINOUS MATERIAL AND
AGGREGATE.** The Engineer, at no cost to the Contractor, shall perform
all acceptance sampling and testing. The testing laboratory performing
the testing shall meet the requirements of ASTM D 3666.

Samples of the PFC mixture shall be taken at the point of discharge in
hauling units and tested to control uniformity in bituminous content and
gradation. Samples shall be taken in accordance with ASTM D 979 and
prepared in accordance with ASTM D 2172 or ASTM D 6307. One sample shall
be taken from each lot on a random basis in accordance with procedures
contained in ASTM D 3665. A lot shall consist of 1,000 tons or 1/2 day's
production, whichever is less. Should the average bituminous content for
any two consecutive lots not fall within job mix tolerances under
402‑3.1, the Contractor shall cease production until such
out‑of‑tolerance conditions have been remedied. Any material, placed
after the contractor has been informed of two consecutive failing tests,
shall be rejected and removed at the Contractor\'s expense.

Aggregate from each hot bin or aggregate feed shall be sampled on a
random basis and tested for gradation analysis in accordance with ASTM C
136. One sample shall be taken on a random basis in accordance with ASTM
D 3665 for each lot. A lot shall consist of 500 tons or 1/4 day's
production, whichever is less. If any two consecutive samples fail to
meet the tolerances of the job mix formula gradation, the Contractor
shall cease plant production until such out‑of tolerance conditions have
been remedied. Any material, placed after the contractor has been
informed of two consecutive failing tests, shall be rejected and removed
at the Contractor\'s expense.

The Engineer will notify the Contractor of unsatisfactory visual defects
in the completed bituminous friction course such as non-uniform texture,
roller marks, bleeding of bituminous material, cracking and shoving of
the mixture during the roller operations, or nonconformance to the
surface smoothness criteria specified. Unsatisfactory bituminous
friction course shall be removed and replaced at the Contractor\'s
expense as directed by the Engineer.

**402‑4.15 BITUMINOUS AND AGGREGATE MATERIAL (CONTRACTOR'S
RESPONSIBILITY)**. Samples of the bituminous and aggregate materials
that the Contractor proposes to use, together with a statement of their
source and character, shall be submitted for approval prior to use. The
Contractor shall require the manufacturer or producer of the bituminous
and aggregate materials to furnish material subject to this and all
other pertinent requirements of the contract. Only those materials that
have been tested and approved for the intended use shall be acceptable.

The Contractor shall furnish the vendor's certified test reports for
each carload or equivalent of bituminous material shipped to the
project. The report shall be delivered to the Engineer before permission
is granted to use the material. The vendor's certified test report for
the bituminous material shall not be interpreted as a basis for final
acceptance. All test reports shall be subject to verification by testing
sample materials received for use on the project.

**402‑4.16 PROTECTION OF PAVEMENT**. After final rolling, no vehicular
traffic of any kind shall be permitted on the pavement until it has
cured at least 12 hours or unless otherwise authorized by the Engineer.
Newly constructed pavement areas shall not be opened to aircraft traffic
until 24 hours after completion or unless otherwise authorized by the
Engineer.

METHOD OF MEASUREMENT

**402‑5.1** Porous friction course shall be measured by the number of
**\[square yards (square meters)\]\[tons (kg)\]** of mixture used in the
accepted work.

Only the areas of the porous friction course meeting the following
thickness requirements shall be measured for payment:

To determine the thickness of the finished PFC, the Engineer shall take
one core sample, not less than 2 inches (5 cm) in diameter, at random
from each unit of the completed PFC area. A unit of the completed area
shall be one paving lane wide by 1,000 feet (304 m) long. The last unit
in any one paving lane shall include any remaining length in addition to
the 1,000 feet (304 m).

When the measurement of any core is more than the maximum or less than
the minimum allowable thickness, as shown in Table 3, additional cores
shall be taken at 20‑foot intervals (6 m) (parallel to and at right
angles to the runway centerline) until the completed PFC is within such
maximum or minimum thickness for the subunit being tested.
Out‑of‑tolerance areas shall be deducted from the total **\[square yards
(square meters)\]\[tons (kg)\]** PFC for payment. If, in the Engineer's
judgment, such out of tolerance areas warrant removal, the PFC shall be
removed and the underlying course shall be cleaned (ready for
reconstruction), all at the Contractor's expense.

**TABLE 3. ALLOWABLE FINISHED PFC THICKNESS**

Nominal Maximum Minimum

in. mm in. mm in. mm

3/4 in. aggregate 1.0 25 1.50 37 0.75 19

1/2 in. aggregate 0.75 19 1.25 32 0.50 12

BASIS OF PAYMENT

**402‑6.1** Payment shall be made at the respective contract prices per
**\[square yard (square meter)\]\[ton (kg)\]** for porous friction
course and per **\[gallon (liter)\]\[ton (kg)\]** for bituminous
material. The prices shall be full compensation for furnishing all
materials; for all preparation and storage of materials; for cleaning
the existing surface; for mixing, hauling, placing, and compacting the
mixture (including initial test section); and for all tools, equipment,
and incidentals necessary to complete each item. No separate payment is
included in the contract for furnishing and batching mineral filler, or
anti-stripping agents, should such items be required.

Rehabilitation of the existing pavement surface and the tack coat shall
be measured and paid for at their respective contract prices.

Payment will be made under:

Item P‑402‑6.1 Porous Friction Course---**\[per square yard (square
meter)\]\[ton (kg)\]**

Item P‑402‑6.2 Bituminous material---**\[per gallon (liter)\]\[ton
(kg)\]**

TESTING REQUIREMENTS

ASTM C 88 Soundness of Aggregates by Use of Sodium Sulfate or Magnesium
Sulfate

ASTM C 127 Density, Specific Gravity, and Absorption of Coarse
Aggregates

ASTM C 128 Density, Specific Gravity, and Absorption of Fine Aggregate

ASTM C 131 Resistance to Abrasion of Small Size Coarse Aggregate by Use
of the Los

Angeles Machine

ASTM C 136 Sieve Analysis of Fine and Coarse Aggregates

ASTM C 566 Total Evaporable Moisture Content of Aggregate by Drying

ASTM D 693 Crushed Aggregate for Macadam Pavements

ASTM D 979 Sampling Bituminous Paving Mixtures

ASTM D 995 Mixing Plants for Hot-Mixed Hot-Laid Bituminous Paving
Mixtures

ASTM D 2172 Quantitative Extraction of Bitumen from Bituminous Paving
Mixtures

ASTM D 2741 Susceptibility of Polyethylene Bottles to Soot Accumulation

ASTM D 3665 Random Sampling of Paving Materials

ASTM D 3666 Minimum Requirements for Agencies Testing and Inspecting
Bituminous Paving Materials

ASTM D 4318 Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D 6307 Standard Test Method for Asphalt Content of Hot Mix Asphalt
by Ignition Method

MATERIAL REQUIREMENTS

ASTM D 242 Mineral Filler for Bituminous Paving Mixtures

ASTM D 3381 Viscosity‑Graded Asphalt Cement for Use in Pavement
Construction

**END OF ITEM P‑402**

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